摘要:
Process for the preparation of 1-methylcyclopentene by thermal reaction of cyclohexanol or cyclohexene or mixtures of both compounds to give 1-methylcyclopentene, wherein the resulting by-products 3-methylcyclopentene and 4-methylcyclopentene (double-bond isomers of 1-methylcyclopentene) are returned to the reaction.
摘要:
Process for the preparation of cyclopentane derivatives of the formula I in which R is a C1- to C10-alkyl group, which comprises reacting cyclohexanol or cyclohexene or mixtures of both compounds to give 1-methyl-1-cyclopentene (1st stage) and subsequently adding a C1- to C10-alkanol onto the double bond of the 1-methyl-1-cyclopentene (2nd stage).
摘要:
A process for the preparation of 2-oxo-[1,3] dioxolane-4-carboxylic acid esters of formula I with R being an organic group comprising 1 to 10 carbon atoms, wherein an oxirane-2-carboxylic acid ester of formula II is reacted with carbon dioxide (CO2) at a pressure of at least 35 bars and a temperature of 60 to 80° C.
摘要:
Ketones of the formula II where A is optionally alkyl-substituted C2-C12-alkanediyl, R1 and R2 are each, independently of one another, C1-C6-alkyl, or R1 and R2 together form optionally alkyl-substituted C3-C10-alkanediyl, and R3 is hydrogen or C1-C6-alkyl, are prepared by reacting a cyclic olefin of the formula I with dinitrogen monoxide to form the ketone of the formula II. The ketone of the formula II can be further hydrogenated to form the saturated ketone of the formula III. Macrocyclic ketones of the formula III, e.g. muscone, are sought after as fragrances.
摘要:
A process for the preparation of acyloins of the general formula I ##STR1## in which R.sup.a and R.sup.b are the same or different and stand for hydrogen or an optionally substituted C.sub.1 -C.sub.20 alkyl, an optionally substituted C.sub.6 -C.sub.10 aryl, an optionally substituted C.sub.7 -C.sub.12 aralkyl, an optionally substituted heteroaryl, or an optionally substituted heterocycloalkyl group, except for autocondensation products of formaldehyde, wherein an aldehyde of the formula II R.sup.a CHO, (II) is reacted, in the presence of a catalyst, with an aldehyde of the formula III R.sup.b CHO, (III) in which R.sup.a and R.sup.b have the above meanings and at least one of the radicals R.sup.a and R.sup.b denotes a radical other than hydrogen, which have been produced, with the assistance of an auxiliary base, from a triazolium salt of the formula IV ##STR2##
摘要:
The invention relates to a process for the oxidation of mesitol with singlet oxygen, which is released from hydrogen peroxide, this release taking place in the presence of a bismuth compound as catalyst. In the process, 2,4,6-trimethylquinol is formed in high yield and selectivity as product, which can be used in further reactions for the synthesis of vitamins and in particular of vitamin A and vitamin E.
摘要:
Ketones of the formula II where A is optionally alkyl-substituted C2-C12-alkanediyl, R1 and R2 are each, independently of one another, C1-C6-alkyl, or R1 and R2 together form optionally alkyl-substituted C3-C10-alkanediyl, and R3 is hydrogen or C1-C6-alkyl, are prepared by reacting a cyclic olefin of the formula I with dinitrogen monoxide to form the ketone of the formula II. The ketone of the formula II can be further hydrogenated to form the saturated ketone of the formula III. Macrocyclic ketones of the formula III, e.g. muscone, are sought after as fragrances.
摘要:
A process for the preparation of 1,2,4-triazolium salts Ia ##STR1## where R.sup.1, and R.sup.2 and R.sup.3 are C-organic radicals, it being possible for R.sup.2 and R.sup.3 to be connected to give a 5- to 8-membered ring, R.sup.4 is hydrogen or an organic radical and A is an equivalent of an anion, by reacting an amidrazone II ##STR2## with a carboxylic acid III R.sup.4 --COOH II or a functional derivative (IIIa) of this acid, an anion A being formed from III or IIIa which, optionally, can be replaced by another anion. The triazolium salts have great industrial importance as catalysts for the preparation of acyloine from aldehydes.
摘要:
The invention relates to a process for the oxidation of mesitol with singlet oxygen, which is released from hydrogen peroxide, this release taking place in the presence of a bismuth compound as catalyst. In the process, 2,4,6-trimethylquinol is formed in high yield and selectivity as product, which can be used in further reactions for the synthesis of vitamins and in particular of vitamin A and vitamin E.
摘要:
The present invention relates to a process for carrying out a chemical reaction in the presence of a ruthenium-carbene complex supported on silicon dioxide in a continuously operated reactor and also the use of corresponding supported catalysts in continuously operated reactors.