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Common Names for Selected Aromatic Groups
More Nomenclature: Common Names for Selected Aromatic Groups Phenyl group = or Ph = C6H5 = Aryl = Ar = aromatic group. It is a broad term, and includes any aromatic rings. Benzyl = Bn = It has a -CH2- (methylene) group attached to the benzene ring. This group can be used to name particular compounds, such as the one shown below. This compound has chlorine attached to a benzyl group, therefore it is called benzyl chloride. Benzoyl = Bz = . This is different from benzyl group (there is an extra “o” in the name). It has a carbonyl attached to the benzene ring instead of a methylene group. For example, is named benzoyl chloride. Therefore, it is sometimes helpful to recognize a common structure in order to name a compound. Example: Nomenclature: 3-phenylpentane Example: This is Amaize. It is used to enhance the yield of corn production. The systematic name for this compound is 2,4-dinitro-6-(1-methylpropyl)phenol. Polynuclear Aromatic Compounds Aromatic rings can fuse together to form polynuclear aromatic compounds. Example: It is two benzene rings fused together, and it is aromatic. The electrons are delocalized in both rings (think about all of its resonance form). Example: This compound is also aromatic, including the ring in the middle. All carbons are sp2 hybridized and the electron density is shared across all 5 rings. Example: DDT is an insecticide and helped to wipe out malaria in many parts of the world. Consequently, the person who discovered it (Muller) won the Nobel Prize in 1942. The systematic name for this compound is 1,1,1-trichloro-2,2-bis-(4-chlorophenyl)ethane. -
Chapter 21 the Chemistry of Carboxylic Acid Derivatives
Instructor Supplemental Solutions to Problems © 2010 Roberts and Company Publishers Chapter 21 The Chemistry of Carboxylic Acid Derivatives Solutions to In-Text Problems 21.1 (b) (d) (e) (h) 21.2 (a) butanenitrile (common: butyronitrile) (c) isopentyl 3-methylbutanoate (common: isoamyl isovalerate) The isoamyl group is the same as an isopentyl or 3-methylbutyl group: (d) N,N-dimethylbenzamide 21.3 The E and Z conformations of N-acetylproline: 21.5 As shown by the data above the problem, a carboxylic acid has a higher boiling point than an ester because it can both donate and accept hydrogen bonds within its liquid state; hydrogen bonding does not occur in the ester. Consequently, pentanoic acid (valeric acid) has a higher boiling point than methyl butanoate. Here are the actual data: INSTRUCTOR SUPPLEMENTAL SOLUTIONS TO PROBLEMS • CHAPTER 21 2 21.7 (a) The carbonyl absorption of the ester occurs at higher frequency, and only the carboxylic acid has the characteristic strong, broad O—H stretching absorption in 2400–3600 cm–1 region. (d) In N-methylpropanamide, the N-methyl group is a doublet at about d 3. N-Ethylacetamide has no doublet resonances. In N-methylpropanamide, the a-protons are a quartet near d 2.5. In N-ethylacetamide, the a- protons are a singlet at d 2. The NMR spectrum of N-methylpropanamide has no singlets. 21.9 (a) The first ester is more basic because its conjugate acid is stabilized not only by resonance interaction with the ester oxygen, but also by resonance interaction with the double bond; that is, the conjugate acid of the first ester has one more important resonance structure than the conjugate acid of the second. -
Metabolic-Hydroxy and Carboxy Functionalization of Alkyl Moieties in Drug Molecules: Prediction of Structure Influence and Pharmacologic Activity
