Study On The Structural Modification Of Steroid-Solasodine

Tumor is one of the most serious diseases which are harmful to human health; natural product has antitumor activity and smaller side effects of treatment. Natural products-steroidal alkaloids-have good improvement of immunity and antitumor activity. In this thesis, the target compound which has the similar structure with solasodine and the important intermediates A1, A2 and A3 used to synthesize this target compound were designed. The synthetic approaches which use 3β-hydroxy-androst-5-en-17-one (10) and 3β-hydroxypregna-5,16-dien-20-one (14) as raw materials to synthesize intermediates la, lb and 2c were studied, and this research focused on the reactions of synthesizing 1b and 2c.During the process of research, Wittig reaction was paid a great attention. Compounds 11, 15,17 and 18 were successfully synthesized by the Wittig reaction between 10,14 and different wittig reagents. The results showed that both raw materials can undergo the Wittig reaction with the simple wittig reagents, and the intermediates which were used to synthesize 1b and 2c were got with the yields of around 50%. Nitazoxanide is an anti-infective drug for treating the certain infection of protozoan and virus. In this thesis,2-hydroxybenzoic acid as the starting materials, its etheride (1) and 2-amino-5-nitrothiazole were performed a amidation with deacid reagent to give 2-hydroxy-N-(5-nitro-2-thiazolyl)-benzamide (2) which is named as Tizoxanide,2 was acetified by acetic anhydride to obtain 2-acetyloxy-N-(5-nitro-2-thiazolyl)-benzamide (3) which is named as Nitazoxanide. The structures of compounds were confirmed by 1H NMR, IR and MS; synthesis mechanisms and major influencing factors were discussed.2 was synthesized by Halogenation reaction and N-acylation reaction with the yield of 55.6%; 3 was synthesized by Halogenation reaction, N-acylation and O-acylation reaction with the yield of 41.6%.