Uses of Amines

8 Key excerpts on "Uses of Amines"

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  eBook - PDF

  Chemistry for Today

  General, Organic, and Biochemistry

  • Spencer Seager, Michael Slabaugh, Maren Hansen, , Spencer Seager, Spencer Seager, Michael Slabaugh, Maren Hansen(Authors)
  • 2021(Publication Date)
  • Cengage Learning EMEA

    (Publisher)

  (Section 16.4) 5 Name amines used as neurotransmitters. (Section 16.5) 6 Give uses for specific biological amines. (Section 16.6) 7 Assign IUPAC names for amides. (Section 16.7) 8 Show the formation of hydrogen bonds with amides. (Section 16.8) 9 Give the products of acidic and basic hydrolysis of amides. (Section 16.9) Julien McRoberts/Adobe Stock Photos Copyright 2022 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s). Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it. Amines and Amides 511 THE EFFECTIVENESS of a wide variety of important medicines depends either entirely or partly on the presence of a nitrogen-containing group in their mole- cules. Nitrogen-containing functional groups are found in more medications than any other type of functional group. In this chapter, we will study two important classes of organic nitrogen compounds, the amines and the amides. Both amines and amides are abundant in nature, where they play important roles in the chemistry of life. Our study of these two functional classes will help prepare us for later chapters dealing with amino acids, proteins, and nucleic acids, and provide a basis for understanding the structures and chemistry of a number of medicines. 16.1 Classification of Amines Learning Objective 1 Classify amines as primary, secondary, or tertiary on the basis of given structural formulas. Amines are organic derivatives of ammonia, NH 3 , in which one or more of the hydrogens are replaced by an aromatic or alkyl group (R). Like alcohols, amines are classified as primary, secondary, or tertiary on the basis of molecular structure.

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  Introduction to General, Organic, and Biochemistry

  • Morris Hein, Scott Pattison, Susan Arena, Leo R. Best(Authors)
  • 2014(Publication Date)
  • Wiley

    (Publisher)

  An amine (pronounced ameen) is a substituted ammonia molecule with basic properties and has the general formula RNH 2 , R 2 NH, or R 3 N, where R is an alkyl or an aryl group. Amines are classified as primary (1°), secondary (2°), or tertiary (3°), depending on the number of hydrocarbon groups attached to the nitrogen atom. Some examples include the following: KEY TERM urea KEY TERMS amine heterocyclic compound A Biochemical Perspective: Silk, a natural fiber, is a polyamide composed of amino acids—a protein. During World War II, ladies valued nylon stockings more than gold. The stock of early Remington 22- caliber rifles was very popular and was made of nylon. Instead of urea, uric acid is excreted by birds and reptiles. LEARNING OBJECTIVE LEARNING OBJECTIVE Crops are often fertilized with urea. Lloyd Sutton/Masterfile 25.5 • Amines: Nomenclature and Physical Properties 649 H N H H CH 3 N H H ammonia methylamine (1� amine) N CH 2 CH 3 H CH 3 ethylmethylamine (2� amine) CH 3 CH 2 N CH 2 CH 3 CH 2 CH 3 triethylamine (3 amine) NH 2 aniline (1° amine) NH 2 cyclohexylamine (1° amine) More Practice? Try Paired Exercises 13–16. P R A C T I C E 2 5 . 4 Identify these compounds as 1°, 2°, or 3° amines: (a) CH 3 CH 2 CH 2 NH 2 (e) CH 3 CH 2 NCH 2 CH 3 CH 3 (b) NH 2 CH 3 C CH 3 CH 3 (f) CH 3 CH 2 NHCH 2 CH 3 (c) N H (g) CH 2 NH 2 (d) NH 2 P R A C T I C E 2 5 . 5 Application to Biochemistry The following amines are synthesized by humans: (a) N H CH 2 ¬ CH 2 ¬ NH 2 ¬ (b) CH ¬ CH 2 ¬ NH ¬ CH 3 OH OH HO ¬ “ CH 3 NH 2 ¬ CH ¬ (c) tryptamine epinephrine (adrenaline) alanine C OH O Identify each amine functional group as 1°, 2°, or 3°. Health Connection: Some tertiary amines put a stop to pain The history of local anesthetics traces a path taken in many drug discoveries, that is, starting with a natural molecule that has a desired physiological impact and making it better using organic chemistry. Surprisingly, cocaine, a much-abused narcotic, is also a very good local anesthetic.

