tert-butyl N-(2-oxoethyl)carbamate → HCID 86614262, compound

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Reaction Steps

0.24 g of the N-[8-(4-chloro-D-phenylalanyl)-8-azabicyclo[3.2.1]oct-3-yl]-N-cyclohexyl-N′,N′-diethylurea endo compound, obtained in step 1.5, is dissolved in 5 ml of dichloromethane under N2 in the presence of 0.10 g of tert-butyl N-(2-oxoethyl)carbamate and of 0.22 g of sodium triacetoxyborohydride. The reaction medium is stirred at ambient temperature for 16 h. After evaporation to dryness, 0.05 g of tert-butyl N-(2-oxoethyl)carbamate and 0.1 g of sodium triacetoxyborohydride are added, and stirring is maintained for 3 days. After the addition of 1 ml of methanol and 4 g of Dowex® 50X2 resin, the mixture is stirred for 1 h 30 min. After filtration and washing of the resin with tetrahydrofuran and methanol, the expected compound is released by adding a 1N solution of aqueous ammonia in methanol. The methanol is evaporated off, to give 0.14 g of tert-butyl (2-{[(1R)-1-(4-chlorobenzyl)-2-(3-{cyclohexyl[(diethylamino)carbonyl]amino}-8-azabicyclo[3.2.1]oct-8-yl)-2-oxoethyl]amino}ethyl)carbamate.

Provenance & Evidence