Synthesis of androsteno[17,16-d]pyrazoles and androsteno[17,16-d]-2′-pyrazolines with pyrazolo[3,4-d]pyrimidine fragments

Reactions of pyrazolo[3,4-d]pyrimidine-containing hydrazines with pregnenolone derivatives were studied. The reaction of 16α,17α-epoxy-3β-hydroxy-5-pregnen-20-one and its 3-O-acetyl derivative with 6-hydrazino-3,4-dimethyl-1H-pyrazolo[3,4-d]pyrimidine and 4-hydrazino-3-methyl-6-phenyl-1H-pyrazolo[3,4-d]pyrimidine afforded new androsteno[17,16-d]pyrazoles with pyrazolo[3,4-d]pyrimidine fragments. The reaction of 3β-hydroxypregna-5,16-dien-20-one and its 3-O-acetyl derivative with 4-hydrazino-3-methyl-6-phenyl-1H-pyrazolo[3,4-d]pyrimidine gave hydrazones at position 20 of the pregnenolone molecule, which upon melting undergo cyclization to androsteno[17,16-d]-2′-pyrazolines. Reflux of the hydrazone in mesitylene in the presence of MCPBA leads to a mixture of three products, namely, androsteno[17,16-d]-2′-pyrazoline, androsteno[17,16-d]pyrazole, and dodecahydro-13H-phenanthro[1′,2′:5,6]pyrano[2,3-d]pyrazole derivative resulting from the oxidative expansion of the steroid cyclopentane ring D.