molecules Review Metabolic-Hydroxy and Carboxy Functionalization of Alkyl Moieties in Drug Molecules: Prediction of Structure Influence and Pharmacologic Activity Babiker M. El-Haj 1,* and Samrein B.M. Ahmed 2 1 Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, University of Science and Technology of Fujairah, Fufairah 00971, UAE 2 College of Medicine, Sharjah Institute for Medical Research, University of Sharjah, Sharjah 00971, UAE; [email protected] * Correspondence: [email protected] Received: 6 February 2020; Accepted: 7 April 2020; Published: 22 April 2020 Abstract: Alkyl moieties—open chain or cyclic, linear, or branched—are common in drug molecules. The hydrophobicity of alkyl moieties in drug molecules is modified by metabolic hydroxy functionalization via free-radical intermediates to give primary, secondary, or tertiary alcohols depending on the class of the substrate carbon. The hydroxymethyl groups resulting from the functionalization of methyl groups are mostly oxidized further to carboxyl groups to give carboxy metabolites. As observed from the surveyed cases in this review, hydroxy functionalization leads to loss, attenuation, or retention of pharmacologic activity with respect to the parent drug. On the other hand, carboxy functionalization leads to a loss of activity with the exception of only a few cases in which activity is retained. The exceptions are those groups in which the carboxy functionalization occurs at a position distant from a well-defined primary pharmacophore. Some hydroxy metabolites, which are equiactive with their parent drugs, have been developed into ester prodrugs while carboxy metabolites, which are equiactive to their parent drugs, have been developed into drugs as per se. -
Methyl Substitution Effects on the Proton Chemical Shifts in Benzene *
Methyl Substitution Effects on the Proton Chemical Shifts in Benzene * G. S. REDDY E. I. du Pont de Nemours & Company, Inc. Explosives Department, Eastern Laboratory, Gibbstown, New Jersey, U.S.A. (Z. Naturforschg. 21 a, 609—615 [1966] ; received 16 December 1965) Methyl substitution effects on aromatic and methyl proton chemical shifts in several mono-, di-, and trimethyl benzenes are studied. A new method for obtaining the changes in the ring proton chemical shifts from those of methyl proton shifts at the corresponding positions is used. The extra jr-electron densities in toluene are calculated using the already known relation between the jr-elec- tron densities and the proton shifts in aromatic systems. An inverse relationship is obtained between the ionization potentials and the total methyl effects on the chemical shifts in this series of com- pounds as one would expect. Dipole moment of toluene is calculated, and a reasonably good agree- ment is found between the experimentally observed and the calculated dipole moment. Several efforts have been made from time to Considerable work has also been done in estimat- time to study the substitution effects on chemical ing ir-electron densities from chemical shift meas- shifts and coupling constants. One of the earliest urements in unsaturated systems. This study in- attempts in this line are those of CAVANAUGH and volves extension of the substitution effects and also DAILEY 1 who tried to study the effect of multiple estimating jr-electron densities in methyl benzenes. methyl substitution in methane. They encountered Eight mono-, di-, and trimethyl substituted benzenes negative shifts contrary to expectations based on have been studied, and a new technique has been inductive and hyperconjugative effects of the methyl deployed to obtain the methyl substitution effects group which eventually was attributed to the an- on the chemical shifts of ring protons from proton isotropy effect of the added C — C bonds 2-7. -
Aldehydes and Ketones
12 Aldehydes and Ketones Ethanol from alcoholic beverages is first metabolized to acetaldehyde before being broken down further in the body. The reactivity of the carbonyl group of acetaldehyde allows it to bind to proteins in the body, the products of which lead to tissue damage and organ disease. Inset: A model of acetaldehyde. (Novastock/ Stock Connection/Glow Images) KEY QUESTIONS 12.1 What Are Aldehydes and Ketones? 12.8 What Is Keto–Enol Tautomerism? 12.2 How Are Aldehydes and Ketones Named? 12.9 How Are Aldehydes and Ketones Oxidized? 12.3 What Are the Physical Properties of Aldehydes 12.10 How Are Aldehydes and Ketones Reduced? and Ketones? 12.4 What Is the Most Common Reaction Theme of HOW TO Aldehydes and Ketones? 12.1 How to Predict the Product of a Grignard Reaction 12.5 What Are Grignard Reagents, and How Do They 12.2 How to Determine the Reactants Used to React with Aldehydes and Ketones? Synthesize a Hemiacetal or Acetal 12.6 What Are Hemiacetals and Acetals? 