Methyl acetoacetate → 2-Acetyl-3-benzofurazan-4-yl-acrylic acid methyl ester

Participants

Reaction Conditions

Reaction Steps

Suspended 2,1,3-benzoxadiazole-4-carboxaldehyde (50 g, 0.33 mote) in diisopropyl ether (1300 ml) and added methyl acetoacetate (38 g, 0.32 mole), piperidine (2 g) glacial acetic acid (6 g) in to the suspension one after another. Refluxed the reaction mixture at 70° C. with continuous water separation. Removed sample from the reaction mixture and analysed the samples by qualitative HPLC. Washed the reaction mixture with hydrochloric acid (˜3.5 wt %, 250 ml, sodium bicarbonate solution (˜10 wt %, 250 ml and water (250 ml, 100 ml. Dried the organic layer over sodium sulphate (25 g) and then distilled diisopropyl ether under vacuum to get crude 2-acetyl-3-benzofurazan-4-yl-acrylic acid methyl ester (yield 70 g, HPLC purity 93.4%).

Provenance & Evidence