Triethylamine → Carbamic acid, [2-[hexahydro-4-(3-phenylpropyl)-1H-1,4-diazepin-1-yl]-2-oxoethyl]-, 1,1-dimethylethyl ester

Participants

Reaction Steps

To a suspension of 2.8 g (15.98 mmol.) of N-tert-butoxycarbonyl glycine and 3.67 g (23.96 mmol.) of 1-hydroxybenzotriazole monohydrate was added, at room temperature, 4.6 g (24.0 mmol.) of N-ethyl-N′-3-(N,N-dimethylamino)propylcarbodiimide hydrochloride. The mixture was stirred for one hour. To the reaction system, was added an acetonitrile solution (20 ml) of 5.65 (16.99 mmol.) of 1-(3-phenylpropan-1-yl)-2,3,5,6-tetrahydro-7H-1,4-diazepine dihydrochloride, 5.17 g (33.96 mmol.) of 1,8-diazabicyclo[5.4.0]unde-7-cene (DBU) and 2.3 ml (16.5 mmol.) of triethylamine. The mixture was stirred for 2 hours. The solvent was distilled off under reduced pressure. To the residue was added water, which was subjected to extraction with ethyl acetate. The organic layer was washed with a saturated aqueous solution of sodium hydrogencarbonate and a saturated aqueous saline solution, which was dried over magnesium sulfate, followed by distilling off the solvent under reduced pressure. The crude product thus-obtained was purified by means of a column chromatography (methanol/ethyl acetate 10-20%). The solvent was distilled off under reduced pressure to afford the object compound as a pale yellow oily product. The yield was 5.64 g (94%).

Provenance & Evidence