Trifluoroacetic anhydride → HCID 13987794, compound

Participants

Reaction Steps

A mixture of 1.11 g of dimethylsulfoxide and 20 ml of tetrahydrofuran was cooled with dry ice-acetone, and a mixture of 2.24 g of trifluoroacetic anhydride and 3.67 ml of tetrahydrofuran, was gradually dropwise added thereto. The mixture was stirred for 20 minutes, and then a solution obtained by dissolving 0.93 g of 4-chloro-5-[3-(2-n-propyl-4-methoxycarbonylphenoxy)-2-hydroxypropylamino]-2-i-propyl-3(2H)pyridazinone (Compound No. 44) in 8 ml of tetrahydrofuran, was dropwise added thereto. The mixture was stirred for 30 minutes. Then, 1.26 g of triethylamine was dropwise added. Then, the mixture was stirred for 30 minutes under cooling with ice and then for 1 hour at room temperature. Sodium hydrogen carbonate was added thereto, and tetrahydrofuran was distilled off under reduced pressure. The residue was extracted with chloroform, and the extract was washed with water, and dried over sodium sulfate. Then, the solvent was distilled off, and the residue thereby obtained was purified by silica gel column chromatography by using benzene-ethyl acetate (1:1, v/v) as the developer. The solvent was distilled off, and the colorless crystals thereby obtained were further recrystallized from ethyl acetate-ethyl ether to obtain 0.52 g of the above identified compound as colorless crystals having a melting point of 133° C.

Provenance & Evidence