Organic compounds -- part of the class 532-570 series – Organic compounds – Heterocyclic carbon compounds containing a hetero ring...
Patent
1982-07-12
1984-03-06
Chan, Nicky
Organic compounds -- part of the class 532-570 series
Organic compounds
Heterocyclic carbon compounds containing a hetero ring...
C07D33714
Patent
active
044355793
ABSTRACT:
The present invention is concerned with an improved process for the production of highly active optical isomers of (-) 7 or 8 fluorodibenzo[b,f]thiepin-3-carboxylic acid-5-oxide having the structural formula ##STR1## in which the fluoro substituent replaces a hydrogen in the 7 or 8 position. The two active isomers represented by formula II are S(-)7-fluorodibenzo[b,f]thiepin-3-carboxylic acid-5-oxide and R(-)8-fluorodibenzo[b,f]thiepin-3-carboxylic acid-5-oxide. It is especially concerned with the resolution of the racemic 7 or 8 fluorodibenzo[b,f]thiepin-3-carboxylic acid-5-oxide by first forming and separating diastereomers of said racemic carboxylic acids by salt formation with ephedrine followed by crystallization and regeneration of the desired (-) isomers and recycling of the (+) isomer by racemization of the regenerated isomer. The compounds obtained in high yield by this process are highly active prostaglandin antagonists which are useful in treating a variety of conditions such as allergic asthma.
REFERENCES:
patent: 3509154 (1970-04-01), Fouche
patent: 4104280 (1978-08-01), Ackrell
patent: 4237160 (1980-12-01), Hamel et al.
patent: 4334077 (1982-06-01), Belanger et al.
Chemical Abstracts Index Guide, 1977-1981, p. 166 G, "Ephedrine".
Chemical Abstracts Collective Index, 1977-1981, p. 725/CS, "Resolution by [Ephedrine]of . . . ".
Chem. Abstract, 91:190734w.
Belanger Patrice C.
Rokach Joshua
Williams Haydn W. R.
Chan Nicky
Linek Ernest V.
Merck & Co. , Inc.
Pfeiffer Hesna J.
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