Calcium Carbonate → calcium 5-p-chlorobenzoyl-6-chloro-1,2-dihydro-3H-pyrrolo[1,2-a]pyrrole-1-carboxylate

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Reaction Steps

To a solution of 175 mg of 5-p-chlorobenzoyl-6-chloro-1,2-dihydro-3H-pyrrolo[1,2-a]pyrrole-1-carboxylic acid in 5 ml of methanol is added 1 molar equivalent of potassium hydroxide, in the form of a 0.1 N solution, thus yielding a solution containing potassium 5-p-chlorobenzoyl-6-chloro-1,2-dihydro-3H-pyrrolo[1,2-a]pyrrole-1-carboxylate. A solution of 40 mg of calcium carbonate dissolved in the minimum amount of 1 N hydrochloric acid necessary to effect solution of the calcium carbonate, is buffered with 100 mg of solid ammonium chloride, followed by the further addition of 5 ml of water. The thus obtained buffered calcium solution is then added to the solution of potassium 5-p-chlorobenzoyl-6-chloro-1,2-dihydro-3H-pyrrolo[1,2-a]pyrrole-1-carboxylate and the precipitate which forms is collected by filtration, washed with water and air dried to yield calcium 5-p-chlorobenzoyl-6-chloro-1,2-dihydro-3H-pyrrolo[1,2-a]pyrrole-1-carboxylate.

Provenance & Evidence