Sonochemistry (Applications of Ultrasound in Chemical Synthesis and Reactions): a Review Part III

Journal of Pharmaceutical Research International

31(6): 1-19, 2019; Article no.JPRI.53191 ISSN: 2456-9119 (Past name: British Journal of Pharmaceutical Research, Past ISSN: 2231-2919, NLM ID: 101631759)

Sonochemistry (Applications of Ultrasound in Chemical Synthesis and Reactions): A Review Part III

Menshawy A. Mohamed1,2*

1Department of Pharmaceutical Chemistry, College of Pharmacy, Prince Sattam Bin Abdulaziz University, P.O.Box- 173, Al-Kharj 11942, Saudi Arabia. 2Department of Organic Chemistry, Faculty of Pharmacy, Al-Azhar University, Cairo, Egypt.

Author’s contribution

The sole author designed, analysed, interpreted and prepared the manuscript.

Article Information

DOI: 10.9734/JPRI/2019/v31i630363 Editor(s): (1) Dr. Wenbin Zeng, Xiangya School of Pharmaceutical Sciences, Central South University, China. Reviewers: (1) Dr. Keshav Badhe, Mumbai University, India. (2) Omyma Abd Elaziz Abd El-Latif Abd Allah, Sohag University, Egypt. Complete Peer review History: http://www.sdiarticle4.com/review-history/53191

Received 04 October 2019 Accepted 16 December 2019 Review Article Published 25 December 2019

ABSTRACT

As the need for friendly environment increasing the need for Sonochemistry increasing. Sonochemistry has become an important field of research for organic synthesis of diverse types of reactions, that decrease environmental hazardous and increase the yield of those reactions. The aim is to continue reviewing applications of ultrasound in chemical synthesis and reactions as reported in part I [1] and part II [2]. In this article I am trying to illustrate green sonochemical approaches for organic synthesis as one of the applications of ultrasound that minimize or eliminate the use and generation of hazardous substances and reduce environmental pollution.

Keywords: Ultrasound; chalcones; heterocyclic compounds.

1. INTRODUCTION from a phenomenon known as acoustic cavitation (formation, growth and Sonochemistry is a powerful field of research in implosion of microbubbles inside a liquid) that organic synthesis and pharmaceutical industry induce high temperature (near 5000 K) and high [3-5], where sonochemical effects are derived pressure (around 1000 atm.) [6]. ______

*Corresponding author: E-mail: [email protected], [email protected];

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Sonochemistry is used for synthesis of different chalcones with a Licochalcone A-like structure types of compounds with versatile applications. which exhibit pharmacological activity against one of those applications is the green approach Staphylococcus aureus. As shown in Fig. 1. which is being used to accelerate synthesis of organic compounds and reduce the 2.1.2 Synthesis of chalcones environmental pollutions which is a complaint from a traditional methods for synthesis of Na-and Cs-Norit activated charcoal have been organic compounds. The green chemistry tools successfully used as catalysts in sonochemical include using alternative material such as chalcone preparation as a valid green alternative reagents, solvents and catalysts [7]. to the traditional use of NaOH (Carlos Javier Dura`n-Valle, et al. [9]. As shown in Fig. 2. 2. GREEN SONOCHEMICAL APPROA- CHES FOR ORGANIC SYNTHESIS 2.1.3 Synthesis of N-substituted imidazoles

2.1 Solvent-free Sonochemical Protocols Lo´pez-Pestan˜a, et al. [10] to the ultrasound- assisted synthesis of N-substituted imidazoles 2.1.1 Synthesis of licochalcones A-like via alkylation with 1-bromobutane and propargyl structure bromide. Under heterogeneous catalysis, ultrasonic irradiation plays a pivotal role in surface The literature offers several interesting examples cleaning, particle size reduction, and metal of ultrasonic activation in “neat reactions,” which activation, explaining the much higher yield in N- have been an attractive option since the dawning substituted imidazole synthesis. There is also a of synthetic chemistry. Chalcones, important reduction in energy consumption and waste intermediates in the synthesis of many generation. As shown in Fig. 3. pharmaceuticals, are commonly synthesized via the Claisen–Schmidt condensation between 2.1.4 Synthesis of α-aminophosphonates acetophenone and benzaldehyde, principally under homogeneous acid or base catalysis. Niralwad, et al. [11] have reported the first ever Martin-Aranda [8] have described a heteroge- use of a 1-hexanesulfonic acid sodium salt for neous condensation reaction that is catalyzed by the synthesis of α-aminophosphonates under amino-zeolites (solid phase) in which both ultrasound irradiation in solvent-free conditions. catalyst preparation and the reaction were A versatile method was described, which enables performed under ultrasound. In this green, the reaction to be carried out with variously solvent-free procedure, chalcones were substituted aryl/heteroaryl aldehydes/ketones, selectively produced in high yields (>95%). A amines, and triethyl phosphates, giving faster combination of sonocatalysis and NH2-zeolites conversion, higher selectivity, and an easier was applied for the synthesis of commercial workup. As shown in Fig. 4.

