The ring opening reactions of 3-(2-tetrahydrofuryl) propanol and 3-(2-tetrahyd-rofuryl) propyl chloride by hydrogen chloride were investigated. At first, the effect of the kinds and amount of catalyst, the amount of hydrogen chloride, the reaction temperature and the rate of induction of hydrogen chloride were investigated for obtaining of 1, 4, 7-trichloroheptane as an end product with high yield from 3-(2-tetrahydrofuryl) propyl chloride. This ring opening reaction is an ionic reaction and the catalyst and water were required to proceed the reaction. Amongthe Friedel-Crafts type catalysts, zinc chloride was the best and the ring opening velocity as well as the percentage of yield became higher with more catalyst. The reaction at 120-160°C made the ring opening rate faster but the formation of polychloro ether increased, while the ring opening rate was slow at 70-85°C and the best result was obtained at around 100°C. The presence of 1-2 moles of water in concentrated hydrochloric acid against 1 mole of raw material gave greater ring opening velocity. An initial ring opening reaction with feed of less hydrogen chloride yielded 55-57% 1, 4-dichloroheptanol-7 from the 1-2 cut and 43-45% of 1, 7-dichloroheptanol-4 from 1-5 cut. In the intermediate stage of reaction, there was the formation of a mixture of 75-85% of 1, 4, 7-trichloroheptane and 10-15% of 1, 7-dichloroheptene-3, but in the final stage the yield of 1, 4, 7-trichloroheptane was 95%. Namely, larger part of 1, 4, 7-trichloroheptane was formed from chlori-nation reaction of dichloroheptanol, while 1, 7-dichloroheptene-3 was formed by the intramolecular dehydration reaction of 1, 7-dichloroheptanol-4 and then yielded 1, 4, 7-trichloroheptane easily by addition of hydrogen chloride in the presenc of zinc chloride catalyst. In case of using 3-(2-tetrahydrofuryl)propanol as a starting material, 1, 4, 7-trichloroheptane was obtained in 95% yield by the induction of hydrog enchloride in the presence of zinc chloride catalyst in the absence of water from the beginning.
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