Cyclocondensation Reactions of Heterocyclic Carbonyl Compounds VI Cyclocondensation of the isomeric 1-(2-aminophenyl)-6-azauracil-5-carboxylic acid N-methylderivatives.

摘要

We prepared two isomeric N-methylderivatives of 1-(2-aminophenyl)-6-azauracil-5-carboxylic acid, that means 1-(2aminophenyl)-3-methyl-6-azauracil-5-carboxylic acid 3 and 1-(2-N-methylaminophenyl)-6-azauracil-5-carboxylic acid 8 and studied their cyclocondensation reaction. We found that the cyclization reaction proceeds easily in both cases. Acid 3 afforded 3-oxo-4-methyl-3,4-dihydro-1,2,4-triazino[2,3-a]benzimidozol-2-carboxylic acid 5 while acid 8 afforded its 5-methyl-3,5-dihydro isomer 9. The starting acid 3 was obtained from 1-(2-nitrofenyl)-6-azauracil-5-carbonitrile which arose from the nitroacid 2 while the acid 8 was prepared by coupling 2-(N-methyl-N-acetylamino)-benzendiazonium salt with ethyl cyanoacetylcarbamate which afforded hydrazone 6 which was cyclized to the corresponding 1-aryl-6-azauracil-5-carbonitrile 7. Then this substance 7 was totally hydrolyzed.