Chemical and pharmacological research on pyran derivatives. VII. Derivatives of naphto/1',2':5,6/pyran/2,3-c/pyrazole and of 12H-naphto/1',2':5,6/pyran/2,3-d/pyrimidine

Reaction of substituted 1-oxo-3-dialkylamino-1H-naphtho[2,1-b]pyrans with N,N-dimethylformamide in the presence of phosphorus oxychloride afforded the corresponding substituted 1-oxo-2-formyl-3-dialkyl-amino-1H-naphtho[2,1-b]pyrans. Condensation of substituted 1-oxo-2-formyl-3-dimethylamino-1H-naphtho[2,1-b]pyrans with hydrazine or monosubstituted hydrazines led to the formation of 11-oxo-8H,11H-naphtho[1',2':5,6]pyrano[2,3-c]pyrazole derivatives through the intermediate hydrazones and subsequent cyclization. Similarly, condensation with acetamidine or guanidine gave rise to the formation of 12-oxo-12H-naphtho[1',2':5,6]pyrano[2,3-d]pyrimidine derivatives. Some of these compounds were tested for their pharmacological properties, but no noteworthy activity was observed.