反应详情

To a solution of propargyl bromide (1.51 ml, 20 mmol) in dichloromethane (15 ml) and aqueous sodium hyopchlorite (22.4 ml, 10%, 30 mmol) at 0° C. was added dropwise with stirring benzaldoxime (2.42 g, 20 mmol) in dichloromethane (15 ml). When addition was complete the ice bath was removed and the reaction stirred for a further 2 h. The organic layer was separated and the aqueous layer washed with dichloromethane (2×20 ml) then the combined organic layers dried (MgSO4). Solvent removal under reduced pressure gave a solid which was recrystallised from 40°-60° C. petroleum ether fraction to give the desired isoxazole (2.64 g, 11.1 mmol, 55%); mp 82°-3° C., δH (CDCl3) 4.40 (2H, s, CH2 --Br), 6.50 (1H, s, CH-4), 7.3-7.9 (5H, m, C6H5).

1. additionWhen addition
2. customwas removed
3. customThe organic layer was separated
4. washthe aqueous layer washed with dichloromethane (2×20 ml)
5. dry with materialthe combined organic layers dried (MgSO4)
6. customSolvent removal under reduced pressure
7. customgave a solid which
8. customwas recrystallised from 40°-60° C. petroleum ether fraction