Acids to Amides

Esters are named by replacing the ending -ic acid with the suffix -ate. The alcohol portion of the ester is named by replacing the -ane ending of the parent hydrocarbon name with the suffix -yl. The alkyl radical name of an ester is separated from the carboxylate name, eg, methyl formate for HCOOCH. Amides are named by changing the ending -oic acid to -amide for either systematic or common names, eg, hexanamide and acetamide. 

The use o< HN3 in the conversion of cartxsxyKc acids to amides, of aldehydes mlo intnies, or ol ketones into tetrazoies or amides (with retention). 

Irimescu and Kato have recently described an interesting example of enzymatic KR in ionic liquids instead of organic solvents (Scheme 7.4) [12]. The resolution with CALB is based on the fact that the reaction equilibrium was shifted toward the amide synthesis by the removal of water under reduced pressure. Nonsolvent systems have been also employed in this enantioselective amidation processes, reacting racemic amines with aliphatic acids. The best reaction conditions for the conversion of acids to amides was observed using CALB at 90 °C under vacuum. Meanwhile, no... 

Amination of Free Carboxylic Acids to Amides and Imides... 

Another procedure converts acids to amides. For example, aminolysis of 2 (see p 417) with (S)-l-phenylethanamine yielded 3, the configuration of which (and thus the absolute configuration of 2) was determined by X-ray analysis (see also pp 440 and 477)132,156. 

Bile acids can be modified to many derivatives due to their unique molecular structures, as listed in Table 1. First, we can convert the functional groups at the side-chains from carboxylic acid to amide, alcohol, ester, and so on. Second, we can change the length of the side-chains by decreasing or increasing their methylene number. Third, we can regulate the direction of the hydroxyl groups of the skeletons at the axial or equatorial positions. 

R—C—N— II 1 0 H Amide CH3C—N—H 11 1 0 H ch3ch2cnhch3 0 Acetamide or Ethanamide N-Methylpropan amide -ic or -oic acid to -amide or -carboxylic acid to carboxamide... 

Polymer-bound reagents have also been used. The synthetically important Weinreb amides [RCON(Me)OMe, see 16-82] can be prepared from the carboxylic acid and MeO(Me)NH HCl in the presence of tributylphosphine and 2-pyridine-A -oxide disulfide. Di(2-pyridyl)carbonate has been used in a related reaction that generates amides directly. The reaction of a carboxylic acid and imidazole under microwave irradiation gives the amide. Microwave irradiation of a secondary amine, formic acid, 2-chloro-4,6-dimethoxy[l,3,5]tria-zine, and a catalytic amount of DMAP (4-dimethylaminopyridine) leads to the formamide. ° Ammonium bicarbonate and formamide converts acids to amides with microwave irradiation. Lactams are readily produced from y- or 8-amino acids, for example. 

Single-step conversion of carboxylic acids to amides has been achieved using the A -PSP/BusP reaction system in the presence of amines (equation 17). ... 

Conversion by means of NH3 of carboxylic acids to amides, of aldehydes into nitriles or of ketones into tetrazoles or amides (see 1st edition). 

Conversions of Carboxylic Acids and Derivatives Esters to Acids 250, 395-397 ArC02R -+ ArC02H Amidines to Amides 242 ArN = CHNR2 —> ArNHCHO Acids to Amides 398-401 ArC02H ArCONH2... 

Alcohols can also be reduced, disulphides are reduced to mercaptans, hy-droxamic acids to amides, sulphones to sulphoxides, and chloral to trichlo-roethanol [9]. 

Change the ending of the name from -ic acid or -oic acid to -amide. 

Simple amides are named after the corresponding carboxylic acids by changing the -ic ending (common names) or the -ok ending (lUPAC names) of the acid to -amide. Common names are used more often than lUPAC names. Some examples of the assignment of such names follow ... 

A number of sugars have been alkylated by treatment with methyl iodide and dry silver oxide. The method is also applicable to the esters of hydroxy acids, to amides and to certain other classes of coftipounds. ... 

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