反应详情

3-n-Butyl-5-[4-(1,3-dioxol-2-yl)benzyl] hydantoin (5.5 g., 0.017 mole) was dissolved in acetone (150 ml.) and stirred overnight at room temperature with p-toluene sulphonic acid (0.5 g). The acetone was evaporated off in vacuo and the residual oily solid partitioned between water and chloroform. The chloroform phase was washed with sodium carbonate solution (2% W/V), then evaporated in vacuo to give a yellow oil which slowly crystallised and was recrystallised from petroleum ether 60/80° C./ethyl acetate (3/1 V/V) to give 3-n-butyl-5-(4-formylbenzyl) hydantoin, 4.5 g (95%), m.p. 160° C.

1. customThe acetone was evaporated off in vacuo
2. customthe residual oily solid partitioned between water and chloroform
3. washThe chloroform phase was washed with sodium carbonate solution (2% W/V)
4. customevaporated in vacuo
5. customto give a yellow oil which
6. customslowly crystallised
7. customwas recrystallised from petroleum ether 60/80° C./ethyl acetate (3/1 V/V)