Direct alkylation of N-alkyl-N′-phenyl-p-phenylenediamine

1. A single-step process for the ring alkylation of at least one N-alkyl-N′-phenyl-phenylenediamine with at least one olefin selected from the group consisting of hydrocarbon acyclic monoolefins comprising from 2 to about 50 carbon atoms, cyclic olefins comprising from 5 to 10 carbon atoms, and aryl-substituted monoolefins comprising from 8 to 20 carbon atoms;

wherein said process comprises the single step of heating a mixture of the N-alkyl-N′-phenyl-phenylenediamine(s) and olefin(s) in the presence of a catalytic amount of at least one alkyl aluminum halide at a temperature of from about 50 to about 350° C. in a sealed vessel for from about one to about 30 hours.

2. The process of claim 1 wherein the the N-alkyl-N′-phenyl-phenylenediamine is of the structure:

wherein R 1 is selected from the group consisting of alkyl, cycloalkyl, and radicals of the structural formula:

wherein R 2 may be the same or different and is independently selected from the group consisting of hydrogen and methyl, R 3 is selected from the group consisting of alkyl of from 1 to 12 carbon atoms and n is an integer of from 0 to 6.

3. The process of claim 2 wherein R 1 is selected from the group consisting of alkyls of from 1 to 50 carbon atoms and cycloalkyls of from 3 to 30 carbon atoms.

4. The process of claim 1 wherein the N-alkyl-N′-phenyl-phenylenediamine is selected from the group consisting of:

N-methyl-N′-phenyl-p-phenylenediamine,

N-ethyl-N′-phenyl-p-phenylenediamine,

N-propyl-N′-phenyl-p-phenylenediamine,

N-isopropyl-N′-phenyl-p-phenylenediamine,

N-n-butyl-N′-phenyl-p-phenylenediamine,

N-sec-butyl-N′-phenyl-p-phenylenediamine,

N-n-pentyl-N′-phenyl-p-phenylenediamine,

N-1-methylbutyl-N′-phenyl-p-phenylenediamine,

N-(1-methylheptyl)-N′-phenyl-p-phenylenediamine,

N-1,2-dimethylpropyl-N′-phenyl-p-phenylenediamine,

N-2-methylbutyl-N′-phenyl-p-phenylenediamine,

N-3-methylbutyl-N′-phenyl-p-phenylenediamine,

N-1-ethylpropyl-N′-phenyl-p-phenylenediamine,

N-n-hexyl-N′-phenyl-p-phenylenediamine,

N-1-methylpentyl-N′-phenyl-p-phenylenediamine,

N-2-methylpentyl-N′-phenyl-p-phenylenediamine,

N-3-methylpentyl-N′-phenyl-p-phenylenediamine,

N-4-methylpentyl-N′-phenyl-p-phenylenediamine,

N-1,2-dimethylbutyl-N′-phenyl-p-phenylenediamine,

N-1,3-dimethylbutyl-N′-phenyl-p-phenylenediamine,

N-1-ethylbutyl-N′-phenyl-p-phenylenediamine,

N-2-ethylbutyl-N′-phenyl-p-phenylenediamine,

N-heptyl-N′-phenyl-p-phenylenediamine,

N-octyl-N′-phenyl-p-phenylenediamine,

N-nonyl-N′-phenyl-p-phenylenediamine,

N-decyl-N′-phenyl-p-phenylenediamine,

N-cyclooctyl-N′-phenyl-p-phenylenediamine,

N-cyclohexyl-N′-phenyl-p-phenylenediamine,

N-methylcyclohexyl-N′-phenyl-p-phenylenediamine, and

N-cyclooctyl-N′-phenyl-p-phenylenediamine.

5. The process of claim 1 wherein the N-alkyl-N′-phenyl-phenylenediamine is selected from the group consisting of:

N-(1,3-dimethylbutyl)-N′-phenyl-p-phenylenediamine,

N-isopropyl-N′-phenyl-p-phenylenediamine,

N-(1-methylheptyl)-N′-phenyl-p-phenylenediamine, and

N-cyclohexyl-N′-phenyl-p-phenylenediamine.

6. The process of claim 1 wherein the N-alkyl-N′-phenyl-phenylenediamine is selected from the group consisting of N-(1,3-dimethylbutyl)-N′-phenyl-p-phenylenediamine and N-1isopropyl-N′-phenyl-p-phenylenediamine.

