DOCSLIB.ORG

Haloform Reaction

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Haloform Reaction 19.02.2018 Preparation of Primary Amines Reaction Mechanism of LiAlH4 by Action from Amides ve Nitriles LiAlH4 RCN RCH2 NH2 LiAlH4 R CONH2 RCH2 NH2 O RCH CH • LiAlH4 is converted to alcohols by reducing R‐CHO, R2C=O, R‐COOH, 2 RCOOR, RCOCl molecules. LiAlH4 RCHO RCH2OH Reduction of Carbonyl Derivatives Catalytic Reduction (Hydrogenolysis) with NaBH 4 Hydrogenolysis is called that is opened by hydrogen and a metal catalyser the bond in the ethylenic and acetylenic unsaturated structures and the NaBH4 is a weaker reduction agent than LiAlH4. It is used to reduce bond between carbon and heteroatom. These metals are platinum (Pt), aldehydes and ketones majorly. The reduction process with NaBH4 can be carried out in an aqueous medium or alcohol. rutenium (Ru), palladium (Pd) and nickel (Ni). Examples of Reduction Haloform Reaction using Metal / Acid System • The halogenation of the ‐C atom of many ketone compounds can be carried out in the form of total halogenation in a basic medium. So methyl ketones • It is used Zn, Fe, Sn / HCl, H2SO4 and SnCl2,FeSO4.Whenmetalistreated [CH3‐CO‐] contain three halogen atoms in ‐C and are formed trihalomethyl with acid, the hydrogen gas is formed on the rise. ketones. Zn / HCl O Ar NO2 Ar NH2 base O R C CH + X R CO O - + CH X Zn- Hg 3 2 3 Ar C R Ar CH R HCl, heat 2 O • The haloform reaction takes place via the hypohalogenide derivative of Zn- Hg halogens in basic medium. RCH RCH3 conc. HCl, heat • Zn also reduces in aqueous and alcoholic medium. 8 19.02.2018 Reaction Mechanism Haloform Reaction • The trihalomethyl group of the resulting compound forms a leaving group • General Reaction Equation for the nucleophilic acyl substitution, resulting in the formation of the carboxylated aryl which is displaced by the basic OH‐ group of the O O O X2 , OH OH RCCH3 medium. However, the immediate rapid proton exchange completes the RCCX3 RCO + CHX3 (X=Cl , Br , I ) formation of the haloform derivative with the carboxylate anion. Methyl ketone 2 2 2 Carboxylate Haloform anion Trihalomethylketone .. .. .. izole edilemez .O ..O.. ..O .. RCCX + .OH RCCX RC + . 3 .. 3 .CX3 • Example O O Ext. .OH .OH Br2 .. .. CH3 CH2 CCH3 CH3 CH2 CCBr3 nucleophilic acyl OH substitution OH O O RCO + CHX3 CH3 CH2 CO + CHBr haloform 3 carboxylate Propionate anion Bromoform ion derivative Haloform Reaction Example Haloform Reactions • When halogen is I2, the haloform derivative (iodoform) is a solid compound which can be isolated in the form of a yellow precipitate. This reaction can also be used as a diagnostic reaction for methyl ketones with the so‐called “iodoform test”. However bromoform and chloroform are liquid and volatile. They can not be easily isolated from the reaction medium. O O O C CH3 Ext. I2 OH Ph C CI3 Ph C O + CHI3 OH Benzoate anion Iodoform • Since I2 is an oxidant, a positive iodoform test with alcohols is observed. Because first, the alcohol is oxidized to methyl ketone, followed by the haloform reaction. Benzilic Acid Synthesis General Reaction Equation • Benzilic acid synthesis can be seen as a method of obtaining α‐hydroxy carboxylic acid. The benzilic acid is synthesized by the action of benzaldehyde. • When the benzaldehyde molecule is boiled with KCN in alcoholic medium, the two molecule benzaldehyde gives the benzoin molecule as a condensed molecule. • Benzil molecule with ‐diketone structure is formed by oxidation of benzoin. The benzilic acid salt is formed by the molecular rearrangement (conversion reaction) of this structure in the alkaline solution. Copper(II)acetate (-hydroxy ketone) 9.
