The Substitution Reaction between Alkyl Halides and Anion Exchange Resins in Dimethyl Sulfoxide

Abstract

The substitution reaction of alkyl halides with an anion exchange resin (Amberlyst A-26)has been accomplished by a batch procedure under various conditions.
It was found that the halogen atoms of alkyl halides can be readily replaced with the haiide or nitrite group of anion exchange resins in dipolar aprotic solvents such as dimethyl sulfoxide (DMSO) and N, N-dimethylformamide (DMF) at 300C. For example, in the reaction of ethyl, n-pro. pyl and n-butyl iodides with resin of nitrite form in DMSO, the degree of substitution I resin (Ri) was 98.1, 79.4 and 32.5% at 300C for one hour, respectively. ln the reaction of n-alkyl iodides with resin of bromide form in DMSO, the reac tivities were in the order: ethyl n-propyl n-butyl n-pentyl n-octyl. The relative reactivity of nucleophiles (halide groups of resin) for alkyl iodides can be expressed in the ihcreasing order as Fe Cle Bre
When the reaction was carried out by a column procedure, the degree of substihition and yield of product were fpitnd to be similar to those obtained by a batch. procedure.