摘要:
The invention provides novel mepiquat plant growth regulator compositions which have improved hygroscopicity and corrosion characteristics. The novel mepiquat plant growth regulator compositions of the invention can be readily prepared from technical mepiquat chlorid inter alia by electrochemical ion exchange processes or by quaternization of N-methylpiperidine with dimethylcarbonate as starting material.
摘要:
The invention provides novel mepiquat plant growth regulator compositions which have improved hygroscopicity and corrosion characteristics. The novel mepiquat plant growth regulator compositions of the invention can be readily prepared from technical mepiquat chlorid inter alia by electrochemical ion exchange processes or by quaternization of N-methylpiperidine with dimethylcarbonate as starting material.
摘要:
The invention provides novel mepiquat plant growth regulator compositions which have improved hygroscopicity and corrosion characteristics. The novel mepiquat plant growth regulator compositions of the invention can be readily prepared from technical mepiquat chlorid inter alia by electrochemical ion exchange processes or by quaternization of N-methylpiperidine with dimethylcarbonate as starting material.
摘要:
Methods of preparing or purifying onium hydroxides of the elements N, S or P by electrodialysis involve an electrodialysis apparatus comprising one or more cell units, each cell unit comprising a bipolar membrane and an anion-selective membrane, and a bipolar membrane or a cation-selective membrane being located on the anode side between the last anion-selective membrane and the anode.
摘要:
The invention relates to a process for the preparation of m-substituted phenylalkanols of the formula (I) in which R1 is C1-C5-alkyl and R2, R3, R4 and R5, independently of one another, are hydrogen or methyl, wherein a p-substituted phenylalkanol of the formula (II) in which R1, R2, R3, R4 and R5 having the meanings given under formula (I), is isomerized in the presence of a Friedel-Crafts catalyst to give an m-substituted phenylalkanol of the formula (I). From the m-substituted phenylalkanols of the formula (I) it is possible to form, by oxidation or dehydrogenation, as products of value, the corresponding aldehydes, which are known as fragrances and aroma chemicals.
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 invention relates to a process for the preparation of m-substituted alkyltoluenes of the formula (I) in which R1 is C1-C5-alkyl, wherein a p-substituted alkyltoluene of the formula (II) in which R1 has the meaning given under formula (I), is isomerized in the presence of ionic liquids to give an m-substituted alkyltoluene of the formula (I). The m-substituted alkyltoluenes obtainable according to the invention are starting compounds for the preparation of fragrances and aroma substances.
摘要:
The process for the preparation of carbonyl compounds of the formula I where R1 and R2 are a hydrocarbon radical, or R1 and R2 together are an unsubstituted or substituted alkylene group, and X is=O or two alkoxy groups, comprises oxidizing alcohols of the formula II where R1 to R2 and X are as defined above, with oxygen in the gaseous phase a) at temperatures of from 270 to 600° C. on silver coated catalysts which comprise an abrasion-resistant coating of metallic silver on a core of inert support material, or b) at temperatures of from 450 to 750° C. on silver crystals and/or copper crystals having a particle size of from 0.1 to 2.5 mm for a residence time of at most 0.1 second. Also claimed is an advantageous overall process for the preparation of &agr;-diketones, preferably diacetal, from the corresponding ketone, in particular methyl ethyl ketone, via the carbonyl compounds of the formula I where X is two alkoxy groups.
摘要:
The present invention relates to a process for preparing 2-methyl-3-(4-tert-butyl-phenyl)propanal with high para-isomer purity, and also to a process for preparing 4-tert-butylbenzaldehyde with high para-isomer purity.
摘要:
The invention relates to a process for the preparation of m-substituted alkyltoluenes of the formula (I) in which R1 is C1-C5-alkyl, wherein a p-substituted alkyltoluene of the formula (II) in which R1 has the meaning given under formula (I), is isomerized in the presence of ionic liquids to give an m-substituted alkyltoluene of the formula (I). The m-substituted alkyltoluenes obtainable according to the invention are starting compounds for the preparation of fragrances and aroma substances.