tert-Butanol → 1,1-dimethylethyl N-(3,4-dihydro-7-fluoro-2H-1-benzopyran-8-yl)carbamate

Participants

Reaction Steps

A stirred solution of 10.2 grams (0.052 mole) of 3,4-dihydro-7-fluoro-2H-1-benzopyran-8-ylcarboxylic acid, 14.3 grams (0.052 mole) of diphenylphosphoryl azide, and 5.3 grams (0.052 mole) of triethylamine in 150 mL of tert.-butanol was heated at reflux for about 18 hours. The reaction mixture was then concentrated under reduced pressure to a residue, which was subjected to column chromatography on silica gel, with 1:4 ethyl acetate:hexane as the eluant. The product-containing fractions were combined and concentrated under reduced pressure, yielding 6.1 grams of 1,1-dimethylethyl N-(3,4-dihydro-7-fluoro-2H-1-benzopyran-8-yl)carbamate. The NMR spectrum was consistent with the proposed structure.

Provenance & Evidence