12.7 How Do Aldehydes and Ketones React with CHEMICAL CONNECTIONS Ammonia and Amines? 12A A Green Synthesis of Adipic Acid IN THIS AND several of the following chapters, we study the physical and chemical properties of compounds containing the carbonyl group, C O. Because this group is the functional group of aldehydes, ketones, and carboxylic acids and their derivatives, it is one of the most important functional groups in organic chemistry and in the chemistry of biological systems. The chemical properties of the carbonyl group are straightforward, and an understanding of its characteristic reaction themes leads very quickly to an understanding of a wide variety of organic reactions. -
United States Patent [191 [11] Patent Number: 5,070,175 Tsumura Et Al
United States Patent [191 [11] Patent Number: 5,070,175 Tsumura et al. [45] Date of Patent: Dec. 3, 1991 [54] METHOD FOR THE PREPARATION OF AN Primary Examiner-Morton Foelak ORGANOPOLYSILOXANE CONTAINING Attorney, Agent, or Firm-Millen, White & Zelano TETRAFUNCI'IONAL SILOXANE UNITS [57] ABSTRACT [75] Inventors: Hiroshi Tsumura; Kiyoyuki Mutoh, An ef?cient and economically advantageous method is both of Gunma; Kazushi Satoh, proposed for the preparation of an organopolysiloxane Tokyo; Ken-ichi Isobe, Gunma, all of comprising tetrafunctional siloxane units, i.e. Q units, Japan and, typically, monofunctional siloxy units, i.e. M units, [73] Assignee: Shin-Etsu Chemical Co., Ltd., Tokyo, and useful as a reinforcing agent in silicone rubbers. The Japan method comprises the steps of: mixing the reactants for providing the Q and M units, such as ethyl orthosilicate [21] Appl. No.;. 706,148 and trimethyl methoxy silane, in a desired molar ratio; [22] Filed: May 28, 1991 and heating the mixture at a temperature higher by at least 10° C. than the boiling point of the mixture under [30] Foreign Application Priority Data normal pressure in a closed vessel in the presence of May 29, 1990 [JP] Japan ............ .Q .................. .. 2-l39ll9 water and a catalyst such as a sulfonic acid group-con taining compound. In addition to the greatly shortened [51] Int. 01.5 ............................................ .. C08G 77/06 reaction time and remarkably decreased contents of [52] U.S. c1. ...................................... .. 528/12; 528/10; residual alkoxy groups and gelled matter in the product, 528/21; 528/23; 528/34; 528/36 the method is advantageous also in respect of the ab [58] Field of Search .................... -
Functional Groups Kimberly Hatch Harrison
Functional Groups Kimberly Hatch Harrison Functional groups are those small chemical species you see hanging off the outside of a molecule. Just a handful of these functional groups de- termine most of the chemical reactions that happen between biological molecules. If you memorize the chemical behavior of these functional groups, you’ll be able to predict what kinds of reactions biological molecules can do. You can’t open a lock with a screwdriver–the shape of a screwdriver is quite different from a key, which means it has a dif- ferent function. "Form determines function" is something you’ll hear over and over in biochemistry, and that’s because it’s true. The over- all 3-dimensional shape of a molecule allows it to fit into another molecule, like how a key fits into a lock. But not all keys are the same. You have to look closely at the teeth of a key to see which lock it can open. Similarly, you need to look at the details of the outside of a molecule to understand what kinds of chemical interactions it can do with other molecules. How the carbon skeleton of a biological molecule is folded up de- termines its general 3D shape. So that’s one level of understanding– this molecule looks like a key, this one looks like a lock, etc. But then you must look closer, at the surface details, to understand exactly which key, exactly what kind of lock. When you examine the outside of a biological molecule, you can identify which functional groups are standing out on its surface, like little flags. -
Alkenes and Alkynes