Load more

Recommended publications
  • Organic Chemistry
    Wisebridge Learning Systems Organic Chemistry Reaction Mechanisms Pocket-Book WLS www.wisebridgelearning.com © 2006 J S Wetzel LEARNING STRATEGIES CONTENTS ● The key to building intuition is to develop the habit ALKANES of asking how each particular mechanism reflects Thermal Cracking - Pyrolysis . 1 general principles. Look for the concepts behind Combustion . 1 the chemistry to make organic chemistry more co- Free Radical Halogenation. 2 herent and rewarding. ALKENES Electrophilic Addition of HX to Alkenes . 3 ● Acid Catalyzed Hydration of Alkenes . 4 Exothermic reactions tend to follow pathways Electrophilic Addition of Halogens to Alkenes . 5 where like charges can separate or where un- Halohydrin Formation . 6 like charges can come together. When reading Free Radical Addition of HX to Alkenes . 7 organic chemistry mechanisms, keep the elec- Catalytic Hydrogenation of Alkenes. 8 tronegativities of the elements and their valence Oxidation of Alkenes to Vicinal Diols. 9 electron configurations always in your mind. Try Oxidative Cleavage of Alkenes . 10 to nterpret electron movement in terms of energy Ozonolysis of Alkenes . 10 Allylic Halogenation . 11 to make the reactions easier to understand and Oxymercuration-Demercuration . 13 remember. Hydroboration of Alkenes . 14 ALKYNES ● For MCAT preparation, pay special attention to Electrophilic Addition of HX to Alkynes . 15 Hydration of Alkynes. 15 reactions where the product hinges on regio- Free Radical Addition of HX to Alkynes . 16 and stereo-selectivity and reactions involving Electrophilic Halogenation of Alkynes. 16 resonant intermediates, which are special favor- Hydroboration of Alkynes . 17 ites of the test-writers. Catalytic Hydrogenation of Alkynes. 17 Reduction of Alkynes with Alkali Metal/Ammonia . 18 Formation and Use of Acetylide Anion Nucleophiles .
    [Show full text]
  • Packet of Wiser Reports on Acetone Acetonitrile
    Ac&tone ^Hazmat - NFPA Hazard Classification Page 1 of Acetone CAS RN: 67-64-1 Hazmat - NFPA Hazard Classification SOMS DocID 2085807 Health: 1 (Slight) Materials that, on exposure, would cause significant irritation, but only minor residual injury, including those requiring the use of an approved air-purifying respirator. These materials are only slightly hazardous to health and only breathing protection is needed. Flammability: 3 (Severe) rhis degree includes Class IB and 1C flammable liquids and materials that can be easily ignited under almost all normal temperature conditions. Water may be ineffective in controlling or extinguishing fires in such materials. Instability: 0 (Minimal) This degree includes materials that are normally stable, even under fire exposure conditions, and that do not react with water.- Norma lire fighting procedures may be used. Printed by WISER for Windows (v2.3.231, database v2.108) HHS/NIH, National Library of Medicine AR000018 iile://C:\Documents and Settings\Gham\Application Data\National Library of Medicine\WISER\2.3.231.628... 9/27/20 Acetone ^Key Info Page 1 of Acetone CAS RN: 67-64-1 Key Info FLAMMABLE LIQUIDS (Polar / Water-Miscible) • HIGHLY FLAMMABLE: Easily ignited by heat, sparks or flames • CAUTION: Very low flash point; use of water spray when fighting fire may be inefficient Printed by WISER for Windows (v2.3.231, database v2.108) HHS/NIH, National Library of Medicine AR000019 file://C:\Documents and Settings\Gham\Application Data\National Library of Medicine\WISER\2.3.231.628../ 9/27/20 Acetone - -Hazmat - Explosive Limits / Potential Page 1 of Acetone CAS RIM: 67-64-1 Hazmat - Explosive Limits / Potential Highly flammable liquid.
