Patent GB-694353-A (GB)
Title: Manufacture of organic oxygenated compounds
Inventor: HADLEY DAVID JAMES
IPC: C07C45/62
Filed: 1949-03-25
Abstract: The invention comprises alpha-neopentyl- and alpha - methyl - beta - tert. - butyl - acroleins.  They are made by reacting diisobutene in the vapour phase at elevated temperatures with molecular oxygen in the presence of elementary selenium and one or more of the following substances: copper, copper oxides and copper aluminate, chromate, chromite, chloride, molybdate, sulphate, tungstate and vanadate. Small amounts of methacrolein are also produced.  Diisobutene is defined as 2 : 4 : 4-trimethylpent-1- or -2-ene or mixtures thereof, e.g. commercial diisobutene.  Temperatures specified are 200-400 DEG C., preferably 250-350 DEG  C.  The mixed aldehydes may be separated by fractional distillation after isolation from the reaction mixture, e.g. by scrubbing with a solvent, with activated carbon or by condensation.  Oxygen-containing gases such as air may be used and inert gases may be present.  The reactants should be maintained outside the explosion limits either by restricting the available oxygen or by using a diisobutene concentration sufficiently low or so high that even after a part thereof has been oxidized its content remains above the upper explosion limit.  Elementary selenium is preferably added as such with the reactants although it may be obtained in situ from a selenide such as silver, antimony or cobalt selenide.  The 2 : 4-dinitrophenylhydrazones of the products are described.  The products may be separately or in admixture hydrogenated, e.g. in the presence of Raney nickel, the same alcohol, 2 : 4 : 4-trimethylpentan-1-ol resulting.  If partial hydrogenation is effected so that only the double bond becomes saturated, e.g. by using a restricted quantity of hydrogen, 2 : 4 : 4 - trimethylpentanal is obtained from either product.  The latter compound may be oxidized, e.g. with silver oxide, or preferably, with molecular oxygen, to 2 : 4 : 4-trimethyl-pentanoic acid.  In examples: (1) 2 : 4 : 4 - trimethyl - pent - 1 - ene is reacted with air in the presence of selenium and copper aluminate to yield alpha-neopentyl acrolein which on hydrogenation with Adams catalyst after oxidation with p  silver oxide gave 2 : 4 : 4-trimethyl pentanoic acid; (2) the aldehydic fraction isolated from oxidation products of diisobutene is treated with Raney nickel to remove selenium and then hydrogenated in the presence of this catalyst to yield 2 : 4 : 4-trimethyl - pentan - 1 - ol; alpha-neopentyl acrolein is hydrogenated in the presence of Raney nickel to 2 : 4 : 4-trimethylpentanol; and (4) commercial diisobutene is air oxidized in the presence of selenium and copper aluminate to yield the two above acroleins.  Specification 694,362 is referred to.ALSO:Di-isobutene is reacted in the vapour plane at elevated temperatures with molecular oxygen in the presence of elementary selenium and one or more of the following substances:-copper, copper oxides and copper aluminate, chromate, chromite, chloride, molybdate, sulphate, tungstate and vanadate, to produce alphaneopentyl - and alpha - methyl - beta - tert-butyl-acroleins.  Elementary selenium is preferably added as such although it may be obtained in situ from a selenide such as silver, antimony or cobalt selenide.  In Examples (1) a copper aluminate catalyst is made by impregnating activated alumina with a solution of copper nitrate drying and heating in a stream of air until nitrogen oxides ceased to be evolved and this catalyst is used together with elementary selenium added as such in the air oxidation of 2:4:4-trimethyl-1-pentene and in (4) for a similar oxidation of commercial diisobutene.  Reaction details are given in Group IV(b).  Specification 694,362 is referred to.