Acetic Acid → tert-butyl(2S)-2-{[2-(1,3-dioxo-1,3-dihydro-2H-isoindol-2-yl)ethyl]amino}-3,3-dimethylbutanoate

Participants

Reaction Conditions

Reaction Steps

A solution of the product of Example 3E (9.34 g, 49.4 mmol) in methanol (33 mL) was treated with L-tert-leucine tert-butyl ester hydrochloride (10 g, 44.9 mmol), sodium cyanoborohydride (5.6 g, 89.8 mmol), and acetic acid (1.5 ml, 26.2 mmol), stirred at 25° C. for 4 hours, and partitioned between chloroform and saturated NaHCO3. The organic phase was washed with brine, dried over MgSO4, filtered and concentrated. The residue was chromatographed on silica gel, eluting with first with 66% chloroform in hexanes and then with 33% ethyl acetate in chloroform to give the title compound (10.5 g, 59% yield).

Provenance & Evidence