摘要:
1,2-Dichlorobenzene can be prepared by reacting 1,2,4-trichlorobenzene in the gas phase with hydrogen. The reaction is carried out at a temperature from the boiling point of the starting material up to about 400.degree. C. and over a platinum-spinel catalyst.
摘要:
Process for the preparation of an arylglyoxylic acid of the formula Ar--CO--COOH, wherein Ar is optionally substituted aryl, which process comprises oxidizing the corresponding arylethane-1,2-diol of the formula ##STR1## with oxygen or a gas containing molecular oxygen, in an aqueous alkaline medium and in the presence of a platinum-group metal catalyst and, as an activator, a material selected from lead, lead compounds, bismuth and bismuth compounds, at a temperature of up to the boiling point of the reaction mixture; e.g. phenylglyoxylic acid is produced from phenylethane-1,2-glycol preferably using platinum activated with lead, bismuth, or compounds thereof.
摘要:
In a process for the preparation of an aryloxyacetic acid by oxidation of aryloxyethanol of the formula ##STR1## wherein m represents 1 or 2,n represents the numeral which results from the difference (6-m) andR either individually or independently of one another represent hydrogen, alkyl, cycloalkyl, aryl, aralkyl, alkoxy, cycloalkoxy, aryloxy, hydroxyl, halogen, alkylcarbonyl, arylcarbonyl, carboxyl or nitro, or represent a benzene ring or cycloalkane ring fused to the phenyl ring,with oxygen or an oxygen-containing gas in an aqueous alkaline medium at a temperature from 0.degree. C. to the boiling point of the reaction mixture in the presence of platinum metals and/or palladium metals containing catalyst, the improvement which comprises carrying out the oxidation in the additional presence of an activator of lead and/or bismuth and/or a compound thereof and optionally in the additional presence of Cadmium and/or its compounds.
摘要:
Novel process for the preparation of an arylglyoxylic acid compound, e.g., phenylglyoxylic acid, which comprises oxidizing an .alpha.-hydroxyarylacetic acid, e.g., mandelic acid, of the formula ##STR1## in which m is 1, 2 or 3,each R individually is hydrogen, alkyl, cycloalkyl,aryl, aralkyl, alkoxy, cycloakoxy, aryloxy, hydroxyl,halogen, aminoalkyl or carboxyl,with the proviso thattwo R's together can represent the methylenedioxygroup or a fused-on, optionally heterocyclic andoptionally substituted ring,with oxygen or a gas containing molecular oxygen in aqueous alkaline medium in the presence of a catalyst comprising a platinum-group metal in the presence as an activator of at least one of lead, a lead compound, bismuth and a bismuth compound at a temperature of up to the boiling point of the resulting reaction mixture.
摘要:
N,N-Diaryl-ureas of the formulaR.sup.1 --NR.sup.2 --CO--NH--R.sup.3whereinR.sup.1 and R.sup.2 denote aryl andR.sup.3 denotes alkyl, aralkyl or aryl, can be prepared by a process in which a diarylamine of the formulaR.sup.1 --NH--R.sup.2is reacted with an isocyanate of the formulaR.sup.3 --NCOwherein R.sup.1, R.sup.2 and R.sup.34 have the above meaning, in the presence of acid compounds and in the presence or absence of an inert solvent and/or diluent at elevated temperature.
摘要:
Mixtures of 2- and 4-hydroxybenzyl alcohol with high contents of 4-hydroxybenzyl alcohol are obtained by a process comprising reacting phenol and paraformaldehyde in the presence of a strongly basic catalyst and a polyalkylene polyether.
摘要:
Salicylaldehyde and other hydroxybenzaldehydes are prepared by oxydation of a hydroxybenzyl alcohol in the presence of a platinum metal catalyst and lead, silver, tellurium or tin or compounds thereof as activator.
摘要:
In a process for the preparation of 3-phenoxy-benzaldehyde by oxidation of 3-phenoxy-benzyl alcohol of the formula ##STR1## in which m represents a number from 1 to 4,n represents a number from 1 to 5 andR.sup.1 and R.sup.2 are identical or different and denote hydrogen, halogen, alkyl, cycloalkyl, aralkyl, alkoxy, cycloalkoxy, aryloxy or perfluoroalkyl,with an oxygen containing gas in aqueous alkali at a temperature from the solidification point to the boiling point of the reaction mixture in the presence of a platinum metal catalyst and in the presence of lead and/or bismuth and/or tellurium and/or a compound of said lead, bismuth or tellurium.
摘要:
The present invention provides a process for the preparation of an alkylthiomethylphenol or arylthiomethylphenol of the general formula ##STR1## in which m, n, R and R.sup.1 have the meaning mentioned in the specification, in which a hydroxymethylphenol of the general formula ##STR2## is reacted with a mercaptan or thiophenol at a temperature of from 20.degree. to 200.degree. C., if appropriate in the presence of a diluent.
摘要:
Mixtures of 2- and 4-hydroxybenzyl alcohol with high contents of 4-hydroxybenzyl alcohol are obtained by a process comprising reacting phenol with paraformaldehyde in the presence of a compound which exhibits two or more tertiary nitrogen atoms per molecule and a pK.sub.a value of .gtoreq.6.5 (measured at 20.degree. C. in water).