PRODUCTION OF ALLYL BROMIDES

PURPOSE:To industrially produce the subject compounds which are intermediates in producing fine chemicals such as agrochemicals, medicines or dyes by carrying out the interchange of halogens in reacting allyl chlorides with a metallic bromide in the presence of a small amount of water and a phase-transfer catalyst. CONSTITUTION:The halogen interchange reaction of allyl chlorides expressed by formula I (R, R1 and R2 are H or lower alkyl) with a metallic bromide (e.g. preferably sodium bromide or potassium bromide) is carried out in the presence of a small amount of water and a phase-transfer catalyst (e.g. preferably tetrabutylammonium bromide) to afford allyl bromides expressed by formula II in a high conversion rate and yield. The water is used in an amount of 0.01-30wt.%, especially 2-15wt.% based on the allyl bromides. For example, allyl chloride, methallyl chloride and gamma-methylallyl chloride are cited as the allyl chlorides expressed by formula I. This method can efficiently be carried out under mild conditions at a high volume efficiency without especially using a solvent. The reactional selectivity is high and the isolation can be carried out simply by performing the operation to separate the resultant liquid product from the water at ambient temperature.