Fig. 1. Synthesis of Licochalcone A-like structure

Fig. 2. Synthesis of chalcones

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Fig. 3. Synthesis of N-substituted imidazoles

Fig. 4. Synthesis of α –aminophosphonates

2.2 Heterogeneous Catalysis in Organic sources. Karla, et al. [13] screened a wide variety Solvents and Ionic Liquids of promoters (alumina, silica, etc.) to imine synthesis under ultrasound irradiation using 2.2.1 Epoxidation reactions benzaldehyde and p-methoxyaniline as model compounds in ethanol. The reusability of the The catalytic epoxidation of C=C double bonds is solid promoter was checked over several cycles a versatile transformation in synthetic organic and reactivation was achieved by heating in an chemistry due to the synthetic utility of the oven for 4h. As shown in Fig. 6. ensuing epoxides and their further functionalization. Increased environmental concerns and awareness have resulted in a greater demand for environmentally friendly protocols that use relatively benign oxidants such as molecular oxygen and hydrogen peroxide in combination with reusable and recyclable solid catalysts. Hydrotalcites or anionic clays are homogenous basic mixed hydroxides with a brucite-like layer structure. They are known to be highly active catalysts in the H2O2 based epoxidation of olefins in the presence of a nitrile. An efficient and environmentally friendly epoxidation protocol for olefins and α,β- Fig. 5. Epoxidation reactions unsaturated ketones using hydrotalcite catalysts in the presence of acetonitrile and H2O2 under 2.2.3 Synthesis of 1,8-dioxo-octahydroxan- ultrasound has been proposed by Pillai, et al. thene [12]. The main advantages of the sonochemical method include a significant reduction in catalyst The use of non-aqueous room temperature ILs in amount and reaction time, with a similar or organic transformations has gained considerable improved product yield as that of conventional importance due to their negligible vapor heating and stirring. The protocol is equally pressure, reusability, and good thermal stability. efficient for the selective epoxidation of α,β- An efficient methodology for the synthesis of 1,8- unsaturated ketones. As shown in Fig. 5. dioxooctahydroxanthene derivatives under ultrasonic irradiation at room temperature using 2.2.2 Imines formation carboxy-functionalized IL 1-carboxymethyl-3- methylimidazolium tetrafluoroborate, [cmmim] Authors have investigated greener synthetic [BF4], without any added catalyst, has been protocols that make use of alternative energy described by Dadhania, et al. [14]. The reaction

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involves a condensation between 5,5-dimethyl- 2.2.5 Synthesis of polyurethanes 1,3-cyclohexanedione (dimedone) and structurally diverse aldehydes. The resulting Naturally occurring oleic and undecylenic acids products were obtained in excellent isolated were used as raw materials in the synthesis of yields and high purity. The IL was recycled and novel polyurethanes (PUs). Gonza`lez-Paz, et al. its activity was largely retained for up to at least [16] have described a novel route to diols from six cycles. The beneficial features of the reaction, fatty acids. The application of environmentally such as its mild conditions, the absence of a friendly thiol-ene additions to 10-undecenoate catalyst, and the reusability of the IL are much and oleate derivatives was investigated with the more environmentally friendly than any goal of obtaining renewable diols. The conventional acid/base-catalyzed reaction. As application of thiol-ene additions to 10- shown in Fig. 7. undecenoate and oleate derivatives was carried out in order to obtain the required monomers. 2.2.4 Isatins oxidation The resulting monomers were then polymerized with 4,4-methylene-bis(phenylisocyanate) in Isatoic anhydrides are generally used as DMF solution, using tin (II) 2-ethylhexanoate as a intermediates in organic synthesis and lead to a catalyst, to produce the corresponding wide variety of compounds and building blocks, thermoplastic PUs (TPUs). Under sonochemical most often anthranilic acids. A novel, fast and conditions TPUs were obtained in high yields environmentally friendly sonochemical procedure (80–99%) with weight-average molecular weights for the oxidation of isatins has recently been in the 36–83 kDa range and characterized by reported by Deligeorgiev, et al. [15]. The protocol good thermal and mechanical properties (Fig. 9). entails the use of a urea-hydrogen peroxide This means that PUs are excellent candidates for complex in acetic or formic acid. As shown in Fig. the substitution of petroleum-based materials. As 8. shown in Fig. 9.

Fig. 6. Imines formation

Fig. 7. Synthesis of 1,8-dioxo-octahydroxanthene

Fig. 8. Isatins oxidation

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Fig. 9. Polyurethanes preparation

2.2.6 Synthesis of 8-C-glycosylflavanones some of which are routes to quinolines. Conventional Skraup, D€obner–von Miller, Santos, et al. [17] have described an efficient Conrad–Limpach, and Friedlaender green route to C-glycosyl flavanones in one step homogeneous transition metal-catalyzed via the direct glycosylation of an unprotected methods often suffer from hazardous organic flavanone with unprotected and reducing sugars. solvents, long reaction times, low selectivity, and Praseodymium triflate proved to be a suitable the need for excessive amounts of base. Kowsari catalyst for the direct coupling reaction which and Mallak mohammadi, [18] have reported a leads to monoglycosylation products in yields green sonochemical protocol for the synthesis of ranging from 28% to 38% with complete regio- quinolines in water which is catalyzed by basic and stereo-selectivity for 8-C-glycosyl derivatives ILs at room temperature. The reaction of isatin with an equatorial glycosidic bond. The efficiency with acetophenone afforded substituted of this method was significantly improved when quinolines in high yield (90–95%). While the the reactions were assisted by ultrasound reaction under conventional heating required 8h, irradiation (frequency of 45 kHz, power 80 W, under ultrasonic irradiation the reaction occurred temperature 80 C). This resulted in a threefold in only 2 h. As shown in Fig. 11. decrease in the reaction time over conventional heating for the monosaccharidyl derivatives and 2.3.2 Synthesis of 2-imidazolines a fourfold decrease in the reaction time for disac- charidyl counterparts, with the target 8-C- Sant’ Anna Gda, et al. [19] have described a glycosylflavanones obtained in yields of up to sonochemical synthesis of several 2-imidazolines 56%. As shown in Fig. 10. via aldehyde and ethylenediamine condensation in the presence of N-bromosuccinimide. The 2.3 Heterocyclic Synthesis in Water reaction was performed in water, did not require the use of any catalyst, and can be considered 2.3.1 Synthesis of quinolone derivatives extremely advantageous when compared with conventional procedures, giving faster reaction Heterocycle synthesis includes several green rates (12–18 min) and higher purity and yields sonochemical procedures in aqueous media, (84–99%). As shown in Fig. 12.