    [Show full text]
  • Chloroform 18.08.2020.Pdf
    Chloroform Chloroform, or trichloromethane, is an organic compound with formula CHCl3. It is a colorless, sweet-smelling, dense liquid that is produced on a large scale as a precursor to PTFE. It is also a precursor to various refrigerants. It is one of the four chloromethanes and a trihalomethane. It is a powerful anesthetic, euphoriant, anxiolytic and sedative when inhaled or ingested. Formula: CHCl₃ IUPAC ID: Trichloromethane Molar mass: 119.38 g/mol Boiling point: 61.2 °C Density: 1.49 g/cm³ Melting point: -63.5 °C The molecule adopts a tetrahedral molecular geometry with C3v symmetry. Chloroform volatilizes readily from soil and surface water and undergoes degradation in air to produce phosgene, dichloromethane, formyl chloride, carbon monoxide, carbon dioxide, and hydrogen chloride. Its half-life in air ranges from 55 to 620 days. Biodegradation in water and soil is slow. Chloroform does not significantly bioaccumulate in aquatic organisms. Production:- In industry production, chloroform is produced by heating a mixture of chlorine and either chloromethane (CH3Cl) or methane (CH4). At 400–500 °C, a free radical halogenation occurs, converting these precursors to progressively more chlorinated compounds: CH4 + Cl2 → CH3Cl + HCl CH3Cl + Cl2 → CH2Cl2 + HCl CH2Cl2 + Cl2 → CHCl3 + HCl Chloroform undergoes further chlorination to yield carbon tetrachloride (CCl4): CHCl3 + Cl2 → CCl4 + HCl The output of this process is a mixture of the four chloromethanes (chloromethane, dichloromethane, chloroform, and carbon tetrachloride), which can then be separated by distillation. Chloroform may also be produced on a small scale via the haloform reaction between acetone and sodium hypochlorite: 3 NaClO + (CH3)2CO → CHCl3 + 2 NaOH + CH3COONa Deuterochloroform[ Deuterated chloroform is an isotopologue of chloroform with a single deuterium atom.
    [Show full text]
  • Electrocatalytic Oxidation of Cyclic Ketones the Reactions on Electrodes, Which Take Place During the Process, Are Usual for the Mediatory System Nai - M
    Electrocatalytic Oxidation of Cyclic Ketones The reactions on electrodes, which take place during the process, are usual for the mediatory system NaI - M. N. Elinson*, S. K. Feducovich, NaOH in methanol and lead to the formation of iodine or A. S. Dorofeev, G. I. Nikishin bromine at the anode and methoxide anions at the N .D. Zelinsky Institute of Organic Chemistry, cathode. Leninsky prospekt 47, 119991 Moscow B-334, Russia Then a-monohalogenation of the enol form of The oxidation of ketones is a way for preparing the ketone takes place. carboxylic acids and their derivatives, bifunctional In the presence of methoxide anions there is an equilibrium between the two possible isomers of compounds such as a-hydroxyketones, diketones and other useful intermediates in organic synthesis. a-halogenoketone 3 posessing either an axial or The formation of adipic acid from cyclohexanone is an equatorial halogen. an important industrial process. a-Halogenoketone 3 thus formed, undergoes reversible The advance of electrooxidation procedures has methoxy anion attack on the carbonyl group with a further provided organic chemists with a synthetic device of intramolecular nucleophilic substitution of the halogen great promise. But in the case of the electrooxidation of and subsequent cyclization to form epoxide 4. O- ketones only some reactions which could provide R O + MeO- R product-selectivity are known. OMe Hal Hal The first attempts of the electrochemical oxidation of 3 A ketones resulted in the formation of a mixture of acids, - OMe O(a ) OMe(e) OMe OMe(e) saturated and unsaturated hydrocarbons, carbon monoxide O MeO- 1 OH and dioxide.
