Hydrochloric Acid → HCID 69020371, compound

Participants

Reaction Steps

To 1-Benzyl-2-(1-tert-butoxycarbonylamino-2-methyl-propyl)-6-oxo-1,6-dihydro-pyrimidine-5-carboxylic acid ethyl ester (14.22 g from previous step) was added a solution of 4M HCl in 1,4-dioxane (50 mL, 200 mmol) and the reaction was stirred at room temperature for 2.0 h. The reaction was concentrated in vacuo and the residue was dissolved in water and washed with ether. The aqueous layer was basified with 1 N NaOH and extracted into ether. The ether layer was washed with water, dried (Na2SO4), and concentrated to give a crystalline orange solid. This solid (7.08 g, 21.5 mmol) was dissolved in dry CH2Cl2 (100 mL) and to this was added (3-Oxo-propyl)-carbamic acid tert-butyl ester (3.076 g, 17.76 mmol) in dry CH2Cl2 (50 mL) followed by portionwise addition of sodium triacetoxyborohydride (5.65 g, 26.64 mmol). The reaction was stirred for 72 h at room temperature under N2 at which time the reaction was made basic with saturated sodium bicarbonate. The layers were separated, the aqueous layer was extracted with methylene chloride, and the combined organics were washed with brine, dried (Na2SO4), and evaporated to dryness. The residue was purified by flash chromatography on silica gel (1:1 hexanes:EtOAc) to give the title compound as a pale yellow foam (5.59 g 32%, 3 steps). MS(ES+) m/e 487 [M+H]+.

Provenance & Evidence