Claims
- 1. In a process for preparing a 1-alkyl-1,4-dihydro-4-oxo-7-(4-pyridyl)-3-quinolinecarboxylic acid by (a) reacting a haloprene with a 4-vinylpyridine to form a 4-(4-halocyclohex-3-enyl)pyridine, (b) reacting the 4-(4-halocyclohex-3-enyl)pyridine with hydrochloric acid to form a hydrochloride, (c) aromatizing the resultant 4-(4-halocyclohex-3-enyl)pyridine hydrochloride to a 4-(4-halophenyl)pyridine, (d) nitrating the 4-(4-halophenyl)pyridine, (e) reducing the resultant 4-(4-halo-3-nitrophenyl)pyridine to a 4-(3-aminophenyl)pyridine, (f) converting the 4-(3-aminophenyl)pyridine to an alkyl 1-alkyl-1,4-dihydro-4-oxo-7-(4-pyridyl)-3-quinolinecarboxylate, and (g) hydrolyzing the resultant ester, the improvement which comprises aromatizing the 4-(4-halocyclohex-3-enyl)pyridine hydrochloride by reacting it with 1-5 molar equivalents of a brominating agent at a temperature of 20.degree.-70.degree. C. to add bromine to the double bond of the cyclohexene ring and heating the resultant brominated product at a temperature of 80.degree.-300.degree. C. to form the 4-(4-halophenyl)pyridine.
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of application Ser. No. 715,005, filed Mar. 22, 1985, now U.S. Pat. No. 4,649,202. This application is a continuation-in-part of copending applications Ser. Nos. 511,831, 511,832, and 511,913, all filed July 8, 1983, and now abandoned.
US Referenced Citations (6)
Continuations (1)
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Number |
Date |
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715005 |
Mar 1985 |
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