Vanillin → 5(4H)-Oxazolone, 4-[[4-(acetyloxy)-3-methoxyphenyl]methylene]-2-methyl-

Participants

Reaction Conditions

Reaction Steps

152 g (1 mol) of 4-hydroxy-3-methoxy-benzaldehyde, 41 g of sodium acetate, 80 g of N-acetylglycine and 242 g of acetic anhydride are heated together for 30 minutes to 100° C and then for 21/2 hours to the refluxing temperature. The resulting solution is cooled to 0° C and the crystals which have separated out are filtered off and washed with water. The crude 2-methyl-4-(3-methoxy-4-acetoxy-benzylidene)-5(4H)-oxazolone thus obtained is heated to the boil with 1,400 ml of acetone and 545 ml of water for 15 hours under a reflux condenser. Thereafter, the acetone is largely distilled off, whereupon the product crystallises out. After filtration, and washing with acetone, 4-acetoxy-α-acetylamino-3-methoxy-cinnamic acid of melting point 205°-206° C is obtained.

Provenance & Evidence