Triethylamine → HCID 14964780, compound

Participants

Reaction Conditions

Reaction Steps

17.2 g of t-butyloxycarbonyl-L-proline were dissolved in 160 ml of tetrahydrofuran, cooled to -20° C and treated with 11.1 ml of triethylamine and 7.7 ml of chloroformic acid ethyl ester. The resulting suspension was stirred at -20° C for a further 5 minutes and treated with a suspension, pre-cooled to -20° C, prepared from 13.4 g of β-alanine methyl ester hydrochloride and 13.4 ml of triethylamine in 160 ml of a mixture of dimethylformamide and tetrahydrofuran (1:1). The mixture was stirred for 1 hour at a temperature below -10° C and for a further hour at room temperature, filtered and the filtrate concentrated in vacuo. The oily residue was dissolved in 200 ml of ethyl acetate and washed three times, each time with 5% potassium hydrogen sulphate solution, water, 5% sodium hydrogen carbonate solution and water, and dried over sodium sulphate. The organic phase was concentrated in vacuo and the oily residue crystallised from ether/petroleum ether. Yield: 19.2 g; melting point 70° C; [α]D25 = -39.2° (c = 1 in dimethylformamide).

Provenance & Evidence