02/21/2019 CHAPTER FOUR Alkenes and Alkynes H N O I Cl C O C O Cl F3C C Cl C Cl Efavirenz Haloprogin (antiviral, AIDS therapeutic) (antifungal, antiseptic) Chapter 4 Table of Content * Unsaturated Hydrocarbons * Introduction and hybridization * Alkenes and Alkynes * Benzene and Phenyl groups * Structure of Alkenes, cis‐trans Isomerism * Nomenclature of Alkenes and Alkynes * Configuration cis/trans, and cis/trans Isomerism * Configuration E/Z * Physical Properties of Hydrocarbons * Acid‐Base Reactions of Hydrocarbons * pka and Hybridizations 1 02/21/2019 Unsaturated Hydrocarbons • Unsaturated Hydrocarbon: A hydrocarbon that contains one or more carbon‐carbon double or triple bonds or benzene‐like rings. – Alkene: contains a carbon‐carbon double bond and has the general formula CnH2n. – Alkyne: contains a carbon‐carbon triple bond and has the general formula CnH2n‐2. Introduction Alkenes ● Hydrocarbons containing C=C ● Old name: olefins • Steroids • Hormones • Biochemical regulators 2 02/21/2019 • Alkynes – Hydrocarbons containing C≡C – Common name: acetylenes Unsaturated Hydrocarbons • Arene: benzene and its derivatives (Ch 9) 3 02/21/2019 Benzene and Phenyl Groups • We do not study benzene and its derivatives until Chapter 9. – However, we show structural formulas of compounds containing a phenyl group before that time. – The phenyl group is not reactive under any of the conditions we describe in chapters 5‐8. Structure of Alkenes • The two carbon atoms of a double bond and the four atoms bonded to them lie in a plane, with bond angles of approximately 120°. 4 02/21/2019 Structure of Alkenes • Figure 4.1 According to the orbital overlap model, a double bond consists of one bond formed by overlap of sp2 hybrid orbitals and one bond formed by overlap of parallel 2p orbitals. -
Reactions of Aromatic Compounds Just Like an Alkene, Benzene Has Clouds of Electrons Above and Below Its Sigma Bond Framework
Reactions of Aromatic Compounds Just like an alkene, benzene has clouds of electrons above and below its sigma bond framework. Although the electrons are in a stable aromatic system, they are still available for reaction with strong electrophiles. This generates a carbocation which is resonance stabilized (but not aromatic). This cation is called a sigma complex because the electrophile is joined to the benzene ring through a new sigma bond. The sigma complex (also called an arenium ion) is not aromatic since it contains an sp3 carbon (which disrupts the required loop of p orbitals). Ch17 Reactions of Aromatic Compounds (landscape).docx Page1 The loss of aromaticity required to form the sigma complex explains the highly endothermic nature of the first step. (That is why we require strong electrophiles for reaction). The sigma complex wishes to regain its aromaticity, and it may do so by either a reversal of the first step (i.e. regenerate the starting material) or by loss of the proton on the sp3 carbon (leading to a substitution product). When a reaction proceeds this way, it is electrophilic aromatic substitution. There are a wide variety of electrophiles that can be introduced into a benzene ring in this way, and so electrophilic aromatic substitution is a very important method for the synthesis of substituted aromatic compounds. Ch17 Reactions of Aromatic Compounds (landscape).docx Page2 Bromination of Benzene Bromination follows the same general mechanism for the electrophilic aromatic substitution (EAS). Bromine itself is not electrophilic enough to react with benzene. But the addition of a strong Lewis acid (electron pair acceptor), such as FeBr3, catalyses the reaction, and leads to the substitution product. -
Transcription 11.12.07