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Fig. 10. Synthesis of 8-C-glycosylflavanones

Fig. 11. Quinolines preparation

Fig. 12. Synthesis of 2-imidazolines

2.3.3 Four-component synthesis of 2.3.4 Synthesis of 1,8-dioxo-octahydroxan- dihydropyrano [2,3-c] pyrazoles thenes catalyzed by Si-MCM-41-SO3H

Zou, et al. [20] have developed a one-pot four- New silica-based materials that can boast of a component synthesis of dihydropyrano [2,3- well-ordered structure, such as mesoporous Si- c]pyrazoles in water (over 88% yield in 30 min). MCM-41, have been exploited as catalysts in This efficient and versatile ultrasound-assisted recent years Si-MCM-41-SO3H was used by procedure was carried out with several Rostamizadeh, et al. [21] in the synthesis of 1,8- substituted aryl or heteroaryl aldehydes, dioxo-octahydroxanthens from dimedone and an hydrazine, ethyl acetoacetate, and malononitrile. aromatic aldehyde under ultrasonic irradiation. When the reaction was performed under The combined use of MCM-41-SO3H and conventional conditions, lower product yields ultrasound facilitates the intercalation of guest were found in significantly longer reaction times. molecules (reactants) into host nanoreactors. As shown in Fig. 13. The cavitation promotes the insertion of

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reactants into nanocatalyst channels where they 2.4.2 Synthesis of substituted coumarins are accompanied by the inherent acidity of SO3H groups that capable of bonding with the carbonyl Khaligh and Shirini [25] have prepared a poly(4- oxygens of the aldehydes, thus assisting in the vinylpyridinium) perchlorate [P(4-VPH)ClO4], an generation of ionic intermediates through innovative, solid, and reusable catalyst used for reactant activation. As shown in Fig. 14. the synthesis of substituted coumarins via a solvent-free sonochemical Pechmann reaction at 2.3.5 One-pot synthesis of aryl-14-H- room temperature. All instances, except nitro-and dibenzo[a,j]xanthenes. chlorocoumarins, obtained good to excellent yields. As shown in Fig. 18.

The same authors have also used 2.4.3 Synthesis of substituted oxindoles NH4H2PO4/SiO2 as a green catalyst Mahdavinia, et al. [22] for the one-pot synthesis of aryl-14-H- Most of the syntheses of oxindoles lead to 3- dibenzo [a,j] xanthene from aldehyde and β- monosubstituted or 3,3-disubstitutedoxindoles. It naphthol mixtures in H2O under sonication (25 is, however, more difficult to prepare the less kHz). The best results were obtained using stable 3-unsubstituted oxindoles which require 100mg of catalyst (yield of 92%). A wide range of longer reaction times and harsh reaction aromatic aldehydes was employed and all conditions and give unsatisfactory yields. To benzoxanthenes were obtained in high to combat these difficulties, a green, solvent-free excellent yields in a general method that procedure was described by Dandia, et al. [26] tolerated both electron-withdrawing and namely a one-pot clay-catalyzed reaction under electron-donating constituents. As shown in Fig. sonication via Friedel–Craftcyclization. The 15. reaction of substituted anilines with chloroacetyl chloride proceeds via the clay-catalyzed 2.3.6 Synthesis of highly substituted pyrroles intramolecular Friedel–Craft cyclization of the α- chloroacetanilide, which is generated insitu under The ultrasound-assisted two-step synthesis of ultrasound irradiation and leads to several highly substituted pyrroles in aqueous media, in substituted oxindoles while avoiding harsh the absence of a catalyst, was described reaction conditions. As shown in Fig. 19. by Almeida and Faria [23]. The first step was the dimerization of a 1,3-dicarbonyl compound by 2.4.4 Synthesis of 2-aminothiazole derivatives ceric ammonium nitrate (CAN) under In view of the importance of 2-aminothiazole and ultrasound to produce a tetracarbonyl its derivatives, several synthetic methods have derivative. This derivative was then combined been developed over time, however, the with an amine in the absence of any catalysts to Hantzsch reaction of α-halocarbonyl compounds obtain the pyrrole via a Paal Knorr reaction. with thioureas is the method of choice. Poor Electron-donating groups on the amines yields and difficult product recovery have often accelerated pyrrole formation. As shown in Fig. hampered this synthesis. An improved route to 2- 16. (N-arylamino)-4-arylthiazoles under solvent-free conditions and physical activation, such as 2.4 Solvent-free Reactions microwaves, grinding, or ultrasonication, has been reported by Gupta, et al. [27] 2.4.1 Synthesis of 2H-chromen-2-ones Ultrasonication (in a cleaning bath) gave the highest yields (90–97%) inonly1 to 2-1/2h. As Coumarins are typically prepared via Pechmann shown in Fig. 20. reactions with substituted phenols and β-keto esters that usually require long reaction times 2.5 Reactions in Organic Solvents and harsh conditions. An ecofriendly, efficient, and solventless example process has been 2.5.1 Synthesis of 1,5- Benzodiazepine described by Puri, et al. [24]. The reaction was derivatives catalyzed by copper perchlorate under ultrasound irradiation for the synthesis of 2H- With the aim of improving the synthesis of 1,5- chromen-2-ones.The best results were obtained benzodiazepines, Guzen, et al. [28] have at 45–50ºC after 30–50 min of sonication (35 described the preparation of these heterocyclic kHz) and 20 mol % of copper perchlorate. As compounds under milder conditions. 1,5- shown in Fig. 17. Benzodiazepines were synthesized via the

