3- propanoic acid amide

Pyridyl)propanoic acid amide (C3Hj qON2), L... 

The condensation of a carboxylic acid with ammonia or an amine yields an amide. The amide in Table 15-1 resulted from the condensation of propanoic acid with ammonia. The example in the preceding section involved the condensation of acetic acid with a primary amine. A very important class of biochemical molecules are the amino acids, which join to form protein molecules by the condensation of the amine group of one molecule to the acid group of the next. The amide linkage in this case has the special name peptide. 

Figure 10.10 The synthesis of 2R-methylbutanoic acid, illustrating the use of a chiral auxiliary. The chiral auxiliary is 2S-hydroxymethyltetrahydropyrrole, which is readily prepared from the naturally occurring amino acid proline. The chiral auxiliary is reacted with propanoic acid anhydride to form the corresponding amide. Treatment of the amide with lithium diisopropyla-mide (LDA) forms the corresponding enolate (I). The reaction almost exclusively forms the Z-isomer of the enolate, in which the OLi units are well separated and possibly have the configuration shown. The approach of the ethyl iodide is sterically hindered from the top (by the OLi units or Hs) and so alkylation from the lower side of the molecule is preferred. Electrophilic addition to the appropriate enolate is a widely used method for producing the enantiomers of a-alkyl substituted carboxylic acids...

Replacement nomenclature emphasizes the length of the repeat unit but masks the functionality (i.e., amide) in these units. Alternatively, a repeat unit name (such as, (propanamido)methylidyne), which indicates the functionality but obscures the chain length, may be preferred. The style chosen for the internal (or core or terminal) unit name(s) does not affect the general form of the proposed cascade nomenclature. Thus, the cascade in Figure 3.5 is 36-Cascade tricyclo[3.3.l.l3,7]decane[4-l,3,5,7] (3-oxo-2-aza-propylidyne) (3-oxo-2-azapentylidyne) propanoic acid. 

A reaction which is applicable to the synthesis of imidazoles substituted at C-4 by sulfur substituents is the interaction of a-chloro-a-phenyl thioketones (prepared from the corresponding diazoketones) with ammonia and carboxylic acids. Although the detailed reaction course is yet uncertain, it bears a close resemblance to the reactions of a-chloro ketones with amides. The method has been used to prepare 2-ethyl-4-methyl-5-phenylthioimidazole (145) using ammonia, propanoic acid and 1-chloro-l-phenylthiopropanone (Scheme 82). 

Besides water, another small molecule in the pyrolysate is CO2. This small molecule may be eliminated by various mechanisms including a hydrolysis of the amide groups with the formation of acrylic acid, followed by decarboxylation. Some small peaks In the pyrolysis of polyacrylamide are identical with those from poly(acrylic acid). Even traces of propanoic acid and propenoic acid are present in the acrylamide pyrolysate. A comparison between a time window 25.0 min. to 70 min. from the pyrogram of poly(acrylic acid) and from the pyrogram of polyacrylamide is shown in Figure 6.7.17. 

Catalytic hydrocarboxylations and related esterifications as well as amidations of alkenes belong to a family of carbonylation reactions which has attracted considerable industrial interest. Minor changes in the catalyst system as well as in reaction conditions can lead to simple carboxylic acids, diacids, polyketones, or unsaturated acids as products (Scheme 1). Most importantly, these methods provide routes to monocarboxylic acids, e.g., ethylene to propanoic acid (see Section 2.1.2.2), or 1-olefins (readily available from the oligomerization of ethylene discussed in Section 2.3.1.3) to higher carboxylic acids. 

IH-Pyrrole-l-propanoic acid (3-[pyrrol-l-yl]propionic acid) [89059-06-3] M 139,2, m 59-64", 62,5", pK gt 4,5. RecrystaUise the add from pet ether (b 80-100") and dry it in vacuo. The ethyl ester has b 122°/23mm. The amide forms colourless needles from C6He with m 81" and is soluble in cold H2O. [Clemo Ramage J Chem Soc 49 1931, Jefford Johncock Helv CMm Acta 66 2666 1983.]... 

Esters, amides, and acid hahdes are usually named as derivatives of the parent carboxylic acid. Thus, in Table 4.1, you find ethyl propanoate listed under the parent carboxylic acid, propanoic acid. If you have trouble finding a particular ester under the parent carboxylic acid, try looking under the alcohol part of the name. For example, isopentyl acetate is not listed under acetic acid, as expected, but instead is foimd under the alcohol part of the name (see Table 4.1). Fortunately, this handbook has a Synonym Index that nicely locates isopentyl acetate for you in the main part of the handbook. 

Ammonia is a base, as are amines (see Chapter 6, Section 6.4.1), and carboxylic acids are obviously acids. When mixed together, the expected acid-base reaction occurs to form an ammonium carboxylate. When propanoic acid (17) is mixed with ammonia, ammonium propanoate (95) is formed. Similarly, dime-thylamine (Me2NH) reacts with cyclohexanecarboxylic acid (97) to give dimeth-ylammoniiun cyclohexanecarboxylate (98). Because of this acid-base reaction, mixing an amine or ammonia with an acid (and no other added reagents) at normal temperatures does not give an amide directly. 

Derivatives of propanoic acid. The sessile bond that differentiates acid from acid chloride, acid from amide, and acid from ester, respectively, is shown crossed by a wavy line. 

Figure 9.2. An aldehyde (propanai, CH3CH2CHO), ketone (propanone, acetone, dimethyl ketone, DMK, CH3COCH3) and carboxylic acid (propanoic acid, propionic acid, CH3CH2CO2H). An acid chloride (propanoyi chloride, propionyl chloride, CH3CH2COCI), amide (propanamide, propionamide, CH3CH2CONH2), and ester (ethyl propanoate, ethyl propionate, CH3CH2CO2CH2CH3), typical carboxylic acid derivatives, are also shown.

An approach that was not very successful saw a carbamate isoasparagine derivative (1.236) converted to a nitrile via dehydration of the amide moiety. Removal of the protecting group gave 3-amino-3-cyano-propanoic acid (7.237). This approach was also used to prepare 4-amino-4-cyanobutanoic acid, but the yield of amino acid was again very poor. Introduction of a cyano group in this particular way does not appear to be a good synthetic procedure. 

Conjugate addition of the lithium salt of a chiral amine to a -substituted a, 3-unsaturated ester leads to formation of a chiral, nonracemic amino acid. Addition of the chiral, nonracemic lithium amide 5.143 (contains a phenethyl auxiliary) to 5.142 gave the amino-ester.63 Catalytic hydrogenation removed both benzylic groups (the auxiliary and the benzyl group) and acid hydrolysis of the ester moiety led to 3-amino-3-(4-benzyloxyphenyl)-propanoic acid, 5.144. The initial Michael adduct was formed with >99% dr (dr is diastereomeric ratio), leading to high enantioselectivity in 5.144 after removal of the auxiliary. 

The lUPAC name of the carboxylic acid is propanoic acid the common name is propionic acid. Replacing the oic acid or ic acid ending with amide gives the lUPAC name of propanamide and common name of propionamide. 

Nucleic acids have a chiral center adjacent to the nucleic acid base, which is believed to provide the polymers with stereoregular structures. To confer this feature to the analogues, optically pure a-nucleic acid base substituted propanoic acids were prepared by the conventional optical resolution method. They were coupled with the functional polymers via amide or ester bonds to yield the optically active polymers [4-7]. Functionalization and coupling reactions of nucleobases with the polymers were well summarized in the reviews [2, 3]. 

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