Lab 17A • 12/07/11 [lab quiz] Nomenclature of alkenes The first molecule that I want to look at is this one, where we have the two methyl groups on one side, two hydrogens on the other side. Would it be appropriate to use cis or trans, or E or Z, or both, or neither? One carbon of the double bond versus the other, those are the two different sides of the double, then the top versus the bottom are the two faces of the double bond. If we notice, on both the top face and the bottom face, we have a methyl group that is pointed the same way as a hydrogen. There is a steric factor as far as what alkene would prefer to form thermodynamically, so there is an importance that there’s some interaction there. That methyl group with one hydrogen is exactly the same interaction as you’d have the methyl group and the other hydrogen pointed the opposite way – meaning that if you were to switch the two hydrogens, you’d end up with exactly the same molecule again. The only reason that we use the term cis or trans or E or Z is to describe that it is one configuration versus another, but since there’s only one configuration possible, there’s therefore no term that should be used. It would, in fact, be wrong to call this cis, trans, E, or Z. When an alkene has two of the same substituent on the same side, there is only one unique configuration of that alkene, and so it cannot be called cis, trans, E, or Z. -
Reactions of Alkenes and Alkynes
05 Reactions of Alkenes and Alkynes Polyethylene is the most widely used plastic, making up items such as packing foam, plastic bottles, and plastic utensils (top: © Jon Larson/iStockphoto; middle: GNL Media/Digital Vision/Getty Images, Inc.; bottom: © Lakhesis/iStockphoto). Inset: A model of ethylene. KEY QUESTIONS 5.1 What Are the Characteristic Reactions of Alkenes? 5.8 How Can Alkynes Be Reduced to Alkenes and 5.2 What Is a Reaction Mechanism? Alkanes? 5.3 What Are the Mechanisms of Electrophilic Additions HOW TO to Alkenes? 5.1 How to Draw Mechanisms 5.4 What Are Carbocation Rearrangements? 5.5 What Is Hydroboration–Oxidation of an Alkene? CHEMICAL CONNECTIONS 5.6 How Can an Alkene Be Reduced to an Alkane? 5A Catalytic Cracking and the Importance of Alkenes 5.7 How Can an Acetylide Anion Be Used to Create a New Carbon–Carbon Bond? IN THIS CHAPTER, we begin our systematic study of organic reactions and their mecha- nisms. Reaction mechanisms are step-by-step descriptions of how reactions proceed and are one of the most important unifying concepts in organic chemistry. We use the reactions of alkenes as the vehicle to introduce this concept. 129 130 CHAPTER 5 Reactions of Alkenes and Alkynes 5.1 What Are the Characteristic Reactions of Alkenes? The most characteristic reaction of alkenes is addition to the carbon–carbon double bond in such a way that the pi bond is broken and, in its place, sigma bonds are formed to two new atoms or groups of atoms. Several examples of reactions at the carbon–carbon double bond are shown in Table 5.1, along with the descriptive name(s) associated with each. -
Naming Ethers and Thiols (Naming and Properties)
Ethers • Contain an ─O─ between two carbon groups. • That are simple are named by listing the alkyl names in alphabetical order followed by ether Cyclic ethers (heterocyclic compounds) are often given common names. DO NOT memorize! IUPAC Names for Ethers The shorter alkyl group and the oxygen are named as an alkoxy group attached to the longer hydrocarbon. methoxy propane CH3—O—CH2—CH2—CH3 1 2 3 Numbering the longer alkane gives: 1-methoxypropane Treat all R-O- groups that you find in a molecule as alkoxy groups or branches (substituents), and follow the previous rules we’ve covered for all other families. Properties of Ethers • Slightly polar. • Cannot be H-bond donors. • Are H-bond acceptors (soluble in water up to 4 C’s). • Simple ethers are highly flammable (many form explosive peroxides). Anesthetics • Inhibit pain signals to the brain. • Such as ethyl ether CH3─CH2─O─CH2─CH3 were used for over a century, but caused nausea and were flammable. • Developed by 1960s were nonflammable. Cl F F Cl F H │ │ │ │ │ │ H─C─C─O─C─H H─C─C─O─C─H │ │ │ │ │ │ F F F H F H Ethane(enflurane) Penthrane Methyl tert-butyl ether (MTBE) • Is one of the most produced organic chemicals. • Is a fuel additive used to improve gasoline combustion. • Use is questioned since the discovery that MTBE has contaminated water supplies. Reyes Free to copy for educational purposes Thiols Thiols or mercaptans, are sulfur analogs of alcohols. (The –SH group is called the mercapto, or sulfhydryl group.) The IUPAC nomenclature system adds the ending –thiol to the name of the alkane, but without dropping the final –e.