Malic Acid → Dihexadecyl 2-hydroxybutanedioate

Participants

Reaction Conditions

Reaction Steps

1-Hexadecanol (87.4 g, 0.36 mole), dl-malic acid (20.1 g, 0.15 mole), methanol (600 ml), methane sulfonic acid (15 drops) and several "Chemfluor" boiling chips were placed in a 1000-ml round-bottomed flask. The mixture was refluxed for 16 hours. Most of the methanol was stripped from the mixture at a pressure of about 250 mm Hg. Stripping was then continued at 5 mm Hg and 80° C. for 6 hours. Final weight was 104.41 g. TLC indicated the composition was about 5:3:2 dihexadecyl ester: methyl hexadecyl ester: hexadecanol. Hexane (500 ml) was added and warmed to dissolve all solids. On slow cooling to about 22° C., a first crystalline crop of 38.91 g was obtained after filtration. By further cooling to about 17° C., a second crystalline crop of 27.21 g was obtained. Residuals of 37.81 g were reserved for recycle. Both crystal crops contained considerable impurity; the second crop, about 50%. Recrystallization from hexane gave material which migrated as a single spot during TLC (80:18:2:2 hexane: ethyl acetate:1-butanol: formic acid irrigant, silica gel plates). This recrystallized product melted at 61.4°-62.7° C.

Provenance & Evidence