    [Show full text]
  • Electrochemical Haloform Reaction Efficient Transformation of Methyl Ketones to Carboxylates
    J. Jpn. Oil Chem. Soc. Vol. 45, No. 2 (1996) 147 ORIGINAL Electrochemical Haloform Reaction Efficient Transformation of Methyl Ketones to Carboxylates Yoshiharu MATSUBARA * 1, Kazuo FUJIMOTO * 1, Hirofumi MAEKAWA * 2 and Ikuzo NISHIGUCHI * 2 * 1 Department of Applied Chemistry, Faculty of Science and Engineering, Kinki University (3-4-1 Kowakae, Higashi-Osaka-shi, Osaka-fu, •§ 577) * 2 Osaka Municipal Technical Research Institute (6-50, 1-Chome, Morinomiya, Jyoto-ku, Osaka-shi, •§ 536) Abstract : Electrolysis of aliphatic, aromatic, and ƒ¿,ƒÀ-unsaturated methyl ketones in an anhydrous alcohol containing sodium or lithium bromide using an undivided cell equipped with carbon rods as the anode and the cathode brought about electrochemical Haloform reaction to give the corresponding car- boxylates in good to excellent yields. The reaction was found to be mediated with bromonium ion, gen- erated by anodic oxidation of bromide ion. Absence of bromoform in the product mixtures of this reac- tion may be attributed to ready reduction of bromoform to highly volatile compounds, which may pro- vide high simplicity of reaction procedure. Facile and efficient introduction of carboalkoxyl groups to aromatic rings and olefinic bonds was ac- complished in two steps through initial Friedel-Crafts acetylation followed by the present electrochemi- cal method. Key words : mediator, methyl ketones, electrolysis, bromonium ion, carboxylates 1 Introduction Haloform reaction has been well known as a method for transformation of methyl ketones to the corresponding carboxylic acids using an aqueous hypohalite solution1) . Synthetic utili- ty of this reaction, however, has been considerably limited owing to use of large amounts of a hazardous halogen and a strong base, troublesome procedure such as separation and pu- rification of the desired carboxylic acid from the resulting haloform, and unsatisfactory yield.
    [Show full text]
  • Laboratory Classes in Bioorganic Chemistry
    MINISTRY OF HEALTH OF REPUBLIC OF BELARUS VITEBSK STATE MEDICAL UNIVERSITY LABORATORY CLASSES IN BIOORGANIC CHEMISTRY L.G. Hidranovich, O.A. Khodos ( 2 - e « З Д / ) For Foreign students of the 1-st year Vitebsk 20t£ УДК 54 (042.3/4) ББК 24.239 L.G. Hidranovich, О.Л. Khodos LABORATORY CLASSES IN BIOORGANIC CHEMISTRY for foreign students of the 1-sl year: Manual./ L.G. Hidranovich, O.A. Khodos. - Vitebsk: v s m u , 20i b - 128 p. ( 2 - е м а д д ISBN 978-985-466-5$S‘-3 This issue contains program questions, problems, laboratory' works for the classes in bioorgamc chemistry, examination questions, tests, reference tables.The issue was wrote according to the typical educational program for the students o f higher medical educa­ tional establishments. Утверждено и рекомендовано к изданию Центральным учебно-научно­ методическим Советом непрерывного медицинского и фармацевтического образо­ вания Витебского государственного медицинского университета, 21.04________ 2007 г , протокол №4. ISBN 978-985-466-581-3 У Д К 54 (042.3/4) ББК 24.239 © Гидранович Л.Г., Ходос О А., 20/3 ©УО «Витебский государственный медицинский университет», 20'Й CONTENTS Thematic p!a:: of the lectures. 4 Thematic plan of the laboratory classes. 5 Accident prevention. 6 Theme 1. Classification and FJPAC nomenclature of organic com­ 7 pounds. Theme 2. Electronic structure of chemical bonds. Inductive and reso­ 9 nance effects. Theme 3. Stereochemistry of organic compounds. 11 Configuration and conformation of the organic compounds. Theme 4 Acid-base properties of organic compounds. 14 Theme 5. Classification and mechanisms of the reactions in organic 16 chemistry Saturated, unsaturated and aromatic hydrocarbons.
