反应详情

To a solution of 2-benzo[b]thiophenecarbonyl chloride prepared from 2-benzo[b]thiophenecarboxylic acid (356 mg) and oxalyl chloride (0.35 ml) in methylene chloride (2 ml) was added dropwise a mixture of tetraethyl (aminomethylene)bis(phosphonate) (606 mg), pyridine (316 mg) and trace amounts of 4-(dimethylamino)pyridine in methylene chloride (8 ml) at 5° C. The mixture was stirred for 2 hours at ambient temperature followed by the addition of ethyl acetate. The mixture was washed with water, 1N hydrochloric acid, saturated aqueous solution of sodium bicarbonate and brine successively. The organic layer was dried over magnesium sulfate and concentrated under reduced pressure. The residue was treated with diisopropyl ether to give tetraethyl [(2-benzo[b]thiophenecarboxamido)methylene]bis(phosphonate) (790 mg) as a white powder which was recrystallized from a mixture of ethyl acetate and n-hexane.

1. additionwas added dropwise
2. customat 5° C
3. washThe mixture was washed with water, 1N hydrochloric acid, saturated aqueous solution of sodium bicarbonate and brine successively
4. dry with materialThe organic layer was dried over magnesium sulfate
5. concentrationconcentrated under reduced pressure
6. additionThe residue was treated with diisopropyl ether