反应详情

A solution of (3-ethoxy-2,6-difluoro-phenyl)-carbamic acid tert-butyl ester (135 g, 0.525 mol) in a mixture of dichloromethane and 10 equivalents trifluoroacetic acid (598 g, 5.25 mol) was stirred at room temperature for 1 hour and concentrated in vacuo. The pH of the residue was adjusted to pH 8 with a saturated aqueous solution of sodium bicarbonate. The organic layer was separated and the aqueous layer is extracted with ethyl acetate (3×250 mL). The organic extracts were combined, washed with a saturated aqueous solution of sodium chloride (2×), dried and concentrated in vacuo. Chromatography of the yellow residual liquid down silica gel using 25:1 hexane:ethyl acetate gave 65 g (66%) of the title compound as oil.

1. concentrationconcentrated in vacuo
2. customThe organic layer was separated
3. extractionthe aqueous layer is extracted with ethyl acetate (3×250 mL)
4. washwashed with a saturated aqueous solution of sodium chloride (2×)
5. customdried
6. concentrationconcentrated in vacuo