Triphenylphosphine → Tert-butyl 9-bromo-2,3-dihydrobenzo[F][1,4]oxazepine-4(5H)-carboxylate

Participants

Reaction Conditions

Reaction Steps

A mixture of 1,1-dimethylethyl [(3-bromo-2-hydroxyphenyl)methyl](2-hydroxyethyl)carbamate (Preparation 100) (2.35 g, 6.79 mmol) and triphenylphosphine (1.96 g, 7.47 mmol) in tetrahydrofuran (40 ml) under nitrogen was cooled to 0° C. Diisopropyl azodicarboxylate (DIAD) (1.47 ml, 7.47 mmol) was added dropwise and the resulting mixture stirred for 1 h then concentrated in vacuo. The solvent was removed and the material washed twice with brine, dried (magnesium sulphate) then concentrated in vacuo. Purification of the residue by flash chromatography on silica gel, eluting with 5-25% ethyl acetate in cyclohexane gave the title compound (1.35 g). MS (ES) C14H1879BrNO2 requires 327 found 228 [M+H—COOC(CH3)3]+.

Provenance & Evidence