Low temperature aminolysis of methyl stearate catalyzed by sodium methoxide

Aminolysis of methyl stearate by both primary and secondary amine catalyzed by sodium methoxide was found to be rapid at 30ŶC. under anhydrous conditions. With primary amines under optimum conditions (mole ratio to ester: amine, 10; catalyst, 0.12), the minimum reaction times necessary to obtain yields of amide over 90% were:n-butylamine, 30 min.;iso-butyl-, 1 hour; allyl-, 1.8 hr.; benzyl-, 3.2 hr.;sec-butyl-, 16 hr.; ammonia (a heterogenous reaction requiring an optimum triethylamine to ester ratio of 2 ml./g. and a catalyst mole ratio of 0.20) 2 days. Secondary amines reacted rapidly at 30ŶC. (15 min. to 24 hr. for a 90% yield of amide) when the nitrogen atom was joined into a saturated ring or held at least one methyl group, but very slowly even at 100ŶC, when the substituent was dialkyl larger than methyl. Uncatalyzed, all reactions were extremely slow.