Dichloromethane → HCID 67190457, compound

Participants

Reaction Steps

0.92 g of the methyl ester of 4-(3,4-dihydro-2H-quinoxalin-1-yl)-2-methoxybenzoic acid and 15 ml of dichloromethane are introduced into a three-necked flask equipped with a magnetic stirrer and placed under an inert atmosphere. After cooling to +4° C., 1.92 ml of triethylamine and 0.33 g of triphosgene are successively added. The reaction medium is stirred at ambient temperature for 3 h. 0.64 g of 4-pyrrolidin-3-yl-1H-pyrazole dihydrochloride is then introduced and the mixture is stirred at ambient temperature for 18 h. The reaction medium is washed with a saturated aqueous sodium hydrogencarbonate solution; the organic phase is dried over sodium sulfate and concentrated under reduced pressure. The residue is chromatographed on silica gel eluted with a gradient of methanol from 2% to 4% in dichloromethane. The product obtained is rechromatographed on silica gel eluted with a dichloromethane/methanol 99/1 to 92/8 gradient. 1.06 g of 2-methoxy-4-{4-[3-(1H-pyrazol-4-yl)pyrrolidine-1-carbonyl]-3,4-dihydro-2H-quinoxalin-1-yl}benzoic acid methyl ester are obtained.

Provenance & Evidence