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  Organic Chemistry

  • David R. Klein(Author)
  • 2021(Publication Date)
  • Wiley

    (Publisher)

  22.1 Introduction to Amines 1055 DO YOU REMEMBER? Before you go on, be sure you understand the following topics. If necessary, review the suggested sections to prepare for this chapter: • Delocalized and Localized Lone Pairs (Section 2.13) • Brønsted–Lowry Acidity: A Quantitative Perspective (Section 3.3) • Aromatic Heterocycles (Section 17.5) • Activating Groups and Deactivating Groups (Sections 18.7 and 18.8) Take the DO YOU REMEMBER? QUIZ in the online course to check your understanding. 22.1 Introduction to Amines Classification of Amines Amines are derivatives of ammonia in which one or more of the protons have been replaced with alkyl or aryl groups. Amines Ammonia H N H H Primary (1°) H N R H Secondary (2°) R N R H Tertiary (3°) R N R R Amines are classified as primary, secondary, or tertiary, depending on the number of groups attached to the nitrogen atom. Note that these terms have a different meaning than when they were used in naming alcohols. A tertiary alcohol has three groups attached to the α carbon, while a tertiary amine has three groups attached to the nitrogen atom. Amines are abundant in nature. Naturally occurring amines isolated from plants are called alkaloids. Below are examples of several alkaloids that have garnered public awareness as a result of their physiological activity: O OH OH H N Morphine (A potent analgesic isolated from the unripe seeds of the poppy plant Papaver somniferum) N O O O O Cocaine (A potent stimulant isolated from the leaves of the coca plant) Nicotine (An addictive and toxic compound found in tobacco) N N Many amines also play vital roles in neurochemistry (chemistry taking place in the brain).

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  Organic and Biological Chemistry

  • H. Stephen Stoker(Author)
  • 2015(Publication Date)
  • Cengage Learning EMEA

    (Publisher)

  Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s). Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it. 218 CHAPTER 6 Amines and Amides 6-10 Selected Biochemically Important Amines L E A R N I N G F O C U S Be familiar with common heterocyclic amines that have the following functions in the human body: (1) neurotransmitter, (2) central nervous system stimulant, and (3) decongestant. Amines that contain no other functional groups than the amino group are often toxic substances and generally are not prevalent in biological systems. On the other hand, many amines that contain additional functional groups besides the amino group are physiologically active compounds that affect the functioning of the human body. Some are naturally present biosynthesized compounds, others are substances isolated from plants, and still others are laboratory-synthesized products that find use in both prescription and nonprescription drugs. In this section, amines that exert the follow-ing types of effects are considered: (1) neurotransmitters, (2) central nervous system stimulants, and (3) decongestants. Two commonly encountered “core” structures for polyfunctional amines with phys-iological effects are the phenethylamine core and the tryptamine core. These two core structures, both of which are encountered in compounds discussed in this section are: CH 2 CH 2 NH 2 CH 2 CH 2 NH 2 N H Phenethylamine core: Tryptamine core: These two structures differ in the ring structure present [benzene versus indole (Figure 6-8)] and are similar in that an ethylamine group is attached to the ring structure. Neurotransmitters Neurotransmitters are substances present in the human body that assist in passing nerve impulses from one cell to another.

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  Applications

  • Erich Heftmann(Author)
  • 1991(Publication Date)
  • Elsevier Science

    (Publisher)

  8583 Chapter 25 Amines from environmental sources H.A.H. BILLET CONTENTS 25.1 Introduction . . . . . . . . . . . . . . . . . . . 25.2 Methodology . . . . . . . . . . . . . . . . . . . 25.2.1 Gas chromatography . . . . . . . . . . 25.2.2 High-performanceliquid chromatography 25.2.3 Thin-layer chromatography . . . . . . . 25.2.4 Supercritical-fluid chromatography . . . 25.3 Phenylene diamines and diphenylamines . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B583 . . . . . . . . . . . . . 8584 . . . . . . . . . . . . . 8584 . . . . . . . . . . . . . 8586 . . . . . . . . . . . . . 8591 . . . . . . . . . . . . . 8591 . . . . . . . . . . . . . 8591 . . . . . . . . . . . . . 8593 25.1 INTRODUCTION Aliphatic and aromatic mono-, di-, and polyamines are used as raw materials or at an intermediate stage in the production of industrial chemicals, e.g., pharmaceuticals, poly- mers, pesticides, dyestuffs, and corrosion inhibitors. Many of them are suspected of being carcinogenic or mutagenic substances due to their adsorption tendency in tissues. Low- molecular-weight aliphatic amines also receive much attention as odorous substances in studies of air pollution. They can be present or develop through natural decomposition processes in a variety of systems, such as foods, cattle feed yards, and fish industries. Amines can be toxic of themselves, or more often, they can become toxic via chemical reactions, e.g., with nitriles, leading to the formation of nitrosamines. Growing concern about the quality of air, and new evidence for health hazards as a consequence of exposure to amines in low concentrations have stimulated the develop- ment of sensitive analytical techniques, chromatography being an important one. Chromatography of free amines is difficult undoubtedly due to the tendency of these compounds to become adsorbed in the analytical system.

