2-Butynedioic acid → HCID 54409709, compound

Participants

Reaction Steps

A mixture of acetylenedicarboxylic acid (6.6 g, 55 mmoles) and N,N'-bis(3,4-dichlorophenyl)thiourea (20.0 g, 55 mmoles) in methanol (400 mls) is stirred at room temperature for 16 hours. The suspended solid is filtered off and rinsed with cold methanol. The solid is then rinsed repeatedly with boiling CH2Cl2 and filtered off. The combined dichloromethane filtrates are concentrated and cooled to afford the crystalline product (7.6 g), mp 221°-222° C.

Provenance & Evidence