Sulfuric Acid → HCID 13565843, compound

Participants

Reaction Steps

A solution of 2.3 g (4.8 mole) of [[cyclopropyl[6-[4-(ethoxycarbonyl)-1-piperazinyl]-5-fluoro-2-pyridinyl]amino]methylene]propanedioic acid, diethyl ester, in 15 ml of acetic anhydride was treated dropwise with 5 ml of 98% sulfuric acid keeping the temperature 55°-60° C. When the addition was complete, the reaction was stirred for one hour and poured onto 50 g of ice. The aqueous suspension was extracted with chloroform, the chloroform layer washed with water, dried over magnesium sulfate, filtered, and evaporated in vacuo. The residue was triturated with several portions of ethanol/toluene which were also removed in vacuo to give 0.4 g of the title compound, mp 184°-186° C. An additional 0.5 g of product could be obtained by concentrating the original aqueous fraction, mp 184°-186° C.

Provenance & Evidence