    [Show full text]
  • The Haloform Reaction. Reynold C
    Subscriber access provided by Service des bibliothèques | Université de Sherbrooke The Haloform Reaction. Reynold C. Fuson, and Benton A. Bull Chem. Rev., 1934, 15 (3), 275-309 • DOI: 10.1021/cr60052a001 Downloaded from http://pubs.acs.org on December 30, 2008 More About This Article The permalink http://dx.doi.org/10.1021/cr60052a001 provides access to: • Links to articles and content related to this article • Copyright permission to reproduce figures and/or text from this article Chemical Reviews is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 THE HALOFORM REACTION REYNOLD C. FUSON AND BEE-TON A. BULL Department of Chemistry, University of Illinois, Urbana, Illinois Received September $8, 1934 CONTENTS I. Introduction.. .................... ......... ...............275 11. The early history of the haloform ............................. 276 111. The haloform reaction in qualitative organic analysis 277 IV. Structural determination by means of the haloform degradation.. ...... 281 V. Quantitative methods based on the haloform reaction ................... 286 VI. The use of the haloform reaction in synthesis.. ..... A. The haloforms., ............................. B. Saturated aliphatic acids.. ..................................... 288 C. Unsaturated acids D. Aromatic acids.. .. VII. The mechanism of the haloform reaction.. ............................. 291 A. The halogenation phase of the haloform reaction.. B. The cleavage phase of the haloform reaction .................... 295 VIII. Reactions
    [Show full text]
  • Module: 5 Lecture: 30
    Module:5 Dr. N. K. Patel Lecture:30Chloroform Module: 5 Lecture: 30 CHLOROFOrm INTRODUCTION Chloroform is an organic compound with formula CHCl3. It is a colourless, sweet-smelling dense liquid and it is a trihalomethane which is considered somewhat hazardous. It is one of the four chloromethanes. Chloroform readily volatilizes from soil and surface water, which then produced phosgene, dichloromethane, formyl chloride, carbon monoxide, carbon dioxide and hydrogen chloride as undergoes degradation in air. Chloroform was discovered by three researchers independently of one another. The French chemist EugèneSoubeiran was reported chloroform in 1831. It was prepared from acetone (2-propanone) as well as ethanol through the action of chlorine bleach powder (calcium hypochlorite). Chloroform was named and characterized in 1834 by Jean-Baptiste Dumas. Several million tons are produced annually as a precursor to PTFE and refrigerants, but its use for refrigerants is being phased out. Chloroform has a multitude of natural sources, both abiotic and biogenic. Greater than 90% of atmospheric chloroform is of natural origin. The American physician Samuel Guthrie prepared gallons of the material and described its "deliciousness of flavor." Independently, Justus von Liebig also described the same compound. All early preparations used variations of the haloform reaction. MANUFACTURE 1. From acetone and bleaching powder Raw material Basis: 1000kg chloroform from acetone and bleaching powder (88% yield) Chlorine 1602kg NPTEL 1 Module:5 Dr. N. K. Patel
    [Show full text]
  • Chloroform Systematic N
