Introduction of an N-methyl group in to ethyl N-methylhydantoate causes a fourfold decrease in the rate of base-catalysed exchange of the N-H proton; a second methyl group restores the rate to close to that of the N-unsubstituted hydantoate; the latter effect is observed for N-phenylhydantoates.
将 N-甲基引入 N-甲基
海因酸乙酯会导致 NH 质子的碱催化交换速率降低四倍;第二个甲基使速率恢复到接近 N-未取代的乙内酰
脲的速率;对于 N-苯
海因酸盐观察到后一种效应。