Organic compounds -- part of the class 532-570 series – Organic compounds – Heterocyclic carbon compounds containing a hetero ring...
Reexamination Certificate
2006-08-01
2006-08-01
Aulakh, Charanjit S. (Department: 1625)
Organic compounds -- part of the class 532-570 series
Organic compounds
Heterocyclic carbon compounds containing a hetero ring...
C546S061000
Reexamination Certificate
active
07084274
ABSTRACT:
This invention relates to a method for selectively preparing the 3-oxo-4-aza-5¥á-androstane compound which is used as an intermediate of finasteride by heating 3-oxo-4-aza-5-androstene in a mixture of formic acid and an alkanediol in the presence of zinc.
REFERENCES:
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patent: 5804576 (1998-09-01), Schwartz et al.
patent: WO 02/46207 (2002-06-01), None
J. Templeton et al., “Zinc-Acetic Acid Reduction of the Steroid 4-En-3-one: Novel Conversion of the 4-En-3-one into the 2-En-4-one via a Vinyl Chloride”,J. Chem. Soc., Perkin Trans. 1, vol. 9, 1990, pp. 2581-2584.
P. Xia et al., “Synthesis of N-substituted 3-Oxo-17beta-carboxamide-4-aza-5alpha-androstanes and the Tautomersim of 3-Oxo-4-aza-5-androstenes”,Heterocycles, vol. 47, No. 2, 1998, pp. 703-716.
W. E. Solomons et al. Synthesis and Antimicrobial properties of 17-beta-amino-4-aza-5alpha-androstane Derivatives. J. Pharm. Sci. vol. 63, No. 1, Jan. 1974, pp. 19-23.
Chang Young-Kil
Lee Gwan-Sun
Lee Jae-Cheol
Lee Kyung-Ik
Moon Young-Ho
Aulakh Charanjit S.
Hanmi Pharm. Co. Ltd.
Sughrue & Mion, PLLC
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