Optimization On Synthesis Technology Of O-methallyloxyphenol

Benzofuranol is a chemical name of 2,3-dihydro-2, 2-Dimethyl-7-hydroxybenzof, molecular formula C10H12O2, molecular weight 164, pure colorless or yellow liquid, soluble in methylene chloride, toluene, alcohol, ether and other organic solvents, insoluble in water. Benzofuranol is one of the most important and high value intermediates in the synthesis of various chemical pesticides including carbofuran, carbosulfan, and benfuracarb.O-methallyloxyphenol as the intermediates of benzofuranol compound industry is a colorless transparent liquid with a strong pungent odor. With the characteristics of production of simple, high added value in pesticide production occupies important position. Currently, in the industry mainly use o-methallyloxyphenol as material and xylene as the solvent, aluminum isopropoxide as the catalyst, by translocation and cyclization to get benzofuranol. For the first step of etherification process, the reaction conversion is 99%, but the selectivity is 82% and yield is about 81% by the depth etherification process. When use the depth-etherification process, since the amount of methallylhloride is far more than catechol, inevitably has a large number of methallyl chloride will continue to react with o-methallyloxyphenol,then two hydroxyl-reactive groups reacted affect yield of the target product.For the low selectivity shortcomings of catechol’s depth etherification, this paper attempts to change the reaction condition of etherification process, present a high selectivity and yield production process without significantly increase production costs. Use mixed solvent method and catalytic etherification method respectively to optimize, the mixed solvent method is at the beginning of the reaction under the condition of low conversion rate and high selectivity to stop the reaction. catechol separate by enrichment and water extraction. Then MIBK as solvent reverse extraction catechol from its aqueous solution, using MIBK and MOE as etherification reaction mixed solvent can avoid the MIBK recycling,reuse the catechol and simplify the production process.The catalytic etherification process with methyl isobutyl ketone as solvent, carbonate or bicarbonate as acid-binding agent, KI as catalyst, still use catechol and methallyl chloride as raw materials to produce o-methallyloxyphenol. In the material ratio of PC: MIBK: MAC: Na2CO3: KI is 1.0: 10: 1.2: 0.6: 0.24(molar ratio), maintaining the temperature at 104 ℃, within 90 min dropping methallyl chloride, reacting 12 h, through recycling of raw materials, the whole reaction yield is over 89%, while the selectivity stable at around 94%. At the same time, recovered reaction solvent and catalyst recycling can still achieve good response effect, compared with the current industry results has significantly improved. It can bring great economic benefits significantly reduce industrial waste generation and industrial production pressure on the environment.