摘要:
Process to reduce stereoselectively 3alpha-hydroxy-7-keto-5beta-cholanic acid to 3alpha,7beta-dihydroxy-5beta-cholanic acid in ter.alcohols by using, as reducing agent, sodium metal in the presence of other metal salts.Examples of metal salts particularly useful are: potassium, cesium and rhubidium organic salts and, more particularly, potassium acetate or potassium ter.butylate.
摘要:
Process industrially and economically useful for preparing difunctional aliphatic organic compounds of formulaX-(CH.sub.2).sub.n -Yin which n=6,7, X=--COOH, --COOR, Y=--CN, --COOH, --CONH.sub.2, --CH.sub.2 --NH.sub.2 --COOR wherein R is a linear or branched alkyl containing 1-6 carbon atoms.The process starts from a ketone of the formula ##STR1## in which n=2,3 and R.sub.1 =--CN, --COOH. The ketone (I) is changed to the corresponding hydroperoxide by means of H.sub.2 O.sub.2, the hydroperoxide is catalytically split by means of a catalyst Fe.sup.++ /Cu.sup.++ to give an unsaturated acid of the formulaHOOC--(CH.sub.2).sub.3 --CH.dbd.CH--(CH.sub.2).sub.2 -R.sub.1and this is catalytically hydrogenated to the compoundHOOC--(CH.sub.2).sub.n -R.sub.1When R.sub.1 is different from Y, R.sub.1 is changed to Y through known methods.
摘要:
Process for the preparation of hydroperoxides of alkylbenzenes characterized by the fact that the alkylbenzene reacts with oxygen in the presence of a catalytic system which includes an N-hydroxyimide or an N-hydroxysulfamide and a polar solvent.
摘要:
A process for the preparation of 5-(2,4-difluorophenyl)-salicylic acid comprising the reaction of an organometallic derivative with a suitable substituted benzene in the presence of a transition-metal based catalyst is described.
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:
A process for the selective side-chain halogenation of alkylaromatic hydrocarbons, consisting of reacting the hydrocarbon with an N-halogenoamine in the presence of a proton donor and a metal ion.
摘要:
Aliphatic carboxylic acids of formulae (Ib) R1—COOH(Ia) and R2—COOH wherein R1 is tertiary C4-20-alkyl and R2 together are —(CH2)n— with n=3 to 10, are produced by oxidizing an aliphatic or alicyclic ketone of the formula (II): wherein R1 and R2 are as defined above, with molecular oxygen in the presence of a soluble manganese (II) compound. The process has a high selectivity and is carried out under very mild conditions. It is especially useful for the production of dicarboxylic acids, such as, adipic acid, from cyclic ketones.
摘要:
A process for the preparation of 5-(2,4-difluorophenyl)-salicylic acid comprising the reaction of an organometallic derivative with a suitable substituted benzene in the presence of a transition-metal based catalyst is described.
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.
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.