Process for preparing piperidinyl benzimidazoles
AssigneeMerrell Dow Pharmaceuticals Inc.
InventorJohn M. Kane
Life of this patent
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Abstract
The present invention is directed to a new class of piperidinyl benzimidazole antihistamines which can be described by the following formula: ##STR1## wherein Y is represented by CO or CHOH; m is an integer from 1 to 2; R is represented by C.sub.1-4 alkyl, C.sub.1-4 alkoxy, halogen, hydroxy and hydrogen; X is represented by hydrogen, COOR.sub.2, in which R.sub.2 is represented by a C.sub.1-4 alkyl, or an alkylene phenyl radical of the formula: ##STR2## wherein T is represented by CHOH, CO, O, or a direct bond; R.sub.1 is represented by C.sub.1-4 alkyl, C.sub.1-4 alkoxy, halogen, hydroxy, 2,2-dimethyl ethanoic acid and hydrogen; n is an integer from 1 to 5; and the pharmaceutically acceptable acid addition salts thereof.
Claims7
A process for producing a piperidinyl benzimidazole of the formula:
- ##STR20## wherein Y is represented by CO;
- R is represented by C.sub.1-4 alkyl, C.sub.1-4 alkoxy, halogen, hydroxy and hydrogen, X is COOR.sub.2 in which R.sub.2 is represented by a C.sub.1-4 alkyl, or X is an alkylene phenyl radical of the formula:
- ##STR21## wherein T is represented by O, or a direct bond;
- R.sub.1 is represented by C.sub.1-4 alkyl, C.sub.1-4 alkoxy, halogen, hydroxy, 2,2-dimethyl ethanoic acid and hydrogen;
- n is an integer from 1 to 5;
- or a pharmaceutically acceptable acid addition salt thereof;
- comprising:
- carrying out an acylation reaction between:
- a) a benzimidazole of the formula ##STR22## wherein R is as defined above, and;
- b) a piperidinyl derivative of the formula:
- ##STR23## wherein X is as defined above and E is a C.sub.1-4 alkyl;
- c) in the presence of n-butyl lithium.
Dependencies are inferred from the claim text.