摘要:
In the preparation of a 1-alkyl- and 2-aryl-thio-methylphenol of the formula ##STR1## in which R.sup.1 is, or the radicals R.sup.1 are, in the 3-, 5- and/or 6-positions relative to the hydroxyl group and each independently is a hydrogen or halogen atom, or an alkyl, cycloalkyl, aryl, aralkyl or alkoxy group,n is 1, 2, or 3, andR.sup.2 is an optionally substituted alkyl group having 1 to 12 carbon atoms, an optionally substituted cycloalkyl group having 3 to 6 carbon atoms, an optionally substituted phenyl radical or an optionally substituted aralkyl radical,by reacting a phenol of the formula ##STR2## with formaldehyde or an formaldehyde producing compound and with a mercaptan or a thiophenol of the formulaR.sup.2 --S--H.the improvement which comprises effecting the reaction at a temperature of about 90.degree. to 220.degree. C. in the presence of at least one compound of lithium, magnesium, calcium, strontium, barium, zinc, cadmium, lead, manganese, cobalt, nickel, cooper, iron, chromium and aluminum as a catalyst. The products are obtained in high yield and selectivity.
摘要:
A process for the preparation of pure 2-hydroxybenzyl alcohol, pure 4-hydroxybenzyl alcohol or a mixture of both hydroxybenzyl alcohols by reacting phenol and formaldehyde in the presence of a basic catalyst and subjecting the resulting reaction mixture to an at least 2-stage countercurrent extraction in a solvent system of water/organic solvent which is water-immiscible or water-miscible only to a limited extent.
摘要:
A process for the continuous preparation of a ditertiary butylcresol wherein m- or p-cresol is reacted with isobutene at elevated temperature using H.sub.2 SO.sub.4 as catalyst wherein the process is carried out stepwise by introducing stepwise into a reaction mixture comprising substantially all of the cresol to be reacted with isobutene. The total amount of isobutene introduced is introduced such that less isobutene is charged in a last stage of the process than in the first stage thereof. Thereafter the catalyst is deactivated.
摘要翻译:连续制备二叔丁基甲酚的方法,其中使用H 2 SO 4作为催化剂,在高温下使异丙烯与异丁烯反应,其中该步骤通过逐步引入含有基本上所有甲酚的反应混合物来逐步进行 与异丁烯反应。 导入的异丁烯的总量被引入,使得在该方法的最后阶段比在第一阶段中加入较少的异丁烯。 此后催化剂失活。
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:
Particularly pure di-C.sub.1 -C.sub.4 -alkyl 5-nitro-isophthalates are obtained in good yield and in a simple process by dissolving 5-nitro-isophthalic acid in a mixture of a C.sub.1 -C.sub.4 -alkyl alcohol and a solvent which is miscible or only partially miscible with water, heating in the presence of a strong acid, thus forming a second, aqueous phase, crystallizing out, after the esterification reaction has ended, the di-C.sub.1 -C.sub.4 -alkyl 5-nitro-isophthalate formed from the organic phase by cooling and removing the aqueous phase before or after the di-C.sub.1 -C.sub.4 -alkyl 5-nitro-isophthalate is separated off.
摘要:
2-Amino-6-chlorophenyl-alkylsulfanes are prepared in a particularly advantageous manner by hydrogenating 2-chloro-6-nitrophenyl-alkylsulfanes catalytically in the presence of a solvent without the addition of a further sulfur compound, and the novel compound 2-amino-6-chlorophenyl-isopropylsulfane is provided.
摘要:
Hydroxypivalic acid can be prepared by oxidation of hydroxypivalaldehyde with hydrogen peroxide by metering the hydrogen peroxide, as the oxidizing agent, into an aqueous hydroxypivalaldehyde reservoir in the temperature range from 60.degree. to 80.degree. C. such that a hydrogen peroxide concentration of 4% by weight, based on the total weight of the reaction mixture, is not exceeded, and ending the addition of hydrogen peroxide as soon as the concentration of hydroxypivalaldehyde in the reaction mixture falls below 1% by weight.
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:
A mixture of 2,4-dichloro-5-fluorotoluene and 2,6-dichloro-3-fluorotoluene which cannot be separated in an economically efficient manner and can be reacted individually to give the corresponding benzonitriles is subjected according to the invention to ammoxidation in the form of this mixture and then separated at the stage of the benzonitriles by methods known to the person skilled in the art.
摘要:
Alkylhydrazine salts are prepared on an industrial scale and with good results by reacting together hydrazine, an alkene and a strong protonic acid in the presence of water, hydrazine and the protonic acid being introduced, the alkene being added, the liquid and gaseous phases present in the reaction vessel being intensively mixed together at 75.degree. to 150.degree. C., then the reaction mixture being cooled to temperatures below 60.degree. C., the precipitated alkylhydrazine salt being separated off, hydrazine and strong protonic acid being again added to the mother liquor, then alkene being added again and the next reaction cycle being thus carried out.