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reaction of o-phenylenediamines with α-diketone nanoparticles under simple stirring in EtOH at or a ketone series under ultrasound irradiation. room temperature, the reactions under Of the several acidic catalysts used, the authors ultrasound led to higher yields and shorter found the best results were obtained with p- reaction times (15–20 min vs. 45–50 min). The toluene sulfonic acid (10 mol %) in nano-CuO catalyst was reused in three cycles dichloromethane, which gave the product in an with only a slight, gradual decrease in activity. As 83% yield at room temperature in only 15 min. As shown in Fig. 22. shown in Fig. 21. 2.5.3 Synthesis of 2-(3,5-dihydro- 1H- pyrazol- 2.5.2 Synthesis of quinoxaline, benzoxzine 1-yl)-4-phenylthiazole derivatives and benzothiazine derivatives Although water is a particularly attractive choice, Extending the application of ultrasound in the most organic compounds are not sufficiently synthesis of heterocyclic compounds was the soluble in it. A quite suitable alternative is the use goal of Sadjadi, et al. [29] when they reported a of ethanol as the reaction medium, since as it is general, efficient, and ecofriendly method for the a bio-renewable product of low cost and low synthesis of quinoxaline, benzoxazine, and toxicity to human health and is relatively benzothiazine that is catalyzed by nonhazardous to the environment. Venzke, et al. nanocrystalline copper (II) oxide under ultrasonic [30] have reported a rapid and facile procedure irradiation. Of the several metallic catalysts used, for the synthesis of 2-(3,5-diaryl-4,5-dihydro-1H- the CuO nanoparticles showed the best activity pyrazol-1-yl)-4-phenylthiazoles via a cyclization and afforded the product in a 94% yield. The involving 1-thiocarbamoyl-3,5-diaryl-4,5-dihydro- increased catalytic activity of nano-CuO over 1H-pyrazoles and phenacyl bromide in ethanol, commercially available bulk CuO may be used as a solvent, at room temperature under attributed to the higher surface area it provides ultrasonic irradiation. The reaction afforded as well as the higher surface reactive site products in high yields in significantly shorter concentration. Compared to reactions carried out times than required under conventional reaction in the presence of the same amount of CuO conditions. As shown in Fig. 23.

Fig. 13. Four-component synthesis of dihydropyrano[2,3-c]pyrazoles

Fig. 14. Synthesis of 1,8-dioxo-octahydroxanthenes catalyzed by Si-MCM-41-SO3H

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Fig. 15. One-pot synthesis of aryl-14-H-dibenzo[a,j]xanthenes

Fig. 16. Synthesis of highly substituted pyrroles

Fig. 17. Synthesis of 2H-chromen-2-ones

Fig. 18. Synthesis of substituted coumarins

Fig. 19. Synthesis of substituted oxindoles

2.5.4 Synthesis of pyrazole derivatives derivatives via the ultrasound-assisted condensation of chalcones with hydrazines in the Pizzuti, et al. [31] have studied the applicability of presence of KOH and ethanol. In detail, the ultrasound to the synthesis of novel pyrazole authors described the synthesis of novel 3,5-

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diaryl-4,5-dihydro-1H-pyrazole-1-carboxamidine using nitriles with electron-withdrawing groups via the reaction of chalcones with results in both higher yields and lower reaction aminoguanidine hydrochloride in KOH. The times. The catalysts were reused several times chalcone derivatives were obtained from without significant loss in catalytic activity. acetophenone and the appropriate aldehydes by Compared to conventional heating, ultrasonic known methods. The mixture of reagents was irradiation reduced reaction times and increased sonicated with a probe for 30 min. The [2+3] catalytic activity. As shown in Fig. 25. cycloaddition of nitriles and azides is a common method for the synthesis of tetrazole derivatives. 2.6 Heterocyclic Functionalization The “click” chemistry approach using zinc as a catalyst in aqueous solution still requires a 2.6.1 Synthesis of spiro[indole-oxathiolanes] tedious and time-consuming workup to remove the zinc salts. As shown in Fig. 24. Several authors have used water as the reaction medium in heterocyclic synthesis. An example 2.5.5 Synthesis of tetrazole derivatives was presented by Dandia, et al. [33] with the preparation of spiro [indole-oxathiolanes] via the Chermahini, et al. [32] have proposed the reaction of spiro [indole-oxiranes] with reaction of a series of aromatic nitriles with thioacetamide in the presence of LiBr under sodium azide catalyzed by montmorillonite K-10 ultrasound irradiation. The reaction was carried or kaolin clays in water or DMF as solvent. out in both a simple cleaning bath and a high- Conventional heating and ultrasonic irradiation intensity probe system, and the two methods were used to promote the reaction and were compared with classical stirring. Under compared. The versatility of this method was ultrasound, yields were higher (80–84% vs. 37% checked using various nitriles, which showed for stirring) and much faster (5 min vs.5h). As reasonable tetrazole yields. It was found that shown in Fig. 26.

Fig. 20. Synthesis of 2-aminothiazole derivatives

Fig. 21. Synthesis of 1,5- Benzodiazepine derivatives

Fig. 22. Synthesis of quinoxaline, benzoxzine and benzothiazine derivatives

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Fig. 23. Synthesis of 2-(3,5-dihydro- 1H- pyrazol-1-yl)-4-phenylthiazole derivatives

Fig. 24. Synthesis of pyrazole derivatives

Fig. 25. Synthesis of tetrazole derivatives

Fig. 26. Synthesis of spiro[indole-oxathiolanes

2.6.2 Synthesis of bis(indolyl)methanes 2.6.3 Synthesis of bis(indol-3-yl)methanes

In general, the synthesis of bis(indolyl)methanes Joshi, et al. [35] used the sodium salt of1- is carried out via the reaction of indole with hexenesulfonic acid as a catalyst in the synthesis aldehydes (or ketones) and catalyzed using of bis(indol-3-yl)methanes. A mixture of 1H- various catalysts, such as protic, Lewis, and solid indole, aldehyde and 1-hexanesulfonic acid acids. Dodecyl benzene sulfonic acid(ABS) was sodium salt (10 mol %) was dissolved in the found to play the dual roles of proton acid minimum quantity of water possible with constant catalyst and emulsifying agent in organic stirring. Furthermore, the reaction mass was synthesis. Li, et al. [34] have reported the use of irradiated under ultrasonic irradiation at ambient dodecyl benzene sulfonic acid as a highly effec- temperature for an appropriate time. This catalyst tive catalyst for the green synthesis of provides clean conversion (94%). Greater bis(indolyl)methanes under ultrasound. The use selectivity and an easy workup make this of an aqueous medium and mild reaction protocol practical and economically attractive. As conditions make this manipulation very shown in Fig. 28. interesting from an economic and environmental point of view. The synthesis of 2.6.4 Synthesis of spiro[indoline-3,4- bis(indolyl)methanes carried out in water at room pyrzolo[3,4-b] pyridine]-2,6(10H)-dione temperature under ultrasound (25 kHz) gave the product in high yield (85–98%). As shown in Fig. Bazgir, et al. [36] have reported a novel and 27. clean synthesis of spiro[indoline-3,4pyrazolo[3,4-