    有機溶劑中毒預防規則三氯甲烷 Trichloromethane Chloroform From Wikipedia, the free encyclopedia Jump to: navigation, search Chloroform IUPAC name[hide] Chloroform Systematic name[hide] Trichloromethane Other names[hide] Formyl trichloride, Methane trichloride, Methyl trichloride, Methenyl trichloride, TCM, Freon 20, R-20, UN 1888 Identifiers CAS number 67-66-3 PubChem 6212 ChemSpider 5977 UNII 7V31YC746X EC number 200-663-8 KEGG C13827 ChEBI CHEBI:35255 ChEMBL CHEMBL44618 RTECS number FS9100000 SMILES [show] InChI [show] Properties Molecular formula CHCl3 Molar mass 119.38 g/mol Appearance Colorless liquid Density 1.483 g/cm3 Melting point -63.5 °C Boiling point 61.2 °C Solubility in water 0.8 g/100 ml (20 °C) 有機溶劑中毒預防規則三氯甲烷 Trichloromethane Refractive index (nD) 1.4459 Structure Molecular shape Tetrahedral Hazards MSDS External MSDS R-phrases R22, R38, R40, R48/20/22 S-phrases (S2), S36/37 NFPA 704 0 2 0 Flash point Non-flammable U.S. Permissible 50 ppm (240 mg/m3) (OSHA) exposure limit (PEL) Supplementary data page Structure and n, εr, etc. properties Thermodynamic Phase behaviour data Solid, liquid, gas Spectral data UV, IR, NMR, MS (what is this?) (verify) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox references Chloroform in its liquid state shown in a test tube Chloroform is the organic compound with formula CHCl3. The colorless, sweet-smelling, dense liquid is a trihalomethane, and is considered somewhat 有機溶劑中毒預防規則三氯甲烷 Trichloromethane hazardous. Several million tons are produced annually as a precursor to Teflon and refrigerants, but its use for refrigerants is being phased out.[1] Contents [hide] • 1 Occurrence o 1.1 Marine • 2 Production o 2.1 Industrial routes o 2.2 Deuterochloroform o 2.3 Inadvertent formation of chloroform • 3 Uses o 3.1 As a solvent o 3.2 As a reagent in organic synthesis o 3.3 As an anesthetic o 3.4 Veterinary use • 4 Safety o 4.1 Conversion to phosgene • 5 References • 6 External links [edit] Occurrence CHCl3 has a multitude of natural sources, both biogenic and abiotic.
    [Show full text]
  • Chemistry Aldehydes, Ketones and Carboxylic Acids
    CHEMISTRY ALDEHYDES, KETONES AND CARBOXYLIC ACIDS Aldehydes, Ketones and Carboxylic Acids Introduction Carbonyl compounds are organic compounds containing carbon-oxygen double bond . Aldehydes have carbonyl group bonded to a carbon and hydrogen. (Where R = H or alkyl or aryl group) Ketones have carbonyl group bonded to two carbon atoms. (Where R and R’ may be same or different alkyl or aryl groups) Nomenclature of Aldehydes and Ketones Aldehydes Structure Common name IUPAC name CH3CHO Acetaldehyde Ethanal Isobutyraldehyde 2-Methylpropanal Acrolein Prop-2-enal Phenylacetaldehyde 2-Phenylethanal Crotonaldehyde But-2-en-al www.topperlearning.com 2 CHEMISTRY ALDEHYDES, KETONES AND CARBOXYLIC ACIDS Ketones Structure Common name IUPAC name Dimethyl ketone or Propanone Acetone Diethyl ketone Pentan-3-one Methyl phenyl ketone 1-Phenylethan-1-one Mesityl oxide 4-Methylpent-3-en-one Acetylacetone Pentane-2,4-dione Biacetyl Butane-2,3-dione Ethyl phenyl ketone 1-Phenylpropan-1-one Structure and Nature of Carbonyl Group Structure The carbonyl carbon group is sp2 hybridised and forms three sigma bonds. The fourth electron in the p-orbital forms a π-bond by overlapping with p-orbital of oxygen. The oxygen atom also has two non-bonding electron pairs. So the carbonyl carbon with the three atoms linked to it lies in the same plane and the π-cloud lies above and below the plane. The bond angle is 120° with expected trigonal coplanar structure. www.topperlearning.com 3 CHEMISTRY ALDEHYDES, KETONES AND CARBOXYLIC ACIDS Nature The C-O double bond is polarised since oxygen is electronegative than carbon. So the carbonyl carbon is an electrophilic centre and the carbonyl oxygen is a nucleophilic centre.
