PREPARATION METHOD OF SUBSTITUTED PRIMARY AMINE

Abstract

A preparation method of substituted primary amine is disclosed. The preparation method uses cyanophenyl and a derivative thereof as raw materials, nanoporous palladium as a catalyst, and H.sub.2 as a hydrogen source, and conducts selective hydrogenation to prepare the substituted primary amine. The molar concentration of the cyanophenyl and the derivative thereof in the solvent is 0.01-2 mmol/mL, and the molar ratio of the cyanophenyl to the derivative thereof to the catalyst is 1: 0.01-1: 0.5. The size of a pore framework of the nanoporous palladium is 1 nm-50 nm. The pressure of the H.sub.2 is 0.1-20.0 MPa. The obtained product has high selectivity; the present invention has mild reaction conditions, does not need any additive, and has simple operation and post-processing and good catalyst reproducibility. After repeatedly used, the catalytic activity of the present invention is not significantly reduced, thereby providing the possibility of realizing industrialization.

Claims

1. A preparation method of substituted primary amine, using cyanophenyl and a derivative thereof as raw materials, nanoporous palladium as a catalyst, and H.sub.2 as a hydrogen source, and conducting selective hydrogenation to prepare the substituted primary amine, wherein a synthetic route is shown as follows: ##STR00012## reaction temperature is 0 C. - 150 C., and reaction time is 12 h - 36 h; R is aryl or alkyl; the solvent is one or a mixture of more than one of water, ether, acetonitrile, dimethyl sulfoxide, dioxane, triethylamine, tetrahydrofuran, toluene, ethanol, isopropanol, chloroform, methylene chloride, acetone and N,N-dimethylformamide, wherein the molar concentration of the cyanophenyl and the derivative thereof in the solvent is 0.01-2 mmol/mL, and the molar ratio of the cyanophenyl to the derivative thereof to the catalyst is 1: 0.01-1: 0.5.

2. The preparation method of substituted primary amine according to claim 1, wherein the size of a pore framework of the nanoporous palladium is 1 nm-50 nm.

3. The preparation method of substituted primary amine according to claim 1, wherein the pressure of the H.sub.2 is 0.1-20.0 MPa.

Description

DESCRIPTION OF DRAWINGS

[0014] FIG. 1 is a .sup.1H NMR spectrum diagram of benzylamine in embodiments 1 and 2.

[0015] FIG. 2 is a .sup.1H NMR spectrum diagram of 4-methylbenzylamine in embodiments 3 and 4.

[0016] FIG. 3 is a .sup.1H NMR spectrum diagram of phenethylamine in embodiments 5 and 6.

[0017] FIG. 4 is a .sup.1H NMR spectrum diagram of 4-methoxyphenethylamine in embodiments 7 and 8.

[0018] FIG. 5 is a .sup.1H NMR spectrum diagram of n-hexylamine in embodiments 9 and 10.

DETAILED DESCRIPTION

[0019] Specific embodiments of the present invention are further described below in combination with accompanying drawings and the technical solution.

[0020] The preparation method of the substituted primary aliphatic amine in the present invention has highest selectivity and reaction yield of 100% and 93% respectively, and does not need any additive in the reaction. The selected catalyst has good catalytic reaction reproducibility and simple operation and post-processing. After repeatedly used, the catalytic activity of the catalyst is not significantly reduced, thereby providing favorable conditions for the industrial production.

Embodiment 1: Synthesis of Benzylamine

[0021] A substrate benzonitrile (51.6 mg, 0 5 mmol) and hydrogen (5 bar) are added to an ethanol (3 mL) solvent with PdNPore (1.6 mg, 3 mol %) catalyst; the mixture is placed in an oil bath at 50 C. to react for 24 h; column chromatography is conducted (silica gel, 200-300 meshes; developing agent, methanol and ethyl acetate) to obtain 48.8 mg of benzylamine, with yield of 93% and selectivity of 97%. Under the same conditions, if Pd/C is used as the catalyst, the yield of the benzylamine is only 65%, and the selectivity is 72%.

