摘要:
Process for preparing 1,1,4,4-tetraalkoxybut-2-ene derivatives of the general formula (I), where the radicals R1 and R2 are each, independently of one another, hydrogen, C1-C6-alkyl, C6-C12-aryl, such as phenyl, or C5-C12-cycloalkyl or R1 and R2 together with the double bond to which they are bound form a C6-C12-aryl radical, such as phenyl, a phenyl radical substituted by one or more C1-C6-alkyl groups, halogen atoms or alkoxy groups or a monounsaturated or polyunsaturated C5-C12-cycloalkyl radical, R3, R4 are each, independently of one another, hydrogen, methyl, trifluoromethyl or nitrile, which comprises electrochemically oxidizing 1,4-dialkoxy-1,3-butadiene of the formula II where the radicals R1, R3 and R4 have the same meanings as in the formula I, in the presence of a C1-C6-alkyl alcohol.
摘要:
A process for the preparation of 2,5-dihydrofuran derivatives substituted in the 3- or 4-position, which in the 2- or in the 5-position or at both positions each carry a C1- to C6-alkoxy radical (DHF-alkoxy derivatives 1), or 1,1,4,4-tetraalkoxy-but-2-ene derivatives substituted in the 3- or 4-position, from 2-butene-1 ,4-diol derivatives of the general formula (I) in which the radicals R1 and R2 independently of one another are hydrogen, C1- to C6-alkyl, C6- to C12-aryl or C5- to C12-cycloalkylene orR1 and R2, together with the double bond to which they are bonded, form a C6- to C12-aryl radical or a mono- or polyunsaturated C5- to C12-cycloalkyl radical,orfrom their mixture with 2,5-dihydrofuran derivatives substituted in the 3- position or 4-position, which in the 2- or in the 5-position carry a C1- to C6-alkoxy radical, by electro-chemical oxidation in the presence of a C1- to C6-monoalkyl alcohol.
摘要:
Process for preparing primary amines having a cyclopropyl unit and a primary amino group bound to an aliphatic or cycloaliphatic carbon atom (amine A) by cathodically reducing oximes having a cyclopropyl unit or oxime derivatives in which the hydrogen atom in the oxime group has been replaced by an alkyl or acyl group (oxime O) at a temperature of from 50 to 100° C. in an essentially anhydrous electrolyte solution in a divided electrolysis cell.
摘要:
Process for preparing primary amines having a cyclopropyl unit and a primary amino group bound to an aliphatic or cycloaliphatic carbon atom (amine A) by cathodically reducing oximes having a cyclopropyl unit or oxime derivatives in which the hydrogen atom in the oxime group has been replaced by an alkyl or acyl group (oxime O) at a temperature of from 50 to 100° C. in an essentially anhydrous electrolyte solution in a divided electrolysis cell.
摘要:
Process for preparing 2-alkyne 1-acetals of the general formula I, where the radicals have the following meanings: R1 is hydrogen, C1-C20-alkyl, C2-C20-alkenyl, C2-C20-alkynyl, C3-C12-cycloalkyl, C4-C20-cycloalkylalkyl, C4-C10-aryl, with these radicals optionally being able to be substituted by hydroxy, halogen, C1-C6-alkoxy, (C1-C6-alkoxy)carbonyl, carboxyl or nitrile groups, R2 is C1-C6-alkyl or a radical of the general formula II where R1 is as defined above, R3 has the same meaning as the radical R2, by electrochemically oxidizing a compound of the general formula III where the radical R1 has the same meaning as in the general formula I, in the presence of C1-C6-alkyl alcohols (alcohol A) or as such.
摘要:
The invention relates to a process for the preparation of m- or p-substituted phenylalkanols of the formula (I) in which R1 is bonded to the phenyl ring in the m- or p-position and is C1-C5-alkyl, and R2, R3, R4 and R5, independently of one another, are hydrogen or methyl, wherein an unsubstituted phenylalkanol of the formula (II) in which R2, R3, R4 and R5 have the meanings given under formula (I) is alkylated together with a C1-C5-alkyl halide of the formula (III) R1-Hal (III), in which R1 has the meaning given under formula (I) and Hal is halogen, in the presence of a Friedel-Crafts catalyst to give an m- or p-alkyl-substituted phenylalkanol of the formula (I), then the reaction mixture is worked-up and the desired m- or p-alkyl-substituted phenylalkanol of the formula (I) is separated off, the other formed by-products are returned to the reaction mixture and these are isomerized in the presence of a Friedel-Crafts catalyst to give the desired m- or p-alkyl-substituted phenylalkanol. From the m- or p-alkyl-substituted phenylalkanols of the formula (I), it is possible to form, by oxidation or dehydrogenation, as products of value, the corresponding aldehydes, which play an interesting role as fragrances and aroma chemicals.
摘要:
The present invention relates to 3-tert-butylbenzaldehyde dimethyl acetal and to 3-tert-butylbenzyl methyl ether and to an electrochemical method for producing 3-tert-butyl-benzaldehyde dimethyl acetal and intermediates passed through in said method.
摘要:
The present invention relates to a process for the preparation of 2-substituted 4-hydroxy-4-methyltetrahydropyranols by reacting 3-methylbut-3-en-1-ol (isoprenol) with the corresponding aldehydes in the presence of a strongly acidic cation exchanger. Specifically, the present invention relates to a corresponding process for the preparation of 2-isobutyl-4-hydroxy-4-methyltetrahydropyran by reacting isoprenol with isovaleraldehyde.
摘要:
The present invention relates to 3-tert-butylbenzaldehyde dimethyl acetal and to 3-tert-butylbenzyl methyl ether and to an electrochemical method for producing 3-tert-butyl-benzaldehyde dimethyl acetal and intermediates passed through in said method.
摘要:
The present invention relates to a process for preparing an amine, which comprises the step cathodic reduction of a corresponding oxime derivative of the general formula (I) where R is C1-6-alkyl or C2-6-alkenyl which is optionally substituted by one or more substituents selected independently from the group consisting of phenyl, O—C1-6-alkyl, NH—C1-6-alkyl, N(C1-6-alkyl)2, OH and NH2; R1 is H; C1-6-alkyl or C(O)—C1-6-alkyl and A is a 5-, 6- or 7-membered hydrocarbon ring which is saturated or has a double bond and in which at least one CH2 group may, if appropriate, be replaced by —O—, —S— —NH—, —N═ or —N(C1-6-alkyl)- and which may optionally be substituted by one or more further substituents selected independently from the group consisting of phenyl, C1-6-alkyl, O—C1-6-alkyl, NH—C1-6-alkyl, N(C1-6-alkyl)2, OH and NH2; wherein, based on the ring carbon bearing the substituent R, the oxime derivative has an excess of the R or S form of at least 10%.