1989 Volume 15 Issue 2 Pages 403-410
The effective treatment of polyethylene glycol as phase transfer catalyst for use in a continuous process was investigated. The third phase (referred to as middle phase) appeared between toluene containing polyethylene glycol (organic phase) and aqueous solution of potassium hydroxide (aqueous phase) by addition of methanol.
No basicity of catalyst (polyethylene glycol with molecular weight 3000) was detected in the organic phase but was detected in the middle phase and most of the catalyst was present in the middle phase. Repeated use of the catalyst was undertaken by use of this phenomenon. The dehydrohalogenation of 2-bromooctane in organic phase by polyethylene glycol was investigated in a batch reactor containing aqueous phase. Only the organic phase containing reaction product was removed from the reactor after the reaction was completed. By adding fresh organic phase containing reactant, the reaction was started again. This procedure was repeated four times to check the amount of loss of catalyst in the repetitions. The results were in good agreement with those calculated without loss of the catalyst.
