摘要:
A process is described for preparing 2,3-dihydro-2,2-dimethylbenzofuran-7-ol (I), which is a useful intermediary in the preparation of Carbofuran, a known multi-functional insecticide.The process consists essentially of reacting the pyrocatechol and a methallylhalide in an inert organic solvent in the presence of a solid inorganic base and a suitable catalyst, to obtain o.methallyloxyphenol with high conversion and high selectivity; this product is thermally transposed to o.methallylpyrocatechol, which is finally cyclized to the product (I) by heterogeneous catalysis in the presence of solid acid catalysts.All stages of the process can be carried out in a single reaction medium, without separating intermediate products.
摘要:
A process for the production of benzofuran derivatives having the general formula, ##STR1## wherein R is alkyl, in particular of 2,3-dihydro-2,2-dimethyl benzofuran-7-ol, starting from pyrocatechol ethers in one step operation.The process essentially consists of heating a solution of pyrocatechol ether in an inert organic solvent in the presence of a catalyst comprising metals of 3.degree. and 4.degree. group of the Periodic System in form of carboxylates or of modified zeolites.The products are known intermediates for the production of insecticides.
摘要:
A process for preparing o-isopropoxyphenol (I) by means of the reaction: ##STR1## in which X is a halogen atom and in which the pyrocatechol (II) is reacted with the isopropyl halide (III) in the presence of an alkaline base in the solid state and of a solid-liquid phase transfer catalyst, in a reaction medium constituted by one or more organic solvents.The catalyst is constituted by a quaternary ammonium or phosphonium salt.The reaction is conducted in a nitrogen atmosphere, at atmospheric pressure, under agitation, at a temperature of preferably between 50.degree. C. and 130.degree. C.
摘要:
Phenols are oxidated to quinones with hydrogen peroxide in the presence of catalytic amounts of bromine, iodine, hydrogen bromide and hydrogen iodide.
摘要:
Mono-ethers of hydroquinones of formula (I) ##STR1## wherein R represents alkyl, alkoxy-alkyl, cycloalkyl, aryl-alkyl, or cycloalkyl-alkyl, andR.sup.1 is hydrogen or alkyl, cycloalkyl, aryl-alkyl, or cycloalkyl-alkyl, are prepared by contacting the corresponding hydroquinones with the corresponding alcohols ROH, in the presence of a catalytic mixture consisting of(a) a strong acid(b) a halogen or a hydrohalic acid selected from HBr, HI, I.sub.2, and Br.sub.2, and(c) H.sub.2 O.sub.2 in a molar amount lower than that of the starting hydroquinone.