trans-Cinnamamide → 5,6,7,8-tetrahydro-2-[(E)-2-phenylethenyl]-4H-oxazolo[4,5-d]azepine

関与物質

反応条件

反応手順

A mixture of 4-bromohexahydro-5-oxo-1H-azepine-1-carboxylic acid 1,1-dimethylethyl ester and 3-bromohexahydro-4-oxo-1H-azepine-1-carboxylic acid 1,1-dimethylethyl ester (0.22 g, 0.50 mmol) and trans-cinnamamide (0.06 g, 0.38 mmol) was supported in silica gel (1 g) and mechanically stirred at 120° C. for 3 days. The product was eluted from the silica gel with a 7M solution of ammonia in MeOH and the filtrate evaporated in vacuo. The crude product was basified with a saturated solution of NaHCO3 and extracted with DCM. The organic layer was separated, dried (Na2SO4), filtered and the solvent evaporated in vacuo to yield 5,6,7,8-tetrahydro-2-[(E)-2-phenylethenyl]-4H-oxazolo[4,5-d]azepine (0.045 g, 15% yield, 32% pure) as a brown solid that was used in the next step without further purification. C15H16N2O LCMS: Rt 1.60, m/z 241 [M+H]+ (method 5). The compound 3-bromohexahydro-4-oxo-1H-azepine-1-carboxylic acid 1,1-dimethylethyl ester was not observed in the crude of the reaction.

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