摘要:
Process for the continuous preparation of &agr;- and/or &bgr;-ionone or homologous compounds using concentrated sulfuric acid at temperatures from 20 to 90° C., in the presence of organic solvents or diluents with cooling and by subsequent termination of the reaction by hydrolysis of the reaction mixture with water or dilute sulfuric acid, wherein both the cyclization of pseudoionones and the subsequent hydrolysis of the reaction mixture are carried out in a virtually adiabatic reaction in one or more reaction mixing pump(s) which are connected in series and each of which consists essentially of a rotationally symmetrical mixing chamber formed from a peripheral wall and two end walls and of a mixing rotor made of material inert to sulfuric acid and with rotational drive, where the mixing chamber has at least one inlet opening for each component and one outlet opening for the reaction mixture, and annular channels in fluid connection to one another in the end walls, and wherein the heat of the two reactions is in each case partly or wholly removed with the aid of a downstream heat exchanger.
摘要:
The present invention relates to an improved process for preparing higher unsaturated ketones by reacting the corresponding &agr;,&bgr;-unsaturated alcohols with alkyl acetoacetates in a Carroll reaction , in a reactor system with fitted fractionation column, wherein A the &agr;,&bgr;-unsaturated alcohol is introduced into the reaction vessel together with the organic aluminum compound in the absence of effective amounts of a solvent, and the alkyl acetoacetate is metered into this mixture, B a reaction temperature which is as constant as possible at between 175° C. and 220° C., preferably between 180° C. and 200° C., is adjusted and C during the reaction the content of alkyl acetoacetate in the reaction mixture is adjusted to a value which is as constant as possible at between 1 and 3% by weight. It is advantageous in this process for the reaction temperature defined under B to be controlled by suitable variation of the heat input and/or by variation of the rate of addition of the alkyl acetoacetate, and for adequate mixing of the reaction mixture in the reaction vessel to be ensured This can be achieved with the aid of a stirrer, by pumping the reaction mixture through an external liquid circulation, by introducing the alkyl acetoacetate by means of a mixing nozzle or else by passing in a stream of inert gas. The process according to the invention is particularly suitable for the Carroll reaction of higher alcohols such as 3,7-dimethyl-1,6-octadien-3-ol (linalool), 3,7-dimethyl-1-octen-3-ol, 3,7,11-trimethyl-1,6,10-dodecatrien-3-ol (nerolidol), 3,7,11-trimethyl-1-dodecen-3-ol or 3,7,11-trimethyl-1,6-dodecadien-3-ol (dihydronerolidol).
摘要:
Process for the continuous preparation of .alpha.- and/or .beta.-ionone or homologous compounds using concentrated sulfuric acid at temperatures from 20 to 90.degree. C., in the presence of organic solvents or diluents with cooling and by subsequent termination of the reaction by hydrolysis of the reaction mixture with water or dilute sulfuric acid, wherein both the cyclization of pseudoionones and the subsequent hydrolysis of the reaction mixture are carried out in a virtually adiabatic reaction in one or more reaction mixing pump(s) which are connected in series and each of which consists essentially of a rotationally symmetrical mixing chamber formed from a peripheral wall and two end walls and of a mixing rotor made of material inert to sulfuric acid and with rotational drive, where the mixing chamber has at least one inlet opening for each component and one outlet opening for the reaction mixture, and annular channels in fluid connection to one another in the end walls, and wherein the heat of the two reactions is in each case partly or wholly removed with the aid of a downstream heat exchanger.
摘要:
Process for the continuous preparation of unsaturated ketones of the formula I where the dashed line can be an additional C—C bond, R1 is an alkyl, and R2 is an aliphatic hydrocarbon having from 1 to 37 carbons, a cycloalkyl or a cycloalkylalkyl, by reacting an unsaturated alcohol of the formula II with an alkyl acetoacetate of the formula III where R3 is an alkyl having from 1 to 5 carbons, in the presence or organic aluminum compounds as catalyst.
