Sodium Hydroxide → 2-Tert-butoxycarbonylamino-5-[(3-carboxyphenyl)thio]thiazole

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Reaction Steps

A 1 N aqueous sodium hydroxide solution (50 mL, 50 mmol) was added dropwise to a stirred solution of 2-tert-butoxycarbonylamino-5-[(3-carbomethoxyphenyl)thio]thiazole (1.8 g, (contaminated with bis(tert-butoxycarbonyl)amino adduct)) in a methanol-THF mixture (160 mL, 3:1). The solution was stirred at rt. for 24 h and concentrated. The residue was acidified with 2 N aqueous HCl (30 mL) and the suspension was extracted with dichloromethane-methanol mixture (120 mL, 3:1, 2×). The combined organic extract was dried (MgSO4), filtered and concentrated in vacuo to obtain the titled compound (1.32 g, 75% overall yield from Example 1, part A) as an off-white solid.

Provenance & Evidence