摘要:
2-(Arylimino-methyl)-3-dialkylaminoacrylonitriles can be obtained by reaction of .beta.-anilino-acrylonitriles with ortho-formamides. They are suitable as starting substances for the preparation of 4-amino-5-iminiummethylene-2-pyrimidines or 4-amino-5-formyl-2-pyrimidines.
摘要:
N-Phenyl-1-naphthylamine can be prepared by reaction of aniline and 1-naphthylamine in the liquid phase at 100-400.degree. C. under normal pressure, a catalyst mixture comprising boron and fluorine being employed. Such catalyst mixtures can be obtained, for example, by reaction of hydrogen fluoride, boric acid and aniline and/or 1-naphthylamine. The catalyst is recovered and can be employed again. The reaction can be carried out discontinuously or continuously.
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:
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:
4-Hydroxybiphenyl is obtained in non-thixotropic form if a reaction mixture which is obtained by alkaline hydrolysis of biphenyl-4-sulfonic acid and contains 4-hydroxybiphenyl is heated at elevated pressure at above 115.degree. C. and at a pH from 0 to below 6.5.
摘要:
5-Hydroxymethylthiazole is prepared in an improved manner by reducing 5-formylthiazole using a borane compound. Particularly advantageous in this case is the use of 5-formylthiazole which has been obtained by reaction of a 2-halomalonaldehyde compound with thioformamide in the presence of less than 5% by weight of water (based on the reaction mixture).
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:
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:
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.