##STR00002##

.sup.1H NMR (400 MHz, CDCl.sub.3) : 7.35-7.20 (m, 5H), 3.84 (s, 2H), 1.54 (br, 2H).

Embodiment 2: Synthesis of Benzylamine

[0022] A substrate benzonitrile (30.9 mg, 0 3 mmol) and hydrogen (5 bar) are added to an N,N-dimethylformamide (3 mL) solvent with PdNPore (5.4 mg, 10 mol %) catalyst; the mixture is placed in an oil bath at 30 C. to react for 20 h; column chromatography is conducted (silica gel, 200-300 meshes; developing agent, methanol and ethyl acetate) to obtain 28.9 mg of benzylamine, with yield of 90% and selectivity of 96%.

##STR00003##

.sup.1H NMR (400 MHz, CDCl.sub.3) : 7.35-7.20 (m, 5H), 3.84 (s, 2H), 1.54 (br, 2H).

Embodiment 3: Synthesis of 4-methylbenzylamine

[0023] A substrate 4-methylbenzonitrile (58.6 mg, 0.5 mmol) and hydrogen (5 bar) are added to an ethanol (3 mL) solvent with PdNPore (1.6 mg, 3 mol %) catalyst; the mixture is placed in an oil bath at 50 C. to react for 24 h; column chromatography is conducted (silica gel, 200-300 meshes; developing agent, methanol and ethyl acetate) to obtain 53.9 mg of 4-methylbenzylamine, with yield of 89% and selectivity of 98%. Under the same conditions, if Pd/C is used as the catalyst, the yield of the 4-methylbenzylamine is only 69%, and the selectivity is 78%.

##STR00004##

.sup.1H NMR (CDCl.sub.3, 400 MHz) : 7.20 (d, J=8Hz, 2H), 7.14 (d, J=8Hz, 2H), 3.83 (s, 2H), 2.34 (s, 3H), 2.06 (br, 2H).

Embodiment 4: Synthesis of 4-methylbenzylamine

[0024] A substrate 4-methylbenzonitrile (58.6 mg, 0.5 mmol) and hydrogen (5 bar) are added to an acetonitrile (5 mL) solvent with PdNPore (1.1 mg, 2 mol %) catalyst; the mixture is placed in an oil bath at 50 C. to react for 24 h; column chromatography is conducted (silica gel, 200-300 meshes; developing agent, methanol and ethyl acetate) to obtain 50.3 mg of 4-methylbenzylamine, with yield of 83% and selectivity of 96%.

##STR00005##

.sup.1H NMR (CDCl.sub.3, 400 MHz) : 7.20 (d, J=8Hz, 2H), 7.14 (d, J=8Hz, 2H), 3.83 (s, 2H), 2.34 (s, 3H), 2.06 (br, 2H).

Embodiment 5: Synthesis of Phenethylamine

[0025] A substrate phenylacetonitrile (58.58 mg, 0.5 mmol) and hydrogen (5 bar) are added to an ethanol (3 mL) solvent with PdNPore (1.6 mg, 3 mol %) catalyst; the mixture is placed in an oil bath at 70 C. to react for 24 h; column chromatography is conducted (silica gel, 200-300 meshes; developing agent, methanol and ethyl acetate) to obtain 53.3 mg of phenethylamine, with yield of 88% and selectivity of 100%. Under the same conditions, if Pd/C is used as the catalyst, the yield of the phenethylamine is only 40%, and the selectivity is 45%.

##STR00006##

.sup.1H NMR (400 MHz, CDCl.sub.3) : 7.29-7.24 (m, 2H), 7.21-7.14 (m, 3H), 2.89 (t, J=7.2Hz, 2H), 2.78 (t, J=7.2Hz, 2H), 1.59 (br, 2H).

Embodiment 6: Synthesis of Phenethylamine

[0026] A substrate phenylacetonitrile (58.58 mg, 0.5 mmol) and hydrogen (5 bar) are added to an ethanol (5 mL) solvent with PdNPore (2.7 mg, 5 mol %) catalyst; the mixture is placed in an oil bath at 70 C. to react for 19 h; column chromatography is conducted (silica gel, 200-300 meshes; developing agent, methanol and ethyl acetate) to obtain 52.71 mg of phenethylamine, with yield of 87% and selectivity of 100%.

