Amide

6 Key excerpts on "Amide"

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  eBook - PDF

  Introduction to General, Organic, and Biochemistry

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

    (Publisher)

  An Amide (pronounced am-id ) is a functional group consisting of a carbonyl group and a nitrogen atom bonded to the carbon atom, NH 2 C O R The R can be a hydrogen, alkyl, or aryl group. Carboxylic acids react with ammonia to form ammonium salts: OH RC O � NH 3 O � RC O NH 4 � carboxylic acid ammonia ammonium salt OH CH 3 C O � NH 3 O � CH 3 C O NH 4 � acetic acid ammonium acetate Ammonium salts of carboxylic acids are ionic substances. Ammonium acetate, for example, is ionized and exists as ammonium ions and acetate ions, both in the crystalline form and when dissolved in water. When heated, ammonium salts of carboxylic acids lose a molecule of water and are con- verted to Amides: O � C O � H 2 O NH 2 RC O NH 4 � ammonium salt Amide R � O � CH 3 C O NH 4 � ammonium acetate � H 2 O NH 2 CH 3 C O ethanAmide (acetAmide) � Other methods of making Amides start with acyl halides or esters. Amides are neutral (nonbasic) molecular substances; they exist as molecules (not ions) both in the crystalline form and when dissolved in water. An Amide contains the following characteristic structures: N C O H 2 R N C O R¿R– R N C O HR¿ Amide structures R KEY TERM Amide LEARNING OBJECTIVE TABLE 25.1 Why Are Amide and Amine Functional Groups Important to Biochemistry? Answer Comment #1 Amides are the most important functional group in proteins. Amides connect amino acids together to form proteins. #2 Amines allow many hormones and neurotransmitters to be positively charged. Biochemicals gain positive charges when hydrogen ions bond to amines. Lidocaine and carbocaine are Amides used as anesthetics in dental surgery. 25.1 • Amides: Nomenclature and Physical Properties 643 In Amides, the carbon atom of a carbonyl group is bonded directly to a nitrogen atom of an i NH 2 , i NHR, or i NRR group. The Amide structure occurs in numerous substances, including proteins and some synthetic polymers, such as nylon.

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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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  eBook - ePub

  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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  eBook - PDF

  Organic and Biological Chemistry

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

    (Publisher)

  Copyright 2016 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. 226 CHAPTER 6 Amines and Amides The simplest Amide has a hydrogen atom attached to an unsubstituted Amide functional group. O H C NH 2 Next in complexity are Amides in which a methyl group is present. There are two of them, one with the methyl group attached to the carbon atom and the other with the methyl group attached to the nitrogen atom. O NH C NH 2 CH 3 CH 3 O H C and The first of these structures is a 1° Amide, and the second structure is a 2° Amide. ◀ The structure of the simplest aromatic Amide involves a benzene ring to which an unsubstituted Amide functional group is attached. O C NH 2 Cyclic Amide structures are possible. Examples of such structures include N H N H O O N H CH 3 B O N B O Cyclic Amides are called lactams, a term that parallels the use of the term lactones for cyclic esters (Section 5-12). O O NH O A lactone (a cyclic ester) A lactam (a cyclic Amide) A lactam is a cyclic Amide. As with lactones (Section 5-12), the ring size in a lac-tam is indicated using a Greek letter. A lactam with a four-membered ring is a b -lac-tam because the b carbon from the carbonyl group is bonded to the heteroatom (N) of the ring. A lactam with a five-membered ring is a g -lactam because the g -carbon is bonded to the heteroatom (N) of the ring system. NH carbon N O O CH 3 carbon -Lactam -Lactam The members of the penicillin family of antibiotics (Section 10-9) have structures that contain a b -lactam ring.

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  eBook - ePub

  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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  Organic Chemistry

  A Mechanistic Approach

  • Penny Chaloner(Author)
  • 2014(Publication Date)
  • CRC Press

    (Publisher)

  Chapter 22 – Amines, Alkaloids, Amino Acids, Peptides, and Nucleic Acids 1089 (b) N N O O H H H + N N O H OH There are various other solutions involving the other carbonyl group: (c) N N N Me Pr S O O O N N Me OEt H H + N N N Me Pr S O O N N Me OEt OH Key Points from Sections 22.4 and 22.5 • Peptides are formed by the condensation of carboxyl and amino groups in amino acids. Their primary structure is the sequence of amino acids. Secondary structure is deter- mined by the required planarity of the Amide group and interactions between side chains. α-Helices and β-pleated sheets are common motifs. Tertiary structure is the full three-dimensional structure of the peptide. • Peptide synthesis involves a sequence of protection, deprotection, and coupling steps, while the growing peptide is attached to a functionalized polystyrene resin. The process is largely automated. • Classical peptide analysis involves chemical degradation of the peptide to its component amino acids, and specific cleavages of the peptide using chemical reagents or enzymes with predictable selectivities. It is being superseded by instrumental techniques. • Three nucleobases, adenine, guanine, and cytosine, are common to DNA and RNA. Thymine occurs only in DNA and uracil only in RNA. • When attached to a sugar (ribose in RNA, 2-deoxyribose in DNA), the bases are converted to nucleosides. Nucleotide is the term used for phosphorylated nucleosides. • Understanding the hydrogen bonding needed to form the double helix of DNA requires the determination that 2- and 4-hydroxypyridines and their nucleobase analogs exist as the keto tautomer. 1090 Review Problems REVIEW PROBLEMS 1. Give a systematic name for each of the following compounds: (a) NH 2 (b) N (c) NH 2 OH 2. Give a structure for each of the following: (a) N-Methylaniline (b) 4-Aminobenzoic acid (c) 2-Pentylamine 3.

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