Anti-tumour effect of alpha-amino N-substituted-pyrrolidin-2,5-dione-N-mustards on the growth of P388 lymphocytic leukaemia.

(R,S)alpha-[N,N-[bis (2-chloroethyl)]-amino]-N-(o-methoxyphenyl)-pyrrolidin-2,5-dione hydrochloride (I), a new nitrogen mustard incorporated into a 2,5-pyrrolidinedione ring system, was found to be active against P388 lymphocytic leukaemia when administered by i.p., s.c. and p.o. routes. The anti-tumour activity, exhibited by compound (I), against intracerebrally grafted P388 tumour is of interest. However, (R,S)alpha-[N,N-[bis (2-chloroethyl)]-amino]-N-(p-n-butoxyphenyl)-pyrrolidin-2,5-dione dihydrate (II), was found to be active against the P388 tumour following i.p. administration only.