Advances in amination
View Patent ↗Inclusion of a branched alcohol in the catalytic hydrogenation reaction involving an aliphatic nitro compound dramatically increases the efficiency of the conversion of nitro groups into amino groups. This discovery is of particular value in the production of polyalkyleneamines via nitration of a polyalkene, such as a polybutene, and its subsequent reduction. The polyalkyleneamines so produced are useful as dispersant additives for motor oils and fuels.
1. In a two step process for producing an amine compound involving a first nitration step wherein a polyalkene is nitrated in the presence of a hydrocarbon solvent, and a second catalytic hydrogenation step in which the nitrated polyalkene from the first step, its accompanying solvent, and a catalyst are charged to a hydrogenation apparatus for purposes of reduction, wherein the improvement comprises conducting the hydrogenation step in the presence of an effective reduction-enhancing amount of a branched alcohol.
2. A process according to claim 1 wherein said polyalkene is a polybutene having a molecular weight between 300 and 3000, including every integral molecular weight therebetween.
3. A process according to claim 1 wherein said catalyst is selected from the group consisting of: nickel, palladium, and platinum, and their compounds and complexes.
4. A process according to claim 1 wherein said branched alcohol is a primary alcohol having between 8 an 24 carbon atoms per molecule.
5. A process according to claim 1 wherein said branched alcohol has a longest chain of carbon atoms which comprises at least 6 carbon atoms, and wherein the alkyl chain branching includes at least two carbon atoms per branch, and wherein said alkyl chain branching occurs on any carbon atom other than the □-carbon to which the alcoholic —OH group is attached.
6. A process according to claim 5 in which said alcohol is selected from the group consisting of 2-ethyl hexanol; 3,3,5-trimethylhexanol; 2-butyl-1-octanol; and tridecyl alcohol.