This invention provides a method for preparing 3,3-dimethylbutyraldehyde from 3,3-dimethylbutanol using an oxidizing component. In one embodiment, 3,3-dimethylbutanol is oxidized to 3,3-dimethylbutyraldehyde in the vapor phase by contacting it with an oxidizing metal oxide compound. In another embodiment, the oxidation of 3,3-dimethylbutanol is carried out by treating it with 2,2,6,6-tetramethyl-1-piperidinyloxy, free radical and an oxidizing agent in a solvent to produce 3,3-dimethylbutyraldehyde. The method of this invention provides a commercially practicable means of preparing 3,3-dimethylbutyraldehyde.
The invention relates to a process for the selective oxidation of alcohols to ketones or to aldehydes by means of an alkali hypohalite under alkaline conditions, which comprises carrying out the oxidation in the presence of a heterogeneous oxidation catalyst that is insoluble in the reaction medium and is selected from the group comprising the compounds of formula (I) ##STR1## ##STR2## (III), wherein n is a number from 3 to 3000; or a 4-oxy-2,2,6,6-tetramethylpiperidin-1-oxyl that is 4-oxy-bound to a Merrifield polymer. The invention relates also to the compounds of formulae (II) and (III) and to the use of the above-mentioned oxidation catalysts for the oxidation of alcohols.
The invention relates to a process for the selective oxidation of alcohols to ketones or to aldehydes by means of an alkali hypohalite under alkaline conditions, which comprises carrying out the oxidation in the presence of a heterogeneous oxidation catalyst that is insoluble in the reaction medium and is selected from the group comprising the compounds of formula (I) ##STR1## ##STR2## wherein n is a number from 3 to 3000; or a 4-oxy-2,2,6,6-tetramethylpiperidin-1-oxyl that is 4-oxy-bound to a Merrifield polymer. The invention relates also to the compounds of formulae (II) and (III) and to the use of the above-mentioned oxidation catalysts for the oxidation of alcohols.
The present invention relates to a process of oxidation of alcohols selectively to aldehydes or ketones with molecular oxygen using a TEMPO based catalyst, Fe-bipyridyl or Fe-phenantroline co-catalyst and N-bromosuccinimide promoter in acetic acid solvent. The oxidation takes places at high rates and high aldehyde selectivity at temperatures in the range 45-50.degree. C. and oxygen or air pressures of 0-15 psi. The alcohol conversion of 95-100% and aldehyde selectivity higher than 95% are achieved over 3-4 hours reaction time. Aldehydes such as 3,3-dimethyl-1-butanal can be produced efficiently using the present invention.
The present invention relates to a process of oxidation of alcohols selectively to aldehydes or ketones with NaOCl using a TEMPO--borate catalyst system. It is shown that the oxidation can be efficiently carried out without KBr additives under solvent free conditions. Aldehydes such as 3,3-dimethylbutyraldehyde can be produced efficiently using the present invention.
3,3-Dimethylbutanal is prepared from 3,3-dimethylbutanol. Intermediate 3,3-dimethylbutanol is obtained by reacting ethylene, isopropylene and a mineral acid to produce a 3,3-dimethylbutyl ester which is hydrolyzed to the alcohol. The hydrolysis step is effectively carried out by reactive distillation. Alternatively, 3,3-dimethylbutanal is prepared from 3,3-dimethylbutanol obtained by reduction of the corresponding carboxylic acid or 1,2-epoxy-3,3-dimethylbutane, or by hydrolysis of 1-halo-3,3-dimethylbutane. Fixed bed gas phase and stirred tank liquid phase processes are provided for converting 3,3-dimethylbutanol to 3,3-dimethylbutanal by catalytic dehydrogenation.
