| 摘要 |
The invention relates to a process for the preparation of 4-steroids of the formula (see formula I) R1 and R2 are independently selected from the group consisting of hydrogen, F, Cl, Br, I, C1-6-alkyl and C1-6-alkoxy, and R4 is selected from the group consisting of hydrogen, (N,N-di-C1-6-alkylamino) methyl, 2-(N,N-di-C1-6-alkylamino)ethyl, C1-6-alkyl, C1-6-alkoxy, phenyl and benzyl, and Q7 represents a carbonyl oxygen atom or is R7-1 and R7-2, wherein one of R7-1 and R7-2 is hydrogen and the other is selected from the group consisting of hydrogen, F, Cl, Br, I, C1-6-alkyl and C1-6-alkoxy, and R9 represents hydrogen or F, and Q11 represents a carbonyl oxygen atom or is R11-1 and R11-2, wherein one of R11-1 and R11-2 is hydrogen and the other is selected from the group consisting of hydrogen, cyano, cyano-C1-3-alkyl, acetoxy, COOH and COO-M+, wherein M+ is Na+, K+ or NH+ ;4, and R16 is selected from the group consisting of hydrogen, cyano, C1-3-alkyl, cyano-C1-3-alkyl, acetoxy, COOH and COO-M+, wherein M+ is Na+, K+ or NH+ ;4, and COOR represents COOH or COO-M+, wherein M+ is Na+, K+ or NH+ ;4. The three step process comprises (i) a haloform reaction of a 17-acetyl steroid converting the acetyl group into a -COOR group, (ii) subsequent ozonolysis of the A-ring and (iii) re-closure of the A-ring by reaction with an appropriate nitrogen compound of formula H2NR 4 to afford a compound of formula I above.
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