Patent GB-640537-A (GB)
Title: Improvements in preparation of ketones
IPC: C07C45/00
Filed: 1947-12-19
Abstract: Liquid ketones of formula R.CO.(X)n.H where n is 1-4, R is n- or sec.-alkyl, cycloalkyl or aralkyl, and X is the residue of a 1-alkene containing at least 3 carbon atoms, are prepared by heating the 1-alkene with the appropriate aldehyde RCHO in relative proportions of from 1-20 mols. of aldehyde to 1 mol. of 1-alkene in presence of a peroxidic catalyst which will decompose to give free radicals at the reaction temperature of 65-100 DEG  C. High pressures and inert diluents may be used and the catalyst is usually an alkyl or acyl peroxide or hydrogen peroxide.  Specified aldehydes RCHO are octaldehyde, cyclohexylformaldehyde and phenylacetaldehyde.  In the examples, the use of the olefins propene, isobutene, octene-1, decene-1 and dodecene-1 is exemplified in conjunction with the aldehydes acetaldehyde, n- and iso-butyraldehyde and n-heptaldehyde. In most cases mixtures of ketones with some high-boiling fractions are obtained. Specification 583,181 is referred to.  The Specification as open to inspection under Sect. 91 states that monoalkenes containing at least 3 carbon atoms, e.g. butene-2, cycloalkenes, e.g. cyclohexene, and unconjugated dienes, e.g. 1 : 5-hexadiene and 4-vinylcyclohexene, may be used in place of the 1-alkenes.  Any catalyst decomposing to give free radicals may be used and the reaction is not limited as to reaction temperature and reactant ratios.  This subject-matter does not appear in the Specification as accepted.ALSO:Ketones of the formula R.CO.(X)n.H, where R is n- or sec.-alkyl, cycloalkyl or aralkyl, X is the radical derived from the 1-alkene defined below, and n is 1-4, are prepared by treatment of a n- or sec.-alkanal, cycloalkanecarboxaldehyde, or aralkanal with a 1-alkene containing at least three carbon atoms, in the presence of a peroxidic catalyst which will decompose to give free radicals at the reaction temperature of 65-100 DEG  C.  The relative proportion of aldehyde to the 1-alkene is 1-20 mols. to 1 mol.  Specified aldehydes are propionaldehyde, octaldehyde, cyclohexylformaldehyde and phenylacetaldehyde.  Suitable catalysts are the acyl and alkyl peroxides and hydrogen peroxide; an inert diluent may be employed.  The use of high pressures (up to 2000 lb. p.s.i.) is preferred when the olefins are gaseous.  In the examples: (1) propylene is treated with acetaldehyde in the presence of dibenzoyl peroxide at 70 DEG  C. to give methyl propyl and methyl hexyl ketones; (2) isobutylene is similarly treated with n-butyraldehyde to give propyl isobutyl ketone; (3) to (9) the use of the olefins octene-1, decene-1, and dodecene-1, and of the aldehydes, isobutyraldehyde, n-heptaldehyde is exemplified. Specification 583,181 is referred to.  The Specification as open to inspection under Sect. 91 states that any monoalkene containing at least 3 carbon atoms, a cycloalkene, or a diolefin with isolated double bonds may be used in the reaction and examples mentioned are butene-2, cyclopentene, cyclohexene, 1 : 5-hexadiene, and 4-vinylcyclohexene. It is stated that any catalyst which decomposes to give free radicals, e.g. perborates or tetraethyl lead, may be used, and in addition the reaction is not limited as regards temperature and ratio of reactants.  This subject-matter does not appear in the Specification as accepted.