##STR00007##

.sup.1H NMR (400 MHz, CDCl.sub.3) : 7.29-7.24 (m, 2H), 7.21-7.14 (m, 3H), 2.89 (t, J=7.2Hz, 2H), 2.78 (t, J=7.2Hz, 2H), 1.59 (br, 2H).

Embodiment 7: Synthesis of 4-Methoxyphenethylamine

[0027] A substrate 4-methoxybenzeneacetonitrile (73.59 mg, 0 5 mmol) and hydrogen (5 bar) are added to an ethanol (3 mL) solvent with PdNPore (1.6 mg, 3 mol %) catalyst; the mixture is placed in an oil bath at 70 C. to react for 24 h; column chromatography is conducted (silica gel, 200-300 meshes; developing agent, methanol and ethyl acetate) to obtain 62.8 mg of 4-methoxyphenethylamine, with yield of 83% and selectivity of 100%.

##STR00008##

.sup.1H NMR (400 MHz, CDCl.sub.3) : 7.06 (d, J=8Hz, 2H), 6.80 (d, J=8Hz, 2H), 3.77 (s, 3H), 2.84 (t, J=8Hz, 2H), 2.71 (t, J=8Hz, 2H).

Embodiment 8: Synthesis of 4-methoxyphenethylamine

[0028] A substrate 4-methoxybenzeneacetonitrile (73.59 mg, 0 5 mmol) and hydrogen (5 bar) are added to an acetonitrile (5 mL) solvent with PdNPore (2.7 mg, 5 mol %) catalyst; the mixture is placed in an oil bath at 50 C. to react for 16 h; column chromatography is conducted (silica gel, 200-300 meshes; developing agent, methanol and ethyl acetate) to obtain 60.48 mg of 4-methoxyphenethylamine, with yield of 80% and selectivity of 98%.

##STR00009##

.sup.1H NMR (400 MHz, CDCl.sub.3) : 7.06 (d, J=8Hz, 2H), 6.80 (d, J=8Hz, 2H), 3.77 (s, 3H), 2.84 (t, J=8Hz, 2H), 2.71 (t, J=8Hz, 2H).

Embodiment 9: Synthesis of n-hexylamine

[0029] A substrate hexanenitrile (48.58 mg, 0 5 mmol) and hydrogen (5 bar) are added to an ethanol (3 mL) solvent with PdNPore (1.6 mg, 3 mol %) catalyst; the mixture is placed in an oil bath at 50 C. to react for 24 h; column chromatography is conducted (silica gel, 200-300 meshes; developing agent, methanol and ethyl acetate) to obtain 44.0 mg of n-hexylamine, with yield of 87% and selectivity of 100%.

##STR00010##

.sup.1H NMR (400 MHz, CDCl.sub.3) : 2.60 (t, J=7.2Hz, 2H), 1.77 (br, 2H), 1.52-1.46 (m, 2H), 1.36-1.28 (m, 6H), 0.88 (t, J=6.8Hz, 3H).

Embodiment 10: Synthesis of n-hexylamine

[0030] A substrate hexanenitrile (48.58 mg, 0 5 mmol) and hydrogen (6 bar) are added to an ethanol (3 mL) solvent with PdNPore (2.7 mg , 5 mol %) catalyst; the mixture is placed in an oil bath at 80 C. to react for 20 h; column chromatography is conducted (silica gel, 200-300 meshes; developing agent, methanol and ethyl acetate) to obtain 45.54 mg of n-hexylamine, with yield of 90% and selectivity of 100%.

##STR00011##

.sup.1H NMR (400 MHz, CDC.sub.3) 6: 2.60 (t, J=7.2 Hz, 2H), 1.77 (br, 2H), 1.52-1.46 (m, 2H), 1.36-1.28 (m, 6H), 0.88 (t, J=6.8Hz, 3H).