1-Hydroxybenzotriazole → Tert-butyl (6'-{[(5-chloropyridin-2-yl)carbonyl]amino}-2',2'-dimethyldispiro[1,3-oxazole-4,4'-chromene-3',3''-oxetan]-2-yl)carbamate

Participants

Reaction Steps

A mixture of tert-butyl (6′-amino-2′,2′-dimethyldispiro[1,3-oxazole-4,4′-chromene-3′,3″-oxetan]-2-yl)carbamate (878 mg, 2.25 mmol), 5-chloro-2-pyridinecarboxylic acid (476 mg, 2.93 mmol), N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride (562 mg, 2.93 mmol), 1-hydroxybenzotriazole (396 mg, 2.93 mmol), N,N-diisopropylethylamine (0.502 mL, 2.93 mmol) and CH2Cl2 (8.78 mL) was stirred for 1.5 hours at ambient temperature. After concentration of the reaction mixture at reduced pressure, the residue was purified with column chromatography on silica gel (hexane-EtOAc, a linear gradient of EtOAc from 0 to 90%) to give tert-butyl (6′-{[(5-chloropyridin-2-yl)carbonyl]amino}-2′,2′-dimethyldispiro[1,3-oxazole-4,4′-chromene-3′,3″-oxetan]-2-yl)carbamate (976 mg).

Provenance & Evidence