Sulfuric Acid → 4-Methoxy cinnamic acid

Participants

Reaction Steps

Anisidine (12.3 g) was dissolved in 30 ml acetic acid and 25 ml water and cooled to 10° C. 98% Sulfuric acid (10 ml) was added with cooling. Sodium nitrite (6.9 g in 20 ml water) was then added at 0°-2° C. over 1 hour with stirring. t-Butylamine (0.05 g) was then added and after 10 minutes, Pd(dba)2 (1.0 g) and 0.07 g of 1,2-bis(diphenylphosphino)ethane (diphos) in 50 ml ethyl acetate were added. Acrylic acid (10.3 ml) was then added slowly over 10 minutes. The reaction mixture was allowed to warm to room temperature. After 22 hours under nitrogen, the mixture was neutralized with 30% sodium hydroxide solution (33 g) diluted with 500 ml water. The aqueous solution was separated, neutralized with 10% sulfuric acid to give 12 g of p-methoxycinnamic acid as a solid precipitate which was filtered off (m.p. 165°-170° C.) (67.4% yield).

Provenance & Evidence