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b]pyridine]-2,6(10H)-dione in a three-component 2(1H)pyridine derivatives with the Vilsmeier– condensation reaction of 4-hydroxycumarin, Haack reagent, has been developed by Ruiz, et isatines, and 1H-pyrazol-5-amines in the al. [37]. This method offers several practical presence of p-toluene sulfonic acid(p-TSA) as an advantages, including faster reaction rates, inexpensive catalyst in water under ultrasonic higher purity, and higher yields as well as cleaner irradiation. The best result was obtained with p- conditions when compared with the conventional TSA as a catalyst in water under ultrasonic thermal method. To determine the influence of irradiation for 6 h at 60ºC. It was observed that a the ultrasonic irradiation source on the lower reaction temperature leads to a lower yield. development of the process, the reactions were As shown in Fig. 29. carried out and monitored using an ultrasonic cleaner and a sonic horn. Both methodologies 2.6.5 Synthesis of 6-chloro-5-formyl-1,4- worked better than the conventional dihydropyridine derivatives method (reaction time of 18h and slightly lower yields (75–80%); they are more efficient, less An efficient and environmentally friendly protocol time consuming, and more environmentally for the synthesis of 6-chloro-5-formyl-1,4- friendly, particularly when considering the dihydropyridine derivatives, which works via the basic green chemistry concepts. As shown in convenient ultrasound-mediated reaction of Fig. 30.

Fig. 27. Synthesis of bis(indolyl)methanes

Fig. 28. Synthesis of bis(indolyl)methanes

Fig. 29. Synthesis of spiro[indoline-3,4-pyrazolo[3,4-b]pyridine]2,6(10H)-dione

Fig. 30. Synthesis of 6-chloro-5-formyl-1,4-dihydropyridine derivatives

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2.6.6 Synthesis of 3(4-oxo-4H-chromen-3-yl) favors mechanical depassivation and enhances acrylic acid hydrazides both mass transfer and electron transfer from the metal to the organic acceptor. The reaction rate It is well known that 3-formylchromones increases still further when simultaneous condense with compounds containing an active ultrasound and microwave irradiation are applied. methylene group. Such condensation reactions The ultrasound-assisted click synthesis has been are achieved using either an acid or base applied for the preparation of a wide range of 1,4 catalyst. Similarly, the condensation reactions of disubstituted 1,2,3-triazole derivatives starting 3-formylchromones with hydrazine, mono from both small molecules and oligomers such substituted hydrazine, hydroxylamine, guanidine, as cyclodextrins (CDs). Using this efficient and and substituted pyrazoles have also been green protocol, all adducts can be synthesized in reported. Joshi, et al. [38] have reported the 2–4h. As shown in Fig. 32. synthesis of 3(4-oxo-4H-chromen-3-yl)acrylic acid hydrazides via the simple Knoevenagel 2.7 Organometallic Reactions condensation of 3-formyl chromones and malonic acid in the presence of pyridine under reflux. This 2.7.1 Reactions in water acid was clubbed with isoniazide using EDCHCl, HOBt in DMF under ultrasound irradiation at 2.7.1.1 Allylindation of 1H-indole-3-carbaldehyde ambient temperature and furnished the desired Cintas, et al. [40] have provided a concise products in excellent yields. When the reaction overview describing how ultrasound acts as a was carried out under conventional heating it fundamental tool in improving the classical one- gave a lower product yield even after a step coupling promoted by zero-valent metal prolonged reaction time (150–180 min). species which are usually referred to as Barbier- However, the reaction was also carried out under like reactions. Sonication has allowed a widening ultrasonication and exhibited excellent product of the applications of the Barbier reaction, yields in short reaction times (35–40 min). As facilitating its extension to other metals and shown in Fig. 31. enabling it to tolerate numerous sensitive 2.6.7 Cu-catalyzed azide- alkyne functional groups, while also promoting the cycloaddition (CuAAC) development of click reactions that use simply metallic copper as an efficient catalyst. The Cintas, et al. [39] have presented a protocol for Barbier allylindation of 1H-indole-3- the ultrasound-assisted 1,3-dipolar cycloaddition carboxaldehyde in the presence of azoles (e.g., reaction of azides and alkynes using metallic pyrazoles and imidazole) under aqueous copper (Cu) as the catalyst. This protocol does conditions has also been studied. The not require additional ligands and proceeds with subsequent dehydration and nucleophilic excellent yields. The Cu-catalyzed azide-alkyne addition were combined in a convergent, one-pot cycloaddition (CuAAC) is generally recognized process for the synthesis of a variety of indole as the most striking example of “click” chemistry. derivatives. Furthermore, the In-assisted Barbier- Reactions involving metals are perhaps the like reaction was exploited in the enantioselective favorite domain of sonochemistry, as ultrasound synthesis of natural convolutamydine A in a

Fig. 31. Synthesis of 3(4-oxo-4H-chromen-3-yl)acrylic acid hydrazides

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Fig. 32. Cu-catalyzed azide-alkyne cycloaddition (CuAAC)

