2,4-dimethyl-5-oxohexane and a method of use therefor
AssigneeStamicarbon B.V.
InventorsAnna M. C. F. Castelijns, Henricus J. Arts, Richard Green
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Abstract
The invention relates to a process for the preparation of high yields of 5-oxohexane nitriles with minimum formation of 1 undesired isomer. Such nitriles may be utilized as starting materials for the preparation of pharmaceutical and agrochemical intermediates and as well as final products. The process comprises reacting a methyl ketone and an .alpha.,.beta.-unsaturated nitrile in the presence of a catalytically effective amount of a strong base. One of the products which may be created by the process is 2,4-dimethyl-5-oxohexane nitrile.
Claims14
A process for the preparation of a 2-methyl-3,5-dialkylpyridine represented by the formula:
- ##STR6## wherein R.sub.1 and R.sub.5 are independently of one another a C.sub.1 to C.sub.20 alkyl group comprising:
- allowing a methyl ketone represented by the formula:
- ##STR7## wherein R.sub.1 is as defined above, and an .alpha.,.beta.-unsaturated nitrile represented by the formula:
- ##STR8## wherein R.sub.3 is H and R.sub.5 is as defined above, to react in the presence of a catalytically effective amount of a strong base which is sufficient to promote the formation a 2,4-dialkyl-5-oxohexane nitrile represented by the formula:
- ##STR9## wherein R.sub.1 and R.sub.5 are as defined above, in high yield and in the substantial absence of undesired isomers;
- and catalytically cyclizing and dehydrogenating the 2,4-dialkyl-5-oxohexane nitrile whereby the 2-methyl-3,5-dialkyl pyridine is obtained.
A process for the preparation of a 2-methylpyridine compound represented by the formula (A):
- ##STR10## wherein R.sub.1 is a C.sub.1 to C.sub.20 alkyl group, R.sub.3 and R.sub.5 are both independently H or a C.sub.1 to C.sub.20 alkyl group but R.sub.3 and R.sub.5 are not both H, comprising
- allowing a methylketone represented by the formula ##STR11## wherein R.sub.1 is as defined above, to react with an .alpha.,.beta.-unsaturated nitrile represented by the formula:
- ##STR12## wherein R.sub.3 and R.sub.5 are as defined above in the presence of a catalytically effective amount of a strong base which is sufficient to promote the formation of a 5-oxohexane nitrile represented by the formula ##STR13## wherein R.sub.1, R.sub.3 and R.sub.5 are as defined above, in high yields and in the substantial absence of undesired isomers, and
- catalytically cyclizing and dehydrogenating the 5-oxohexane nitrile whereby a 2-methylpyridine compound represented by formula (A) is obtained.
Dependencies are inferred from the claim text.