Claims
- 1. A process for the preparation of 3-ethyl 5-methyl (.+-.) 2-[(2-aminoethoxy)methyl]-4-(2-chlorophenyl)-1,4-dihydro-6-methyl-3,5-pyridinedicarboxylate monobenzenesulphonate (amlodipine benzencsulphonate) of formula
- characterized in that 3-ethyl 5-methyl (.+-.) 2-[2-(N-tritylamino)-ethoxymethyl]-4-(2-chlorophenyl)-1,4-dihydro-6-methyl-3,5-pyridinedicarboxylate is reacted with benzenesulphonic acid in a methanolic or an aqueous methanolic medium at a temperature from 20.degree. C. to the reflux temperature.
- 2. The process of claim 1 wherein the title compound is isolated and purified including stirring after completion of the reaction at a temperature below 0.degree. C. to remove tiphenylmethyl methyl ether.
- 3. The process of claim 2 wherein said temperature is about -10.degree. C.
- 4. The process of claim 3 wherein reacting with benzenesulphonic acid is carried out at reflux temperature.
- 5. The process of claim 1 wherein reacting with benzenesulphonic acid is carried out at reflux temperature.
Parent Case Info
This is a divisional application of Ser. No. 08/149,735, filed on Nov. 10, 1993, now U.S. Pat. No. 5,389,654 issued Feb. 14, 1995.
US Referenced Citations (2)
Number |
Name |
Date |
Kind |
4572909 |
Campbell et al. |
Feb 1986 |
|
4879303 |
Davison et al. |
Nov 1989 |
|
Divisions (1)
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Number |
Date |
Country |
Parent |
149735 |
Nov 1993 |
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