Synthesis of N-(6-benzylthio-9H-9-purinyl)acetylamino acids

Abstract

1. 6-Mercaptopurine derivatives containing amino acid residues at the nitrogen of the imidazole ring (N-9) were obtained. 2. A single-stage method involving the action of the appropriate N-bromoacetylamino acid esters on 6-benzylmercaptopurine (in dimethyl sulfoxide and in the presence of potassium carbonate) was proposed for the preparation of N-(6-benzylthio-9H-9-purinyl)acetylamino esters. Ethyl and benzyl esters of N-(6-benzylthio-9H-9-purinyl)acetylglycine and the corresponding alanine, valine, leucine, and phenylalanine derivatives (VIII a-e and VIII a1-e1) and also the ethyl esters of N-(6-benzylthio-9H-9-purinyl)acetylsarcolysine (VIII f) and the corresponding L-valine derivatives were obtained. 3. The corresponding N-(6-benzylthio-9H-9-purinyl)acetylamino acids (IX a-f) were obtained from the ethyl esters. 4. N-(6- Benzylthio-9H-9-purinyl)acetylvaline (IX c) and N-(6-benzylthio-9H-9-purinyl)acetylglycine ethyl ester were obtained from 6-benzylmercaptopurine by the multirange method A through the ethyl ester, hydrazide, and azide of 6-benzylthio-9H-9-purinylacetic acid. A by-product of the reaction (6-benzylthio-9H-9-purinylacetic acid) was isolated. 5. The ethyl and benzyl esters of N-bromoacetylglycine and the corresponding alanine, valine, leucine, and phenylalanine compounds and the ethyl esters of N-bromoacetylsarcolysine and the corresponding L-valine compounds were obtained as initial products.