Lauric Acid → benzyl N-lauroyl-L-alanyl-D-isoglutaminate

Participants

Reaction Conditions

Reaction Steps

Isobutyl chloroformate (2.54 cc) is added to a solution, kept at 0° C., of lauric acid (3.9 g) in anhydrous toluene (156 cc) and triethylamine (2.7 cc). The mixture is stirred for 20 minutes at 0° C. and a solution, cooled to 0° C., of benzyl L-alanyl-D-isoglutaminate hydrochloride (6.7 g) in water (52 cc) and triethylamine (2.7 cc) is then added. The reaction mixture is stirred for 65 hours at a temperature of the order of 20° C. This yields a reaction mixture of gelatinous appearance, to which ethyl acetate (150 cc) is added. The precipitate is filtered off, washed with water (30 cc) and then dried. This yields benzyl N-lauroyl-L-alanyl-D-isoglutaminate (7.6 g) in the form of a white powder. The aqueous phase of the previous filtrate is extracted twice with ethyl acetate (100 cc in total), this ethyl acetate phase is combined with the organic phase of the filtrate and the whole is washed with 0.1 N hydrochloric acid (125 cc) and water (120 cc), dried over magnesium sulphate and then concentrated to dryness under reduced pressure (20 mm Hg) at 50° C. A further amount of benzyl N-lauroyl-L-alanyl-D-isoglutaminate (1.5 g) is obtained. The product (7.6 g and 1.5 g) is recrystallised from methanol (120 cc). This yields benzyl N-lauroyl-L-alanyl-D-isoglutaminate (6.6 g), which melts at 169° C.

Provenance & Evidence