Diethyl (ethoxymethylene)malonate → HCID 13491701, compound

Participants

Reaction Conditions

Reaction Steps

Nine grams of N-ethyl-2-methyl-3-fluoroaniline is allowed to react with 15 g of diethyl ethoxymethylenemalonate under heating at 110° C. for 30 minutes. Then, polyphosphoric acid (obtained from 50 g each of phosphoric acid and phosphorus pentaoxide) is added to be subjected to the reaction at 140° C. for 40 minutes. After the reaction is completed, the mixture is poured into 600 g of water and ice to obtain crystals. The crystals are recovered by filtration, and a 10% sodium hydroxide solution is added to the filtrate and the mixture is refluxed for 1 hour. After refluxing, the reaction mixture is treated with activated carbon and adjusted to pH 2 with concentrated hydrochloric acid, whereby there separate out light yellow crystals. Recrystallization from dimethylformamide yields 10 g of 1-ethyl-7-fluoro-8-methyl-4-oxo-1,4-dihydroquinoline-3-carboxylic acid as the white, needle-like crystals. mp. 245°-246° C.

Provenance & Evidence