Inamixedsolventofaceticacid(AcOH)/water,methylenediphenyldicarbamate(MDC)wassynthesizedbythecondensationofmethylphenylcarbamate(MPC)andformaldehydeinthepresenceofaninorganicacidcatalyst.BasedonthedifferentsolubilitiestoMPCandMDC,themixedsolventshowedhighercatalyticperformancethanpurewater.ThemixedsolventnotonlypromotedthecondensationofMPCbutasloexhibitedtheadvantageoftheproductseparationwiththereactants.Undertheoptimizedconditions:aH_2SO_4massfractionof31%,areactiontemperatureof95℃andreactiontimeof3.5h,theyieldofMDCreached74.3%.Inaddition,therecycleofthesolventwasalsoinvestigated.