Pyrimidine-5-carboxylic acids

The recorded use of metallo derivatives in the pyrimidine and quinazoline series is minimal. The best described pyrimidinyllithium compounds are those derived from 5-bromopyrimidines. Their reactions are illustrated in the following examples. Pyrimidin-5-yllithium (474 R = H) reacts with solid carbon dioxide under ether to give pyrimidine-5-carboxylic acid (475 R = H) in good yield (65ACS1741) 4,6-dimethoxy- (474 R = OMe),... 

In fact, most pyrimidinecarboxylic acids are made by hydrolysis of the corresponding esters, nitriles or sometimes amides, many of which can be made more easily by primary synthesis than can the acids themselves. Thus, pyrimidine-5-carboxylic acid may be made by alkaline hydrolysis of its ethyl ester (62JOC2264) and pyrimidin-5-ylacetic acid (789 ... 

Pyrimidine-5-carboxylic acid, 4-amino-2-methyl-ethyl ester synthesis, 3, 111... 

In what may be the simplest reaction in this section, a series of pyrimidine-5-carboxylic acids 325 were heated with thionyl chloride to produce 326 (Equation 117) in which a yield is reported only for 326f <1994APH55>. 

Methyl-2-oxo-4-phenyl-l,2,3,4-tetrahydro-pyrimidine-5-carboxylic acid ethyl ester... 

Treatment of arylidenepyruvic acids 236 with 5-amino-3-arylpyrazoles 222 (R is Ar, Ri is H) in most cases was not regioselective and yielded mixtures of several regioisomers and products of their heteroaromatization 2,7-diaryl-4,7-dihydropyrazolo[l,5-tf]pyrimidine-5-carboxylic acids 246 (main product), 3,4-diaryl-4,7-dihydropyrazolo[3,4-Z ]pyridine-6-carboxylic acids 247 and their heteroaromatized derivatives 248 (Scheme 3.68). 

A.3.10 7-(4-Methoxyphenyl)-3-(phenylcarbamoyl)-4, 7-dihydropyrazolo[ 1,5-a]pyrimidine-5-carboxylic acid... 

To study the effect of a solvent on the reductive dethionation, when N-substituted 2-thioxo DHPM derivative 22 (X = S, R = Ph) was treated with Raney-Ni in refluxing acetone, l,4-dihydropyrimidin-5-carboxylic acid 41 (R = Ph) was obtained, while in methanol, l,2,3,4-tetrahydropyrimidin-5-carboxylic acid 42 was formed. In one case, 2-hydroxy-l,2,3,4-tetrahydro-pyrimidin-5-carboxylic acid 43 was obtained (Scheme 18) (86KGS1223). 

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