Lek Pharmaceuticals D.d.

Lek, Tovarna, Farmacevtskih in Kemicnih . . .

Lek, Tovarna Farmecevtskih in Kemicnih Izdelkov

Borut Furlan

Anton Copar

Zoran Ham

Alenka Jeriha

Marijan Resnik

3-ethyl 5-methyl (+/&#x2212;) 2-[(2-aminoethoxy)methyl]-4-(2-chlorophenyl)-1,4-dihydro-6-methyl-3,5-pyridinedicarboxylate benzenesulfonate, containing overall impurities of significantly less than 0.3% is disclosed, as well as process for its preparation, according to which substance of 3-ethyl 5-methyl (+/&#x2212;) 2-[2-(N-trialkylamino)ethoxymethyl]-4-(2-chlorophenyl)-1,4-dihydro-6-methyl-3,5-pyridinedicarboxylate is converted with benzenesulfonic acid in ethanol solution, at a temperature between 20&#xb0; C. and reflux temperature, followed by isolation and purification of 3-ethyl 5-methyl (+/&#x2212;) 2-[(2-aminoethoxy)methyl]-4-(2-chlorophenyl)-1,4-dihydro-6-methyl-3,5-pyridinedicarboxylate benzenesulfonate. Amlodipine benzenesulfonate is useful as an antiishemic and antihypertensive agent.

High purity amlodipine benzenesulfonate and a process for its preparation

There is disclosed a process for the preparation of 3-ethyl 5-methyl (.+-.) 2-[(2-aminoethoxy)methyl]-4-(2-chlorophenyl)-1,4-dihydro-6-methyl-3,5-pyri dine-dicarboxylate monobenzenesulphonate (amlodipine benzenesulphonate) of formula ##STR1## wherein 3-ethyl 5-methyl (.+-.) 2-[2-(N-tritylamino)-ethoxymethyl]-4-(2-chlorophenyl)-1,4-dihydro-6-methyl -3,5-pyridinecarboxylate is reacted with benzenesulphonic acid in a methanolic or an aqueous methanolic medium at a temperature from 20.degree. C. to the reflux temperature and the title compound is isolated and purified. Amlodipine benzene sulphonate is a valuable anti-ischaemic and anti-hypertensive agent.

Process for the preparation of amlodipine benzenesulphonate

There is disclosed a process for the preparation of 3-ethyl 5-methyl (.+-.) 2-[(2-aminoethoxy)methyl]-4-(2-chlorophenyl)-1,4-dihydro-6-methyl-3,5-pyri dine-dicarboxylate monobenzenesulphonate (amlodipine benzenesulphonate) of formula ##STR1## wherein 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 and the title compound is isolated and purified. Amlodipine benzene sulphonate is a valuable anti-ischaemic and anti-hypertensive agent.

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Ljubljana, Slovenia

Borut Furlan