反应详情

The product of Step 3 (3.0 g, 5.5 mmol) was added to a stirred suspension of phosphorus pentoxide (8 g) in dry methane sulphonic acid (50 ml). After stirring at room temperature for 4 hours the reaction mixture was cautiously poured into a stirred solution of ice cold 50% aqueous sodium hydroxide (final pH 10). The mixture was extracted with chloroform, washed with water and brine, dried and concentrated in vacuo and the residue purified by silica gel chromatography to give the title compound (0.66 g, 32%); MS(ES+) m/e 388 [M+H]+.

1. extractionThe mixture was extracted with chloroform
2. washwashed with water and brine
3. customdried
4. concentrationconcentrated in vacuo
5. customthe residue purified by silica gel chromatography