Fig. 33. Allylindation of 1H-indole-3-carbaldehyde three-component one-pot domino reaction, malononitrile and resorcinol at 28–30 Cin water combining the allylindation of 1H-indole-3- or aqueous mixtures using glycine as an carbaldehyde with the dehydrative alkylation of organocatalyst. All chromenes were isolated in stabilized C-nucleophiles (e.g., electron-rich het- excellent yields within 9–45 min in the presence eroarenes, electron-rich aromatics, and stabilized of water alone. To assess the general enols) and N-nucleophiles (e.g., azoles)to applicability of the protocol, a wide range of generate a library of variously functionalized substituted aldehydes were allowed to undergo indolylbutenes. As shown in Fig. 33. this three-component condensation. As shown in Fig. 34. 2.7.1.2 Synthesis of 2-amino-4H-chromenes 2.7.1.3 Synthesis of 2-amino-4,8-dihydropyrano Conceptually, MCRs are potential candidates for [3,2-b]pyran-3-carbonitrile the use of water as a solvent since the multiple hydrophobic reactants are brought into closer Potential biological activity and high reactivity proximity by hydrophobic interactions. MCRs makes kojic acid an attractive molecule in MCRs. under ultrasonic activation have been used as The combination of two important scaffolds, such simple, rapid atom economic and green methods as kojic acid and pyran, may lead to new in organic synthesis. compounds with improved pharmacological profiles. Banitaba, et al. [42] have described a Datta and Pasha [41] have developed a one-pot green and simple approach to assembling of 2- sonochemical multicomponent synthesis of 2- amino4,8-dihydropyrano[3,2-b]pyran-3- amino-4H-chromenes from aromatic aldehydes, carbonitrile scaffolds via the three-component

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reaction of kojic acid, malononitrile, and aromatic solution was reused for the subsequent aldehydes in aqueous media under ultrasound reactions. As shown in Fig. 36. irradiation. This methodology and the combinatorial synthesis were achieved by 2.7.2 Reactions in organic solvents applying ultrasound irradiation, while making use of water as a green solvent. In comparison to 2.7.2.1 Synthesis of 5-amino-7-aryl-7,8dihydro- conventional methods, experimental simplicity, [1,2,4]-triazolo[4,3-a]pyrimidine-6- good functional group tolerance, excellent yields, carbonitriles. a short routine, and selectivity, without the need for a transition metal or base catalyst, are Ablajan, et al. [44] have reported a one-pot prominent features of this green procedure. As synthesis of 5-amino-7-aryl-7,8dihydro-[1,2,4]- shown in Fig. 35. triazolo[4,3-a]pyrimidine-6-carbonitriles via three component reactions of 3-amino-1,2,4-triazole, 2.7.1.4 Synthesis of β-amino carbonyl aromatic aldehydes, and malononitrile in the compounds presence of NaOH in ethanol under ultrasound Kamble, et al. [43] have reported an irradiation at room temperature. Compared with environmentally benign synthesis of β-amino the reflux reaction, no side products were carbonyl compounds in aqueous hydrotropic detected in the sonochemical method. The solution under ultrasound irradiation. The term suggested mechanism of the three-component, hydrotropes refers to a diverse class of water one-pot reaction is assumed to start with a soluble surface active compounds that enhance condensation between aminotriazole and the solubility of organic reactants in the aqueous aldehyde. This intermediate then further reacts phase (up to 200 times). Aqueous hydrotropic with malononitrile via an intramolecular Michael solutions provide an interesting approach to addition followed by isomerization. As shown in controlling the chemical contents of a bubble and Fig. 37. work via a combination of low vapor pressure and increased aqueous hydrotropic solution 2.7.2.2 Synthesis of β-amino ketones viscosity relative to pure water. Chemical control of the vapor content of the collapsing bubble Sulfamic acid (NH2SO3H, SA) has emerged as a allows for a stronger collapse that leads to promising substitute for inorganic solvents greater compressional heating of reactants, conventional Bronsted- and Lewis-acid catalysts. which, in turn, leads to reaction rate acceleration. It is a relatively dry, nonvolatile, non-hygroscopic, Excellent results were obtained with sodium p- noncorrosive, and odorless crystalline solid with toluene sulfonate (50% w/ v) aqueous solutions outstanding physical stability. It possesses of selected hydrotropes, since this concentration distinctive catalytic features which are related to was suitable for the maximum solubilization of its zwitter ionic nature and displays excellent organic compounds. The aqueous hydrotrop activity over a vast array of acid-catalyzed

Fig. 34. Synthesis of 2-amino-4H-chromenes

Fig. 35. Synthesis of 2-amino-4,8-dihydropyrano[3,2-b]pyran-3-carbonitrile

Mohamed; JPRI, 31(6): 1-19, 2019; Article no.JPRI.53191

Fig. 36. Synthesis of β-amino carbonyl compounds

Fig. 37. Synthesis of 5-amino-7-aryl-7,8dihydro-[1,2,4]-triazolo[4,3-a]pyrimidine-6-carbonitriles

Fig. 38. Synthesis of β-amino ketones organic transformations. Zeng, et al. [45] have industry specially pharmaceutical industry. The reported an ultrasound-assisted one-pot efficient synthesis of drugs with high yield and approach to direct Mannich reactions of less environmental hazardous Increases the aldehydes, ketones, and amines in absolute need for future using ultrasound technologies in EtOH, catalyzed by SA, which lead to the rapid pharmaceutical preparations and drug delivery and efficient synthesis of β-amino ketones under systems. mild conditions. SA efficiently catalyzed the Mannich reaction which afforded the desired CONSENT products in high yields (80–95%). Thus, in view of its excellent catalytic capacity, easy It is not applicable. availability, cost effectiveness, outstanding stability, and ready recovery, SA was proven to ETHICAL APPROVAL be the best catalyst for such sonochemical It is not applicable. Mannich reactions. As shown in Fig. 38.

