A process for the preparation of a compound having the formula Y-O-Ac' ArX--N where Ar is a member selected from the group consisting of (A) phenyl radicals having from one to three substituents selected from the group consisting of halo, lower alkoxy, lower alkyl, lower alkylmercapto, lower alkylsulfonyl, nitro and di(lower alky1)amino, and (B) naph thyl, biphenylyl, fury], pyridyl and thienyl ra