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  eBook - ePub

  Pharmaceutical Chemistry E-Book

  • David G. Watson(Author)
  • 2011(Publication Date)
  • Churchill Livingstone

    (Publisher)

  Chapter 3 Amines David G. Watson Chapter contents Introduction 35 Factors affecting the p Ka value of a base 36 Alkyl groups 36 Electron withdrawing groups 39 Salt formation 48 Reactions of amines in relation to storage and formulation 48 Oxidation 48 Acylation 48 Schiff’s base formation 49 Quaternary amines 52 Introduction The amine group can be considered as the single most important group for conferring pharmacological activity. This is because it is the principle group within organic molecules that bears a positive charge. When it is present in a drug molecule it can exert biological effects through electrostatic interactions with negatively charged groups within proteins and also compete with positively charged cations such as sodium, potassium and calcium ions in biological processes. Amines are derived from ammonia and have the structures shown in Figure 3.1 for mono-, di- and trisubstituted nitrogen. Figure 3.1 Amines. The structures may look planar but, in fact, the structures of amines are more or less tetrahedral, like tetrasubstituted carbon, as shown for trimethylamine in Figure 3.2. In the case of nitrogen, the position that would be occupied by a fourth bond in tetrasubstituted carbon is occupied by a lone pair of electrons. Since nitrogen is less electronegative than oxygen the lone pair within an amine structure is more available than the lone pairs on an oxygen atom to interact with a proton. An approximate measure of the availability of lone pairs of electrons is given by the energy of the highest occupied molecular orbital (HOMO). The deeper the ‘energy well’ that the molecular orbital occupies the less available the electrons are for bond formation with a proton. Thus water has a HOMO of −12.5 eV while ammonia has a HOMO of −10.5 eV, and thus its electrons are more available and it protonates more readily than water

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  Organic Chemistry Study Guide

  Key Concepts, Problems, and Solutions

  • Robert J. Ouellette, J. David Rawn(Authors)
  • 2014(Publication Date)
  • Elsevier

    (Publisher)

  23

  Amines and Amides

  Keys to the Chapter

  23.1 Organic Nitrogen Compounds

  Because nitrogen has five valence shell electrons, it can form three covalent bonds in neutral compounds, leaving one nonbonding electron pair. These bonds can be three single bonds as in amines and amides, one double bond and a single bond in imines, or a triple bond in nitriles.

  Nitrogen is found in many biologically important compounds that have a wide range of physiological properties. However, once a nitrogen-containing functional group is identified, its chemical reactions can often be predicted since the functional groups in these compounds, whose structures are often complex, have the characteristic reactivities of much simpler compounds.

  23.2 Bonding and Structure of Amines

  Amines are pyramidal at the nitrogen atom, with approximately tetrahedral bond angles to all bonded atoms. The nitrogen atom in amines is sp3 hybridized. However, the configuration of an amine is not static. Amines undergo nitrogen inversion to give mixtures of mirror images. The process occurs via a planar transition state. The energy barrier to inversion is low, and nitrogen inversion is rapid so that amines with chiral nitrogen atoms cannot be isolated.

  23.3 Classification and Nomenclature of Amines

  Amines are classified according to the number of alkyl or aryl groups bonded to the nitrogen atom. Primary, secondary, and tertiary amines have 1, 2, and 3 groups bonded, respectively. Amides are classified the same way, with the acyl group counting as one of the carbon groups bonded to the nitrogen atom. Abbreviations for the classes of amines and amides are 1°, 2°, and 3°.

  The common names of simple amines are based on the identity of the alkyl or aryl groups bonded to the nitrogen atom. The names of the alkyl groups are written in alphabetical sequence as one word, followed by the word amine.

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  Principles of Organic Chemistry

  • Robert J. Ouellette, J. David Rawn(Authors)
  • 2015(Publication Date)
  • Elsevier

    (Publisher)

  12

  Amines and Amides

  12.1 Organic Nitrogen Compounds

  For most of this text we have concentrated on the compounds of carbon, hydrogen, and oxygen. We have paid less attention to compounds containing sulfur and nitrogen. Nitrogen is the fourth most common element in living systems after carbon, hydrogen, and oxygen. Organic compounds containing nitrogen are widely distributed in plants and animals and are necessary for life. Nitrogen is present in many vitamins and hormones. Nitrogen is essential in amino acids and proteins, in nucleotides and nucleic acids, and in scores of other cellular molecules. In addition, many nitrogen-containing compounds are important industrial products, including polymers such as nylon, many dyes, explosives, and pharmaceutical agents.

  A nitrogen atom, which has five valence electrons, forms a total of three covalent bonds to carbon or hydrogen atoms in neutral compounds. A nitrogen atom in a functional group can form single, double, or triple bonds. We have discussed these functional groups in previous chapters. In this chapter we will focus on amines and amides, but we will also discuss other functional groups that are either the reactants required to form amines and amides or the products of their reactions.

  Some amines affect the brain, spinal cord, and nervous system. These compounds include the neurotransmitters epinephrine, serotonin, and dopamine (Figure 12.1 ). Epinephrine, commonly called adrenaline, stimulates the conversion of stored glycogen into glucose. Serotonin is a hormone that causes sleep, and serotonin deficiency is responsible for some forms of mental depression. In Parkinson's disease, the dopamine concentration is low.

  Figure 12.1 Structures of Neurotransmitters

  Proteins are made from nitrogen-containing molecules called α-amino acids. In proteins, each amine functional group of one α-amino acid is bonded to the carbonyl carbon of another α-amino acid in a chain of amino acyl groups that contains many amide bonds, or peptide bonds.

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