摘要:
Process for the preparation of alkyl aryl ethers containing carboxyl groups which are suitable for the preparation of colour film couplers, or derivatives thereof, by reaction of aromatic alcohols with alkyl halides containing carboxyl groups or derivatives thereof and basic alkali metal or alkaline earth metal compounds, characterized in that the reaction is carried out in the melt of the aromatic alcohol.
摘要:
The invention concerns 4,6-diamino-resorcinol which is prepared in the form of its dihydrochloride by catalytic hydrogenation of 1,3-benzyloxy-4,6-dinitrobenzene on a noble metal contact in a two-phase mixture of dilute aqueous hydrochloric acid and an organic solvent which is not miscible with dilute aqueous hydrochloric acid. This process is carried out at a pressure of between 1 and 200 bar and a temperature of between 0 and 200.degree. C.
摘要:
Process for preparing haloaromatic amines by catalytic hydrogenation of the corresponding halonitroaromatic compounds, characterized in that iron-containing Raney nickel is used as catalyst, where the haloaromatic amines prepared can be used for the synthesis of photographic couplers which are useful in photographic emulsions or elements.
摘要:
4,6-diaminoresorcinol can be prepared in a plurality of steps in such a way thata) 1,3-dichlorobenzene is nitrated with a mixed acid of HNO.sub.3, H.sub.2 SO.sub.4 and SO.sub.3 at 0 to 40.degree. C. in anhydrous H.sub.2 SO.sub.4,b) the resulting 1,3-dichloro-4,6/2,4-dinitrobenzene isomeric mixture is first reacted with benzyl alcohol in the presence of a strong base at -15.degree. C. to +15.degree. C. and then at 20.degree. to 40.degree. C. to give the dibenzyloxy compound andc) the 1,3-dibenzyloxy-4,6-dinitrobenzene isomer arising in pure form in b) is converted to the 4,6-diaminoresorcinol by catalytic hydrogenation.
摘要翻译:可以以多个步骤制备4,6-二氨基间苯二酚,使得a)在无水H 2 SO 4中在0至40℃下用HNO 3,H 2 SO 4和SO 3的混合酸硝化1,3-二氯苯,b) 所得的1,3-二氯-4,6 / 2,4-二硝基苯异构体混合物首先在强碱存在下在-15℃至+ 15℃下与苄醇反应,然后在20℃至 40℃,得到二苄氧基化合物,和c)在b)中以纯形式产生的1,3-二苄氧基-4,6-二硝基苯异构体通过催化氢化转化为4,6-二氨基间苯二酚。
摘要:
Halogenated aromatic carboxylic acids are decarboxylated by heating them in the presence of water at temperatures of 80.degree. to 180.degree. C. and in the presence of water and other acids at temperatures above 80.degree. C.
摘要:
Alkyl-(3-chlorophenyl)-sulphones are particularly advantageously obtained by chlorination of alkylphenylsulphones if alkylphenylsulphones are chlorinated in molten form with elemental chlorine in the presence of iron(III) chloride and optionally iodine and/or sulphur.
摘要:
In a particularly advantageous process for producing 2-cyanoindan-1-ones from 2-halogenated indan-1-ones by reaction with a cyanide salt, the cyanide salt is dissolved in a dipolar aprotic solvent or in a water-miscible ether and 2-halogenated indan-1-one is metered into this solution.
摘要:
Hydroxypivalic acid is obtained from aqueous solutions by removal of the water by azeotropic distillation and subsequent crystallization from a solvent mixture which is composed of a polar and a non-polar component. The distillation is carried out under reduced pressure and at a maximum bottom temperature of 90.degree. C., until a residual water content of at least 0.1% of the total weight of the resulting solution is achieved.
摘要:
A process for separating off poorly soluble by-products from reaction mixtures which are produced in the oxidation of p-cresol with oxygen or an oxygen-containing gas in methanol as solvent in the presence of alkali metal hydroxide and in the presence of metal compounds as catalyst, is characterized in that, after the oxidation, excess alkali is neutralized to the extent that a salt precipitate forms and this salt precipitate is separated off together with the poorly soluble by-products.
摘要:
Diphenylamine can be dehydrocyclized on noble metal catalysts in the liquid phase at temperatures of 200.degree. to 340.degree. C. The reaction proceeds with a surprisingly high selectivity.