1,1'-Carbonyldiimidazole → tert-Butyl 4-carbamoyl-1,1-dioxo-1,3-thiazolidine-3-carboxylate

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Reaction Steps

Carbonyldiimidazole (520 mg, 3.21 mmol) was added to an ice cold solution of 3-tert-butoxycarbonyl-1,1-dioxo-1,3-thiazolidine-4-carboxylic acid (Example 127 b, 304 mg, 1.15 mmol) in DMF (1 mL). After 5 min. the mixture was warmed to ambient temperature and stirred for 2 h. Gaseous NH3 was bubbled for 10 min through the solution while the temperature was kept below 20° C. Stirring was continued for 12 h at ambient temperature. The reaction mixture was poured into 30 mL ice/water/1N HCl and extracted with EtOAc (2×30 mL). The combined extracts were washed with ice/brine (20 mL), dried over Na2SO4 and concentrated in vacuo to give the title compound (197 mg, 65%) as white solid, MS (ESI) m/e=263.1 [M−H−].

Provenance & Evidence