New synthesis of substituted 4-amino-quinazolines and their heteroanaloga

Article abstract of DOI:10.1002/prac.19963380144

N-Chloracetyl-anthranilonitriles react with potassium thiocyanate in the presence of alcohol to the (4-amino-quinazolin-2-yl-thio)-acetic acid ester (5). In the presence of water or primary amine the acetic acid derivative (6) or the acetic acid amide derivatives (7) are obtained. 2,4-Diaminoquinazolines (8) arise if vigorous reaction conditions are employed. With 2-chloracetylamino-cyclopent-1-en-carbonitrile as starting material the pyrimidines (11) are formed from the reaction with potassium thiocyanate. Analogously, (4-pyrimidyl-2-yl-seleno)-acetic acid ester (12) and (thiazolo[4,5-d]pyrimid-2-yl-seleno)-acetic acid derivatives (16) can be prepared with potassium selenocyanate. N-Chloracetyl derivatives of 5-membered heterocycles with enamino-nitrile structure (13, 15, 18, 20) react with potassium thiocyanate to yield thieno[2,3-d]-, thiazolo[4,5-d]-, pyrrolo[2,3-d]-, furo[2,3-d]-and pyrazolo[4,3-d]pyrimidines (14, 16, 19a, 19b, 21). Johann Ambrosius Barth 1996.