摘要:
4-Oxaaldehydes of the formula ##STR1## are prepared by catalytic isomerization of 1,3-dioxanes by a process in which a 1,3-dioxane of the formula ##STR2## where R.sup.1, R.sup.2, R.sup.4 and R.sup.5 are identical or different and are each hydrogen, a straight-chain or branched alkyl, alkenyl or alkynyl radical of not more than 18 carbon atoms, a cycloalkyl or cycloalkenyl radical of 5 to 8 carbon atoms, an aryl, alkylaryl, aralkyl or alkenylaryl radical of 5 to 16 carbon atoms or a heterocyclic radical, and furthermore R.sup.1 and R.sup.2 and/or R.sup.4 and R.sup.5 together with the carbon atom to which they are bonded may form a cycloalkane, a cycloalkene or a heterocyclic structure, and the stated radicals may furthermore carry substituents which are inert under the reaction conditions, and R.sup.3 is hydrogen or straight-chain or branched alkyl, is isomerized using a phosphate as a catalyst.
摘要:
A process for the preparation of a 2-(3-aminopropyl)-cycloalkylamine of the general formula I ##STR1## in which the subscript n is an integer from 1 to 4, from a 2-(2-cyanoethyl)-cycloalkanone of the general formula II ##STR2## in which the subscript n has the meaning stated, wherein the following stages are carried out in discrete reaction chambers:a) the 2-(2-cyanoethyl)-cycloalkanone of formula II is reacted in a first reaction chamber with excess ammonia over an acidic heterogeneous catalyst at a temperature from 20.degree. to 150.degree. C. and a pressure of from 15 to 500 bar, andb) in a second reaction chamber, the reaction product from stage a) is hydrogenated at a temperature of from 60.degree. to 150.degree. C. and a pressure of from 50 to 300 bar in the presence of excess ammonia over a catalyst containing cobalt, nickel, ruthenium, and/or some other noble metal, which catalyst optionally contains a basic component or is supported on neutral or basic supporting material.
摘要:
Cyclopentenones of the formula I ##STR1## where each of R.sup.1 to R.sup.4 is independently of the others hydrogen or an organic radical, are prepared by converting a carboxylic ester of the formula IIa, IIb or IIcR.sup.1 CH.dbd.CR.sup.2 --CHR.sup.3 --CHR.sup.4 --CO.sub.2 R.sup.5 (IIa) and/orR.sup.1 CH.sub.2 --CR.sup.2 .dbd.CR.sup.3 --CHR.sup.4 --CO.sub.2 R.sup.5(IIb) and/orR.sup.1 CH.sub.2 --CHR.sup.2 --CR.sup.3 .dbd.CR.sup.4 --CO.sub.2 R.sup.5(IIc),where each of R.sup.1 to R.sup.4 is as defined above and R.sup.5 is C.sub.1 -C.sub.8 -alkyl, over an acidic heterogeneous catalyst at 50.degree.-800.degree. C. and 0.001-50 bar.
摘要:
Cyclic 6-membered to 8-membered 1,2-vinylenedioxy compounds of the general formula I ##STR1## where A is ##STR2## R.sup.1 to R.sup.7 independently of one another are each hydrogen, C.sub.1 -C.sub.8 -alkyl, C.sub.2 -C.sub.16 -alkoxyalkyl, C.sub.2 -C.sub.8 -alkenyl, C.sub.2 -C.sub.8 -alkynyl, C.sub.5 -C.sub.8 -cycloalkyl, aryl, C.sub.7 -C.sub.10 -alkylphenyl, C.sub.7 -C.sub.10 -phenalkyl, C.sub.8 -C.sub.10 -phenalkenyl or a heterocyclic structure, or R.sup.2 and R.sup.3, R.sup.2 and R.sup.4, R.sup.3 and R.sup.4, R.sup.2 and R.sup.6, R.sup.3 and R.sup.6, R.sup.4 and R.sup.5 or R.sup.6 and R.sup.7 together form a cycloaliphatic or heterocyclic ring, and R.sup.1 to R.sup.7 may furthermore carry substituents which are inert under the reaction conditions, and n is 0 or 1, are prepared by a process in which a cyclic 2-oxymethyl-1,3-dioxa compound or one of its derivatives of the general formula II ##STR3## where R.sup.1 to R.sup.7, A and n have the abovementioned meanings, and R.sup.8 is hydrogen or C.sub.1 -C.sub.12 -alkyl, is converted in the presence of an acidic catalyst at from 150.degree. to 450.degree. C. and under from 0.001 to 50 bar, some of the compounds obtained being novel.
摘要:
2-Methylalk-2-enals of the formula ##STR1## where R.sup.1 and R.sup.2 are each hydrogen, alkyl or an aromatic radical, are prepared by isomerization of an acrolein derivative of the formula ##STR2## with a zeolite catalyst, an aluminum silicate and/or an aluminum phosphate.
摘要:
4-oxaaldehydes of the formula ##STR1## are prepared by catalytic isomerization of 1,3-dioxanes by a process in which a 1,3-dioxane of the formula ##STR2## where R.sup.1, R.sup.2, R.sup.4 and R.sup.5 are identical or different and are each hydrogen, a straight-chain or branched alkyl, alkenyl or alkynyl radical of not more than 18 carbon atoms, a cycloalkyl or cycloalkenyl radical of 5 to 8 carbon atoms, an aryl, alkylaryl, aralkyl, aralkenyl or alkenylaryl radical of 5 to 16 carbon atoms or a heterocyclic radical and furthermore R.sup.1 and R.sup.2 and/or R.sup.4 and R.sup.5 together with the carbon atoms to which they are bonded may form a cycloalkane, a cycloalkene or a heterocyclic structure, and the stated radicals may furthermore carry substituents which are inert under the reaction conditions, and R.sup.3 is hydrogen or straight-chain or branched alkyl, is isomerized using a metal oxide catalyst, which has been treated with an acid, and/or a silica phase having a zeolite structure.
摘要:
Olefinically unsaturated carboxylic esters having a terminal ester group and of the general formulae Ia and IbR.sup.1 --CH.sub.2 --CH.dbd.CH--(CH.sub.2).sub.r--1 --COOR.sup.2 (Ia)R.sup.1 --CH.dbd.CH--(CH.sub.2).sub.r --COOR.sup.2 (Ib)and, if desired, further double bond isomers, where R.sup.1 is hydrogen or an organic radical, R.sup.2 is C.sub.1 -C.sub.8 -alkyl and r is from 1 to 20, are prepared by a process in which an .alpha.-substituted .alpha.,.omega.-(n-alkylenedicarboxylic ester) of the general formula II ##STR1## where R.sup.1 and R.sup.2 and r have the abovementioned meanings and R.sup.3 is C.sub.1 -C.sub.8 -alkyl, is converted over an acidic heterogeneous catalyst at from 150.degree. to 800.degree. C. and under from 0.01 to 50 bar.
摘要:
Pentenoic esters are prepared by heating formylvaleric esters at from 50.degree. to 400.degree. C. in the presence of zeolites or one or more phosphates selected from the group consisting of aluminum phosphate, silicon aluminum phosphate, boron aluminum phosphate, silicon iron aluminum phosphate, cerium phosphate, zirconium phosphate, boron phosphate, iron phosphate and strontium phosphate.