4-Methylmorpholine → N2-[(benzyloxy)carbonyl]-N1-{(1S,2R)-1-(3,5-difluorobenzyl)-3-[(3-ethylbenzyl)amino]-2-hydroxypropyl)-3-[(1-propylbutyl)sulfonyl]alaninamide

Participants

Reaction Steps

A 250 ml round bottom flask equipped with magnetic stir bar and N2 inlet was charged with 4.0 g (10 mmole) N-[(benzyloxy)carbonyl]-3-[(1-propylbutyl)sulfonyl]alanine and 1.2 g (12 mmole) (2R,3S)-3-amino-4-(3,5-difluorophenyl)-1-[(3-ethylbenzyl)amino]butan-2-ol dihydrochloride in 50 ml anhydrous methylene chloride. To the reaction mixture was added 5.6 ml (51 mmole) NMM, 1.7 g (13 mmole) hydroxybenzotriazole, and lastly 3.1 g (16 mmole) 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride. After stirring at room temperature for 3 hours, HPLC analysis indicated complete reaction. The reaction was diluted with methylene chloride and washed with saturated sodium bicarbonate solution, 0.5 M citric acid, and brine. The organic layer was dried over sodium sulfate, filtered, and concentrated in vacuo to give the N2-[(benzyloxy)carbonyl]-N1-{(1S,2R)-1-(3,5-difluorobenzyl)-3-[(3-ethylbenzyl)amino]-2-hydroxypropyl}-3-[(1-propylbutyl)sulfonyl]alaninamide. A 50 ml round bottom flask equipped with magnetic stir bar and N2 inlet was charged with the crude residue in anhydrous methylene chloride. The reaction was cooled to 0° C. and added 2.5 g (12 mmole) di-tert-butyl dicarbonate and 1.2 ml (11 mmole) N-methyl morpholine. The reaction was allowed to warm to room temperature and stirred for 18 hours at which point HPLC analysis indicated complete reaction. The reaction was diluted with methylene chloride and washed with saturated sodium bicarbonate solution, and brine. The organic layer was dried over sodium sulfate, filtered, and concentrated in vacuo. The crude material was purified on silica gel by flash chromatography using a gradient solvent of 5-40% ethyl acetate in hexane to give 3.4 g of N2-[(benzyloxy-)carbonyl]-N1-{(1S,2R)-N-[(t-butyloxy)carbonyl]-1-(3,5-difluorobenzyl)-3-[(3-ethylbenzyl)amino]-2-hydroxypropyl}-3-[(1-propylbutyl)sulfonyl]-D,L-alaninamide. M+Na=824.

Provenance & Evidence