New steroidal heterocycles: the synthesis and structure of androsteno[2,3-g]-, androstano[3,2-f]-, and androsteno[16,17-g]-pyrazolo[1,5-a]pyrimidines

Abstract

The reaction of 3-aminopyrazole and its 4-cyano-derivative with 2-hydroxymethylene-3-oxo-steroids gave a mixture of angularly fused and linearly fused products, androst-2-eno[2,3-g]- and androstano[3,2-f]-pyrazolo[1,5-a]pyrimidines, respectively. However, the condensation of 3-amino-4-cyano-5-cyanomethylpyrazole with 2-hydroxymethyl-3-oxo-steroids gave only angularly fused products, namely, androst-2-eno[2,3-g]pyrazolo[1,5-a]pyrimidines. The reaction of 3-aminopyrazole and its derivatives with a 2-hydroxymethylene-Δ⁴-3-oxosteroid and 16-hydroxymethylene-17-oxo-steroids also afforded only the angularly fused products, androst-2,4-dieno[2,3-g]- and androst-16-eno[16,17-g]-pyrazolo[1,5-a]pyrimidines, respectively. The structures of all these compounds were established by i.r., u.v., and ¹H and ¹³C n.m.r. spectroscopy.