3. CONCLUSION AKNOLEDGEMENT

The primary focus of my work is to give a light to The author would like to thank the Deanship of a different types of sonochemistry applications, Scientific Research at Prince Sattam Bin which becomes an interesting and pivotal for Abdulaziz University.

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COMPETING INTERESTS 12. Pillai UR, Sahle-Demessie E, Varma RS. Ultrasound-assisted epoxidation of olefins Author has declared that no competing interests and α,β-unsaturated ketones over exist. hydrotalcites using hydrogen peroxide. Synth. Commun. 2003;33(12):2017–2027.

REFERENCES 13. Karla P, Guzen KP, Alexandre S, Guarezemini AS, Orfao ATG, Cella R, 1. Menshawy A Mohamed. Sonochemistry Pereira CMP, Stefani HA. Eco-friendly (Applications of ultrasound in chemical synthesis of imines by ultrasound synthesis and reactions): A review part I, irradiation. Tetrahedron Lett. 2007;48: Az J. Pharm. Sci.2016;53:117-134. 1845–1848. 2. Menshawy A Mohamed. Sonochemistry 14. Dadhania AN, Patel VK, Raval DK. (Applications of ultrasound in chemical Catalyst-free sonochemical synthesis of synthesis and reactions): A review part II, 1,8-dioxo-octahydroxanthene derivatives in Advaces in Bioresearch. 2017;8(4). carboxy functionalized ionic liquid. CR. 3. Baker KG, Robertson VJ, Duck FA. A Chimie. 2012;15:378–383. review of therapeutic ultrasound: 15. Deligeorgiev T, Vasilev A, Vaquero JJ, Biophysical effects, Phys. Ther. 2001;81: Alvarez-Builla J. A green synthesis of 1351–1358. isatoic anhydrides from isatins with urea- 4. Cobbold RS. Foundations of Biomedical hydrogen peroxide complex and Ultrasound, Oxford University Press, ultrasound. Ultrason Sonochem. 2007; Demand; 2007. 14:497–501. 5. Cartee RE, Selcer BA, Hudson JA, Finn- 16. Gonza`lez-Paz RJ, Lluch C, Lligadas G, Bodner ST, Mahaffey MB, Johnson PL, Ronda JC, Galia M, Cadiz V. A green Marich K. Practical veterinary ultrasound, approach toward oleic-and undecylenic Williams & Wilkins; 1996. acid-derived polyurethanes. J. Polym. Sci. 6. Richard James Wood, Judy Lee, A Polym. Chem. 2011;49:2407–2416. Madeleine J Bussemaker. A parametric 17. Santos RG, Xavier NM, Bordado JC, review of sonochemistry: Control and Rauter AP. Efficient and first regio-and augmentation of sonochemical activity in stereoselective direct C-glycosylation of a aqueous solutions. Ultrasonics flavanone catalysed by Pr(OTf)3 under Sonochemistry. 2017;38:351–370. conventional heating or ultrasound 7. Jyoti Mathela, Singh BK. A Review On irradiation. Eur. J. Org. Chem. 2013;1441– Green Approach in Chemistry World 1447. Journal of Pharmaceutical Research. 18. Kowsari E, Mallakmohammadi M. 2016;5(10):309-320. Ultrasound promoted synthesis of 8. Martı´n-Aranda RM. Ultrasound-promoted quinolines using basic ionic liquids in N-alkylation of imidazole. Catalysis by aqueous media as a green procedure. solid-base, alkali-metal doped carbons. Ultrason. Sonochem. 2011;18:447– 454. Green Chem. 2004;4:628–630. 19. Sant’ Anna Gda S, Machado P, Sauzem 9. Carlos Javier Dura`n-Valle CJ, Fonseca PD, Rosa FA, Rubin MA, Ferreira J, IM, Calvino-Casilda V, Picallo M, Lo´ pez- Bonacorso HG, Zanatta N, Martins MA. Peinado AJ, Martı´n-Aranda RM. Ultrasound promoted synthesis of 2- Sonocatalysis and alkaline-doped carbons: imidazolines in water: A greener approach An efficient method for the synthesis of toward monoamine oxidase inhibitors. chalcones in heterogeneous media. Catal. Bioorg. Med. Chem. Lett. 2009;19:546– Today. 2005;107–108:500–506. 549.

10. Lo´ pez-Pestan˜a JM, A vila-Rey MJ, 20. Zou Y, Wu H, Hu Y, Liu H, Zhao X, Ji H, Martı´n-Aranda RM. Ultrasound-promoted Shi D. A novel and environment friendly N-alkylation of imidazole. Catalysis by method for preparing dihydropyrano[2,3- solid-base, alkali-metal doped carbons. c]pyrazoles in water under ultrasound Green Chem. 2004;4:628–630. irradiation. Ultrason. Sonochem. 2011;18: 11. Niralwad KS, Shingate BB, Shingare MS. 708–712. Solvent-free sonochemical preparation of 21. Rostamizadeh S, Amani AM, Mahdavinia α-aminophosphonates catalyzed by 1- GH, Amiri G, Sepehrian A. Ultrasound hexanesulphonic acid sodium salt. promoted rapid and green synthesis of 1,8- Ultrason. Sonochem. 2010;17:760–763. dioxo- octahydroxanthenes derivatives