摘要:
A process for preparing .gamma.,.delta.-unsaturated ketones of the general formula I ##STR1## by reacting an allyl alcohol of the general formula II ##STR2## in which R.sup.1 is H or a hydrocarbon radical having 1 to 20 carbon atoms, with diketene or an alkyl acetoacetate of the general formula III ##STR3## in which R.sup.2 is alkyl having 1 to 4 carbon atoms in an unmodified or modified Carroll reaction in the presence of an aluminum catalyst, wherein aluminum compounds which are stable liquids at room temperature, or a mixture of such aluminum compounds, which comprise at least one radical formed from an alkyl acetoacetate and 1 or 2 alkoxy radicals, or else comprise exclusively radicals formed from alkyl acetoacetates, which are esterified with sec-butanol or isobutanol, or else are esterified with at least two different alcohols, are used as aluminum catalyst. Also claimed are the novel mixtures of aluminum compounds which comprise radicals which are formed exclusively from alkyl acetoacetates and are esterified with at least two different alkanols, and the batchwise and continuous preparation of the liquid aluminum catalysts.
摘要:
A process for preparing .gamma.,.delta.-unsaturated ketones bya) reacting vinylcarbinols or propargyl alcohols with alkyl acetoacetates or diketene andb) thermally rearranging the resulting acetoacetates in the presence or absence of an aluminum catalyst to .gamma.,.delta.-unsaturated ketones (Carroll reaction),wherein step a) and/or step b) is carried out in a cyclic carbonate of the formula I or a .gamma.-lactone of the formula II ##STR1## where R.sup.1, R.sup.2 and R.sup.3 are H, or lower alkyl and R.sup.4 is H, lower alkyl, phenyl or methoxymethyl, as solvent.
摘要:
An improved process for preparing lower unsaturated ketones by reacting the corresponding &agr;,&bgr;-unsaturated alcohols with alkyl acetoacetates in a Carroll reaction in the presence of from 0.1 to 5 mol %, based on the alkyl acetoacetate to be reacted, of an organic aluminum compound as catalyst with elimination and continuous removal by distillation of the alkanol eliminated during the reaction from the alkyl acetoacetate in a reactor system with a fitted fractionation column, wherein A an &agr;,&bgr;-unsaturated alcohol which boils below 140° C. is introduced, in the absence of effective amounts of a solvent, together with the organic aluminum compound into the reaction vessel, B a reaction temperature which is as constant as possible between 170° C. and 250° C. is set under elevated pressure, C at this temperature, the alkyl acetoacetate is metered into the mixture, obtained in A, of the &agr;,&bgr;-unsaturated alcohol and the organic aluminum compound, and D during the reaction the content of alkyl acetoacetate in the reaction mixture is set at a value which is as constant as possible between 0.1 and 10% by weight.
摘要:
A process is described for producing adsorbates suitable for human or animal nutrition and also cosmetics applications in which a component (A) to be adsorbed is applied to a carrier (C) using at least one stabilizer (B), the mean particle size of the carrier (C) being at least 80 μm, with the proviso that, if the component (A) to be adsorbed is vitamin E, the mixture of (A) and (B) has an HLB value less than 7, and also with the proviso that if the component (A) to be adsorbed is an oil-soluble vitamin and the stabilizer (B) is a glyceride, the freezing point of the mixture of (A) and (B) is below or equal to 80° C. A description is also given of the use of the adsorbates which are thus obtainable.
摘要:
A process is described for producing adsorbates suitable for human or animal nutrition and also cosmetics applications in which a component (A) to be adsorbed is applied to a carrier (C) using at least one stabilizer (B), the mean particle size of the carrier (C) being at least 80 μm, with the proviso that, if the component (A) to be adsorbed is vitamin E, the mixture of (A) and (B) has an HLB value less than 7, and also with the proviso that if the component (A) to be adsorbed is an oil-soluble vitamin and the stabilizer (B) is a glyceride, the freezing point of the mixture of (A) and (B) is below or equal to 80° C. A description is also given of the use of the adsorbates which are thus obtainable.