Nitrogen → Butylamine

Participants

Reaction Steps

In a 1 I Quickfit flask with a glass-jacketed thermosensor, gas inlet, stainless steel anchor stirrer and heatable (67°-70° C.) pre-column with an attached Claisen bridge and subsequent cold trap, 110 g of N-lauroyl-L-glutamic acid dimethyl ester (LGA-DME) and 100 g of a mixture of cyclohexane derivatives (trimethylcyclohexane, methylethylcyclohexane and diethylcyclohexane in an approximate ratio of 45:25:10) are initially introduced under a gentle stream of N2. 110 g of n-butylamine are metered in over a period of 30 minutes and the mixture is heated under reflux. During the reaction, portions of the methanol liberated during the amidation are separated off, with a little n-butylamine, via the temperature-controlled pre-column. After refluxing for about 8 hours, monitoring by TLC indicates quantitative conversion. The excess n-butylamine is distilled off, first under normal pressure and then in vacuo, and the product is precipitated by addition of acetone. The precipitate formed is filtered off with suction, washed with acetone, dried and comminuted. The target product N-lauroyl-L-glutamic acid di-n-butylamide is obtained in a good yield of about 80% and in excellent purity (LGB 99% (HPLC), nBuNH2 50 ppm (GC), other impurities<1%) in the form of a colorless powder of melting point 150°-152° C.

Provenance & Evidence