Research On By-products Of Benzofuranol

Benzofuranol is the main pesticide intermediates for the synthesis of carbamates derivatives,such as carbofuran,furathiocarb,carbosulfan,benfuracarb and so on.At present,industrialized production of benzofuranol is still using catechol as a raw material.However,these methods were inevitably to generate by-products.Furthermore,these by-products caused a lot of distillation residues after benzofuranol were distilled.Unfortunately,researches focused on benzofuranol by-products were rarely reported both at home and aboard.Under the present benzofuranol manufacturing technique,distillation residue was usually burned directly,which not only wasted a vast amount of recyclable by-product,but also caused environmental pollution.For this reason,this paper mainly studied the by-products in the production of furan phenol.First,several by-products were isolated,purified and characterized,and the by-products' recycling utilization routes were studied.This paper mainly researched on the following three aspects:In Chapter 2,from the distillation residue of benzofuranol,four kinds of by-products were obtained by column chromatography,4-(2-methylallyl)benzene-1,2-diol,4-(2-methyl prop-1-en-1-yl)benzene-1,2-diol,2,2-dimethyl-4-(2-methylprop-1-en-1-yl)-2,3-dihydrobenzo furan-7-ol,2,2,7,7-tetramethyl-2,3,6,7-tetrahydrobenzo[1,2-b:6,5-b']difuran,and these com-pounds were confirmed by 1H NMR and mass spectrometry.Based on the mechanism of benzofuranol cyclization reaction,a series mechanism to explain the formation of 4-(2-methylallyl)benzene-1,2-diol,4-(2-methylprop-1-en-1-yl)benzene-1,2-diol,2,2-dimethyl-4-(2-methylprop-1-en-1-yl)-2,3-dihydrobenzofuran-7-o and 2,2,7,7-tetramethyl-2,3,6,7-tetrahy drobenzo[1,2-b:6,5-b']difuran in benzofuranol synthesis industry were proposed.In Chapter 3,by using 2,2,7,7-tetramethyl-2,3,6,7-tetrahydrobenzo[1,2-b:6,5-b']difuran as the starting materials,three novel benzofuranol derivatives were synthesized via ring opening,Friedel-Craft and nucleophilic reactions.Moreover,the optimal process conditions were researched.In Chapter 4,by using 4-(2-methylallyl)benzene-1,2-diol as the starting materials,vera traldehyde was synthesized via etherification,isomerization and ozonization reactions,and also the optimal process conditions and the formation mechanism were studied;by using 4-(2-methyl allyl)benzene-1,2-diol as the starting materials,4-isobutylbenzene-1,2-diol was synthesized via reactions of catalytic hydrogenation,then the inhibition performance was tested,and the optimal process conditions were explored.