Synthesis of substituted steroidal thiadiazole,triazole and oxidotriazole

摘要

Ethyl-5-cholesten-3beta-O-acetate 2 and its thiosemicarbazide 3 have been synthesized by the reaction of 3beta-hydroxycholest-5-ene 1 with ethyl chloroacetate and 2 with thiosemicarbazide in 1,4 dioxane,respectively.The thiosemicarbazide 3 on chemoselective heterocyclization with cone.H2SO4,conc.NaOH and iodine in the presence of alkali separately afforded 3beta-[5'-amino-1',2',4'-thiadiazole-3'-methoxy]-cholest-5-ene 4,3beta-[5'-mercapto-1',2',4'-triazole-3'-methoxy]-cholest-5-ene 5 and 3beta-[5'-mercapto-3',5'-oxido-1',2',4'-triazolo-3'-methoxy]-5alpha-cholestane 6,respectively.The structures of these compounds have been established on the basis of elemental,analytical and spectral data.