3-methyl-1,3-thiazolidine-4-carboxylic acid

Conditions: temp:80.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: L-thiazolidine-4-carboxylic acid (13.3 g) in a mixture of 37% formaldehyde (22.5 ml) and 96% formic acid (39.3 ml) was heated to 80° C. After one hour CO2 evolution ceased. The heating was continued until most of the solvent was removed. The residue was dissolved in methanol and evaporated on the rotovap three times. One equivalent of concentrated hydrochloric acid was added and the resulting salt crystallized from methanol and ethyl ether. Yield 17.0 g (92%). was removed The residue was dissolved in methanol evaporated on the rotovap three times the resulting salt crystallized from methanol and ethyl ether