- A 3-carbonyl-4-aza-5-androstene -17 β method for preparing derivatives of
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The invention provides a preparation method of a 3-carbonyl-4-aza-5-androstene-17beta derivative. The preparation method comprises the following steps: suspending an A-nor-3,5-cracking-androstan-5-keto-3-carboxylic acid-17beta derivative II in an aqueous solution of ammonium acetate for performing a ring-closure reaction; cooling a reaction product; adjusting the PH value of the reaction product by using industrial ammonia water; filtering the reaction product by spinning; drying the reaction product by spinning; and washing a filter cake by using water, and drying the filter cake to obtain a 3-carbonyl-4-aza-5-androstene-17beta derivative I, wherein R in a formula II and a formula I is carbonyl, carboxylic acid, carboxylic ester, amide, acetyl, hydroxyl, alkyl, ether or chloro. The preparation method has the advantages of mild reaction condition in the absence of inorganic solvents, low requirements on equipment and pre-treatment, complete reaction, and high product purity of over 99 percent without purification; moreover, a spinning-filtered mother solution is recovered, so that the emission of three wastes is reduced greatly; in the whole reaction, used raw materials are readily available; and meanwhile, the reaction yield is high, and the preparation method is economical and environmentally friendly, and is convenient for industrial implementation.
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Paragraph 0028; 0029; 0030; 0040; 0041
(2016/10/31)
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- Process for obtaining 17 beta-(N-tert-butylcarbamoyl)-3-one4-aza-steroids
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17β-(N-tert-butylcarbamoyl)-3-one-4-aza-steroids (I) can be obtained by a process which comprises the reaction of 17β-(alkoxycarbonyl)-3-one-4-aza-steroid with lithium tert-butylamide in an organic solvent. Some compounds of formula (I), for example, finasteride, are useful as inhibitors of 5α-reductase, and can be used in the treatment of benign prostatic hyperplasia and alopecia.
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- Synthesis of N-substituted 3-oxo-17β -carboxamide-4-aza-5α-androstanes and the tautomerism of 3-oxo-4-aza-5-androstenes
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An N-aryl-3-oxo-4-aza-5α -androst-1-ene-17β carboxamide and three N-aryl or alkyl substituted 17α -hydroxy-3-oxo-4-aza-5α -androstane-17β -carboxamides were synthesized as antiandrogen candidates from 3-oxoandrost-4-ene-17β - carboxylic acid and androst-4-ene-3,17-dione respectively. The chemo- and stereoselective reduction of 3-oxo-4-aza-5-ene intermediates with formic acid and their tautomerism in a solution of chloroform and methanol were described.
- Xia, Peng,Yang, Zheng-Yu,Xia, Yi,Zhang, Hao-Bing,Zhang, Ke-Hua,Sun, Xun,Chen, Ying,Zheng, Yun-Qing
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p. 703 - 716
(2007/10/03)
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