Mohamed; JPRI, 31(6): 1-19, 2019; Article no.JPRI.53191

using nanosized MCM-41-SO3H as a 32. Chermahini AN, Teimouri A, Momenbeik F, nanoreactor, nanocatalyst in aqueous Zarei A, Dalirnasab Z, Ghaedi A, Roosta media. Ultrason. Sonochem. 2010;17:306– M. Clay-catalyzed synthesis of 5- 309. substituent 1-H-tetrazoles. J. Heterocycl. 22. Mahdavinia GH, Rostamizadeh S, Amani Chem. 2010;47:913–922. AM, Emdadi Z. Ultrasound-promoted 33. Dandia A, Singh R, Bhaskaran S. greener synthesis of catalyzed by Ultrasound promoted greener synthesis of NH4H2PO4/SiO2 in water. Ultrason. spiro [indole-3,50-[1,3]oxathiolanes] in Sonochem. 2009;16:7–10. water. Ultrason. Sonochem. 2010;17:399– 23. Almeida QAR, Faria RB. Synthesis of 402. highly substituted pyrroles using 34. Li JT, Sun MX, He GY, Xu XY. Efficient ultrasound in aqueous media. Green and green synthesis of bis(indolyl)meth- Chem. Lett. Rev. 2013;6(2):129–133. anes catalyzed by ABS inaqueous media 24. Puri S, Kaur B, Parmar A, Kumar H. under ultrasound irradiation. Ultrason. Ultrasound-promoted greener synthesis of Sonochem. 2011;18:412–414. 2H-chromen-2-ones catalyzed by copper 35. Joshi RS, Mandhane PG, Diwakar SD, Gill perchlorate in solventless media. Ultrason. CH. Ultrasound assisted green synthesis Sonochem. 2009;16:705–707. of bis(indol-3-yl)methanes catalyzed by 1- 25. Khaligh NG, Shirini F. Introduction of hexenesulphonic acid sodium salt. poly(4-vinylpyridinium) perchlorate as a Ultrason. Sonochem. 2010;17:298–300. new, efficient and versatile solid acid 36. Bazgir A, Ahadi S, Ghahremanzadeh R, catalyst for one-pot synthesis of Khavasi HR, Mirzaei P. Ultrasound- substituted coumarins under ultrasonic assisted one-pot, three-component irradiation. Ultrason. Sonochem. 2013;20: synthesis of spiro[indoline-3,4- 26–31. pyrazolo[3,4-b] pyridine]-2,6 (10H)-diones in water. Ultrason. Sonochem. 2010; 26. Dandia A, Bhati DS, Jain AK, Sharma GN. 17:447–452. Ultrasound promoted clay catalyzed efficient and one pot synthesis of 37. Ruiz E, Rodriguez H, Coro J, Niebla V, substituted oxindoles. Ultrason. Rodriguez A, Martinez-Alvarez R, Novoa Sonochem. 2011;18:1143–1147. de Armas H, Suarez M, Martin N. Efficient sonochemical synthesis of alkyl 4-aryl6- 27. Gupta R, Sharma D, Singh S. Eco-friendly chloro-5-formyl-2-methyl-1,4- synthesis and insecticidal activity of some dihydropyridine-3-carboxylate derivatives. fluorinated 2-(N-arylamino)-4-arylthiazoles. Ultrason. Sonochem. 2012;19:221– 226. Phosphorus Sulfur Silicon. 2010;185: 38. Joshi RS, Mandhane PG, Badadhe PV, 1321–1331. Gill CH. Development of practical meth- 28. Guzen KP, Cella R, Stefani HA. Ultrasound odologies for the synthesis of novel 3(4- enhanced synthesis of 1,5-benzodiazepinic oxo-4H-chromen-3-yl)acrylic acid heterocyclic rings. Tetrahedron Lett. hydrazides. Ultrason. Sonochem. 2011;18: 2006;47:8133–8136. 735–738. 29. Sadjadi S, Sadjadi S, Hekmatshoar R. 39. Cintas P, Barge A, Tagliapietra S, Boffa L, Ultrasound-promoted greener synthesis of Cravotto G. Alkyne-azide click reaction benzoheterocycle derivatives catalyzed by catalyzed by metallic copper under nanocrystalline copper(II) oxide. Ultrason. ultrasound. Nat. Protocol. 2010;5(3):607– Sonochem. 2010;17:764–767. 611. 30. Venzke D, Flores AFC, Quina FH, Pizzuti 40. Cintas P, Palmisano G, Cravotto G. Power L, Pereira CMP. Ultrasound promoted ultrasound in metal-assisted synthesis: greener synthesis of 2-(3,5-diaryl-4,5- from classical barbier-like reactions to click dihydro-1H-pyrazol-1-yl)-4-phenylthiazoles. chemistry. Ultrason. Sonochem. 2011;18: Ultrason. Sonochem. 2011;18:370– 836–841. 374. 41. Datta B, Pasha MA. Glycine catalyzed 31. Pizzuti L, Martins PLG, Ribeiro BA, Quina convenient synthesis of 2-amino-4H- FH, Pinto E, Flores AFC, Venzke D, chromenes in aqueous medium under Pereira CMP. Efficient sonochemical sonic condition. Ultrason. Sonochem. synthesis of novel 3,5-diaryl-4,5-dihydro- 2012;19:725–728. 1H-pyrazole-1-carboximidamides. 42. Banitaba SH, Safari J, Khalili SD. Ultrason. Sonochem. 2010;17:34–37. Ultrasound promoted one-pot synthesis of

Mohamed; JPRI, 31(6): 1-19, 2019; Article no.JPRI.53191

2-amino-4,8-dihydropyrano[3,2-b]pyran-3- 44. Ablajan K, Kamil W, Tuoheti A, Wan-Fu S. carbonitrile scaffolds in aqueous media: A An efficient three component one-pot complementary ‘green chemistry’ tool to synthesis of 5-amino-7-aryl-7,8-dihydro- organic synthesis. Ultrason. Sonochem. [1,2,4] triazolo [4,3-a]-pyrimidine-6- 2013;20:401–407. carbonitriles. Molecules. 2012;17:1860– 43. Kamble S, Kumbhar A, Rashinkar G, 1869. Barge M, Salunkhe R. Ultrasound 45. Zeng H, Li H, Shao H. One-pot three- promoted efficient and green synthesis of component Mannich-type reactions using β-amino carbonyl compounds in aqueous sulfamic acid catalyst under ultrasound hydrotropic medium. Ultrason. Sonochem. irradiation. Ultrason. Sonochem. 2009;16: 2012;19:812–815. 758–762.

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