Bis(4-nitrophenyl) carbonate → tert-butyl (2S,3S)-3-methyl-2-{3-[(2-methyl-1,3-thiazol-4-yl)methyl]-2-oxo-1-imidazolidinyl}pentanoate

Participants

Reaction Conditions

Reaction Steps

A solution containing the product from Example 3G (1.81 g, 7.9 mmol) in a mixture of benzene (8 mL) and methanol (8 mL) was treated with the product from Example 11B (1.0 g, 7.9 mmol), stirred at 50° C. for 1 hour, cooled to 25° C. and treated with sodium borohydride (0.60 g, 15.7 mmol), stirred at 25° C. for 1 hour, quenched with sodium bicarbonate solution and partitioned between ethyl acetate and water. The organic phase was washed with brine, dried over Na2SO4, filtered and concentrated. A solution of the residue (7.9 mmol) in toluene (16 mL) was treated with bis(4-nitrophenyl) carbonate (2.87 g, 9.4 mmol), stirred at reflux for 16 hours, cooled to 25° C. and partitioned between ethyl acetate and 10% K2CO3. The organic phase was washed with brine, dried over Na2SO4, filtered and concentrated. The residue was chromatographed on silica gel eluting with 1% methanol in chloroform to give the title compound (2.0 g, 69% yield).

Provenance & Evidence