Method of preparing 1-alkyl-3-carboxy-1H pyrrole-2-acetic acids
AssigneeJanssen Pharmaceutica NV
InventorsRudolf Albert, Albert Willemsens, Guido van der Veken
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Abstract
An improved method of preparing 1-alkyl-3-carboxy-1H-pyrrole-2-acetic acids, the latter compounds being useful intermediates in the preparation of certain anti-inflammatory 1H-pyrrole-2-acetic acids.
Claims8
A process of preparing 1-alkyl-3-carboxy-1H-pyrrole-2-acetic acids having the formula ##STR4## wherein R is a member selected from the group consisting of hydrogen and lower alkyl and alk represents a lower alkyl radical, which process comprises a condensation reaction of 3-oxo-pentanedioic acid with a 1-chloro-2-alkanone of the formula ##STR5## and a lower alkanamine.
A process of preparing 3-carboxy-1,4-dimethyl-1H-pyrrole-2-acetic acid which comprises a condensation reaction of 3-oxo-pentanedioic acid with 1-chloro-2-propanone and methanamine.
A process of preparing a 1-alkyl-3-carboxy-1H-pyrrole-2-acetic acid having the formula:
- ##STR6## wherein R is a member selected from the group consisting of hydrogen and loweralkyl and alk represents a loweralkyl radical, which process comprises:
- (a) slow addition of a loweralkanamine to an aqueous solution of 3-oxo-pentanedioic acid previously cooled to below about 0.degree. C., with continuous cooling of the resulting mixture;
- (b) addition of said mixture of small portions of 1-chloro-2-alkanone of formula ##STR7## with vigorous cooling to maintain the temperature of the reaction mixture below 20.degree. C.;
- and
- (c) stirring the resulting reaction mixture for several hours at a temperature of about 0.degree. C.
Dependencies are inferred from the claim text.