    [Show full text]
  • Haloform Reaction - Wikipedia
    6/13/2020 Haloform reaction - Wikipedia Haloform reaction The haloform reaction is a chemical reaction where a haloform Haloform reaction (CHX , where X is a halogen) is produced by the exhaustive 3 Named after Adolf Lieben halogenation of a methyl ketone (RCOCH3, where R can be either a hydrogen atom, an alkyl or an aryl group), in the presence of a Reaction type Substitution base.[1][2][3] The reaction can be used to transform acetyl groups into reaction carboxyl groups or to produce chloroform (CHCl3), bromoform Identifiers (CHBr3), or iodoform (CHI3) and also cyanide. Organic haloform-reaction Chemistry Portal Contents Mechanism Scope Applications Laboratory scale Industrially As a by-product of water chlorination History References Mechanism In the first step, the halogen disproportionates in the presence of hydroxide to give the halide and hypohalite (example with bromine, but reaction is the same in case of chlorine and iodine; one should only substitute Br for Cl or I): If a secondary alcohol is present, it is oxidized to a ketone by the hypohalite: If a methyl ketone is present, it reacts with the hypohalite in a three-step process: 1. Under basic conditions, the ketone undergoes keto-enol tautomerization. The enolate undergoes electrophilic attack by the hypohalite (containing a halogen with a formal +1 charge). https://en.wikipedia.org/wiki/Haloform_reaction#Iodoform_reaction 1/5 6/13/2020 Haloform reaction - Wikipedia 2. When the α(alpha) position has been exhaustively halogenated, the molecule undergoes a nucleophilic − acyl substitution by hydroxide, with CX3 being the leaving group stabilized by three electron- − withdrawing groups.
    [Show full text]
  • Organic Chemistry
    ORGANIC CHEMISTRY CARBONYL COMPOUNDS (L-6) B.SC. II BY DR. MONIKA GUPTA Dr. Monika Gupta, Vaish College, Rohtak Oxidation of Aldehydes and Ketones Aldehydes and ketone vary in their oxidation reactions but aldehydes can easily undergo oxidation to form carboxylic acids with known oxidizing agents such as potassium dichromate, potassium permanganate, and nitric acid, etc. Moreover, mild oxidizing agents such as Tollen’s reagents and Fehling’s reagent are also capable of oxidizing only aldehydes. Dr. Monika Gupta, Vaish College, Rohtak Oxidation of Aldehydes Dr. Monika Gupta, Vaish College, Rohtak Oxidation of ketones Oxidation of ketones requires carbon-carbon bond cleavage so that the reaction can produce carboxylic acid containing a lesser number of bonds with respect to the parent ketone. Dr. Monika Gupta, Vaish College, Rohtak Reaction with Mild Oxidizing agents Mild oxidizing agents can be used for distinguishing between aldehydes and ketones. Now, we will how Mild oxidizing agents like Tollen’s reagent and Fehling’s solution is used for distinguishing between the aldehydes and ketones. Dr. Monika Gupta, Vaish College, Rohtak Reaction with Tollen’s Reagent Aldehydes readily undergo oxidation with Tollen’s Reagent whereas ketones are not. Tollen’s reagent is a colourless, basic ammoniacal silver nitrate solution Dr. Monika Gupta, Vaish College, Rohtak Tollen’s Test (Silver Mirror Test) It is a very common qualitative laboratory test help in differentiating between aldehydes and ketones. Aldehydes form silver mirror while ketones does not. Dr. Monika Gupta, Vaish College, Rohtak Fehling’s reagent Fehling’s Reagent consists of a mixture of two solutions (Fehling Solution A & B).
    [Show full text]