反应详情

To a solution of 3-bromo-5-(tert-butyl-dimethyl-silanyloxymethyl)-thiophene-2-carbaldehyde [30.1 g, 89.7 mmol, Intermediate (68)] in ethanol (350 mL) was added benzophenone hydrazone (20 g, 104.7 mmol). The resulting yellow solution was stirred at reflux for 6 hours. The solvent was then removed and the residue was chromatographed through silica gel (n-heptane/dichloromethane, 20/80 as eluant) to produce N-benzhydrylidene-N′-[1-[3-bromo-5-(tert-butyl-dimethyl-silanyloxymethyl)-thiophen-2-yl]-methylidene]-hydrazine [41.3 g, Intermediate (69)]. LC/MS: 515.1 (M+H), (2 isomers detected) RT=4.17 minutes and 4.34 minutes.

1. temperatureat reflux for 6 hours
2. customThe solvent was then removed
3. customthe residue was chromatographed through silica gel (n-heptane/dichloromethane, 20/80 as eluant)