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US 4,283,336 AGranted
Process for the preparation of 3-amino-2-(5-fluoro and 5-methoxy-1H-indol-3-yl)propanoic acid derivatives
AssigneeMiles Laboratories, Inc.
InventorsRobert N. Schut, Max E. Safdy, Enrique Hong
Life of this patent
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Abstract
The compounds having Formula I, ##STR1## wherein X is a fluorine or methoxy group, and R is a hydrogen or methyl group, such that R is hydrogen only when X is fluorine are novel. The compounds having Formula I and their acid addition salts are useful for the treatment of hypertension. Processes for the preparation of the compounds having Formula I and useful intermediates are described.
Claims5
A process for preparing a compound having Formula I ##STR16## wherein R is a hydrogen atom or a methyl group and X is fluorine or a methoxy group, comprising the steps of:
- (a) reacting a compound having Formula II ##STR17## wherein X is fluorine or a methoxy group, with an alkali metal base selected from the group of sodium metal, lithium hydride, sodium ethoxide or potassium t-butoxide and an acyloxylating agent selected from the group of diethyl carbonate, dimethyl carbonate, dibenzyl carbonate, ethyl chloroformate or methyl chloroformate in a suitable solvent at a temperature in the range of from about 0.degree. to 110.degree. C. to produce a compound having Formula III ##STR18## wherein X is as above and R.sub.1 is a lower alkyl group of from 1 to 3 carbon atoms or a phenyl group;
- (b) separating compound III from the reaction mass;
- (c) hydrogenating the compound having Formula III under pressure, in the presence of a catalyst, in a suitable solvent selected from the group of acetyl chloride, acetic anhydride, propionyl chloride or benzoyl chloride to produce a compound having Formula IV, ##STR19## wherein R.sub.1 and X are as defined above and R.sub.2 is methyl, ethyl or phenyl;
- (d) separating Compound IV from the reaction mass;
- (e) hydrolyzing the compound having Formula IV with an aqueous alkali metal hydroxide at a concentration from about 3 N to 10 N for about 1 to 15 hours, at a temperature of from about 50.degree. C. to 100.degree. C. to produce a compound having Formula V, ##STR20## wherein M.sup.+ is an alkali metal cation and X is as defined above;
- (f) decarboxylating the compound having Formula V with an aqueous acid at a temperature from about 50.degree. C. to 100.degree. C. and isolating the compound having Formula I wherein R is a hydrogen atom and X is as defined above, and
- (g) optionally esterifying the compound having Formula I, wherein R is a hydrogen atom and X is as defined above, with methanol in the presence of an acid catalyst to produce the compound having Formula I wherein R is a methoxy group and X is as defined above.
4 more elements
Dependencies are inferred from the claim text.