Hydrochloric Acid → 1-Cyclopropyl-6,7-difluoro-5-methyl-4-oxo-1,4-dihydroquinoline-3-carboxylic acid

Participants

Reaction Steps

20 ml of 90% acetic acid and 5 ml of concentrated hydrochloric acid were added to 1.9 g of ethyl 1-cyclopropyl-6,7-difluoro-5-methyl-1,4-dihydro-4-oxoquinoline-3-carboxylate, followed by refluxing for 2 hours. After cooling, the crystals precipitated were collected by filtration and washed with water, followed by washing with ethanol and then with diethyl ether to give 1.6 g of 1-cyclopropyl-6,7-difluoro-5-methyl-1,4-dihydro-4-oxoquinoline-3-carboxylic acid.

Provenance & Evidence