7. The process of claim 1 wherein from about 0.5 mole equivalent to 8 mole equivalents of olefin are added for each mole of N-alkyl-N′-phenyl-phenylenediamine.

8. The process of claim 1 wherein the alkyl aluminum halide is selected from the group consisting of dimethyl aluminum bromide, diethyl aluminum bromide, diethyl aluminum chloride, di-n-propyl aluminum chloride, diisobutyl aluminum iodide, diisobutyl aluminum chloride, diisoamyl aluminum chloride, di-n-dodecyl aluminum chloride, dieicosyl aluminum bromide, methyl aluminum dichloride, ethyl aluminum dichloride, ethyl aluminum dibromide, n-propyl aluminum dichloride, isobutyl aluminum dibromide, n-hexyl aluminum dibromide, sec-decyl aluminum di-iodide, n-dodecyl aluminum dichloride, n-eicosyl aluminum dibromide, methyl aluminum sesquichloride, methyl aluminum sesquibromide, ethyl aluminum sesquichloride, ethyl aluminum sesquibromide, ethyl aluminum ses-quiiodide, n-propyl aluminum sesquichloride, n-propyl aluminum sesquibromide, isobutyl aluminum sesquichloride, isobutyl aluminum sesquiiodide, n-hexyl aluminum sesquiiodide, n-decyl aluminum sesquichloride, n-dodecyl aluminum sesquibromide, and sec-eicosyl aluminum sesquichloride.

9. The process of claim 8 wherein the alkyl aluminum halide is selected from the group consisting of diethyl aluminum chloride and diisobutyl aluminum chloride.

10. A single-step process for the ring alkylation of at least one N-alkyl-N′-phenyl-phenylenediamine selected from the group consisting of N-(1,3-dimethylbutyl)-N′-phenyl-p-phenylenediamine and N-1isopropyl-N′-phenyl-p-phenylenediamine with at least one olefin selected from the group consisting of hydrocarbon acyclic monoolefins comprising from 2 to about 50 carbon atoms, cyclic olefins comprising from 5 to 10 carbon atoms, and aryl-substituted monoolefins comprising from 8 to 20 carbon atoms, wherein from about 0.5 mole equivalent to 8 mole equivalents of olefin are added for each mole of N-alkyl-N′-phenyl-phenylenediamine comprising wherein the single step of the process comprises heating a mixture of the N-alkyl-N′-phenyl-phenylenediamine(s) and olefin(s) in the presence of a catalytic amount of at least one alkyl aluminum halide selected from the group consisting of diethyl aluminum chloride and diisobutyl aluminum chloride at a temperature of from about 140 to about 240° C. in a sealed vessel for from about one to about 30 hours.

11. The process of claim 2 wherein from about 0.5 mole equivalent to 8 mole equivalents of olefin are added for each mole of N-alkyl-N′-phenyl-phenylenediamine.

12. The process of claim 2 wherein the alkyl aluminum halide is selected from the group consisting of dimethyl aluminum bromide, diethyl aluminum bromide, diethyl aluminum chloride, di-n-propyl aluminum chloride, diisobutyl aluminum iodide, diisobutyl aluminum chloride, diisoamyl aluminum chloride, di-n-dodecyl aluminum chloride, dieicosyl aluminum bromide, methyl aluminum dichloride, ethyl aluminum dichloride, ethyl aluminum dibromide, n-propyl aluminum dichloride, isobutyl aluminum dibromide, n-hexyl aluminum dibromide, sec-decyl aluminum di-iodide, n-dodecyl aluminum dichloride, n-eicosyl aluminum dibromide, methyl aluminum sesquichloride, methyl aluminum sesquibromide, ethyl aluminum sesquichloride, ethyl aluminum sesquibromide, ethyl aluminum ses-quiiodide, n-propyl aluminum sesquichloride, n-propyl aluminum sesquibromide, isobutyl aluminum sesquichloride, isobutyl aluminum sesquiiodide, n-hexyl aluminum sesquiiodide, n-decyl aluminum sesquichloride, n-dodecyl aluminum sesquibromide, and sec-eicosyl aluminum sesquichloride.

13. The process of claim 12 wherein the alkyl aluminum halide is selected from the group consisting of diethyl aluminum chloride and diisobutyl aluminum chloride.