Hydrochloric Acid → Methyl 4-[(2-propynylamino)carbonyl]benzoate

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Reaction Steps

Terephthalic acid mono methyl ester (0.775 g) was dissolved in dry pyridine (10 ml) in a N2 atmosphere. The solution was cooled in an ice-water bath, and thionyl chloride (0.44 ml) was added dropwise. The mixture was warmed to room temperature and was stirred for 1 h to give a pale brown suspension. The mixture was re-cooled in an ice-water bath, and a suspension of proparglyamine hydrochloride (413 mg) in pyridine was added rapidly. The mixture was warmed to room temperature and was stirred for 18 h to give a dark solution. The solvent was evaporated in vacuo to give a dark brown gum, which was dissolved in Ea/hexane/acetic acid (1:1:1% v/v) and flash chromatographed using the same solvent system to give a yellow sludge, which was triturated with ER to give the title compound as a white solid, (0.544 g), m.p. 151.5°-153°.

Provenance & Evidence