反应详情

To a solution of 4-phenyl-7-coumarincarboxylic acid from Step 4 (550 mg) and Et3N (560 μL) in THF (25 mL) at 0° C. was added isobutylchloroformate (560 μL) dropwise. After 45 min., NaBH4 (185 mg) in H2O was added and stirring continued for a further 20 min. The mixture was poured onto 1N HCl, extracted 3×Et2O, dried and evaporated. Chromatography on silica gel using hexane/EtOAc 1:1 afforded the title compound as a solid.

1. waitcontinued for a further 20 min
2. extractionextracted 3×Et2O
3. customdried
4. customevaporated