REACTION COMPOSITION AND REACTION SYSTEM USING THIS

Abstract

An aromatic nitro compound has a structure in which a nitro group and a halogen atom, in a separated state, are directly bonded as substituents to the ring structure of the same ring; a reaction composition is provided which, in a hydrogenation reaction of the nitro group of said aromatic nitro compound, allows selectively hydrogenating the nitro group, and sufficiently reducing the separation of the halogen atom from the ring; also provided is a reaction system that uses this reaction composition. This reaction composition includes a solvent, and a catalyst which, with the aforementioned aromatic nitro compound as reactant, is used in a hydrogenation reaction of at least one of the one or more nitro groups of said reactant. The catalyst includes a carrier, and Fe oxide particles and Pt particles supported by the carrier.

Claims

1. A reaction composition comprising a catalyst which is used in a hydrogenation reaction of at least one among one or more nitro groups present in a reactant to an amino group, the reactant being an aromatic nitro compound having a structure in which one or more nitro groups and one or more halogen atoms are directly bonded as substituents to a ring skeleton of the same ring while separated from each other, and an organic solvent, wherein: the catalyst comprises a support, and Pt particles and Fe oxide particles supported on the support, and the constituent element of the organic solvent satisfies the following condition of the equation (1):
0.00%{100(Vh/Vs)}10.00%(1) in the equation (1), Vh being a volume (L) of an introduced water other than the yielded water, and Vs being a volume (L) of the organic solvent which can dissolve at least a part of the reactant.

2. The reaction composition according to claim 1, further comprising the aromatic nitro compound.

3. The reaction composition according to claim 2, further comprising an aromatic amine obtained by the hydrogenation reaction of the aromatic nitro compound as a reaction product and having at least one amino group.

4. The reaction composition according claim 1, wherein the constituent element of the organic solvent satisfies the following condition of the equation (2):
1.00%{100(Vh/Vs)}5.00%(2)

5. The reaction composition according to claim 1, further comprising a dehydrating agent.

6. A reaction system comprising a reaction vessel which can accommodate at least one of the reaction compositions according to claim 1 as a reactant.

7. The reaction composition according to claim 2, wherein the constituent element of the organic solvent satisfies the following condition of the equation (2):
1.00%{100(Vh/Vs)}5.00%(2)

8. The reaction composition according to claim 3, wherein the constituent element of the organic solvent satisfies the following condition of the equation (2):
1.00%{100(Vh/Vs)}5.00%(2)

9. The reaction composition according to claim 2, further comprising a dehydrating agent.

10. The reaction composition according to claim 3, further comprising a dehydrating agent.

11. The reaction composition according to claim 4, further comprising a dehydrating agent.

12. A reaction system comprising a reaction vessel which can accommodate at least one of the reaction compositions according to claim 2 as a reactant.

13. A reaction system comprising a reaction vessel which can accommodate at least one of the reaction compositions according to claim 3 as a reactant.

14. A reaction system comprising a reaction vessel which can accommodate at least one of the reaction compositions according to claim 4 as a reactant.

15. A reaction system comprising a reaction vessel which can accommodate at least one of the reaction compositions according to claim 5 as a reactant.

Description

EXAMPLE

[0096] In the following, the present invention is explained in detail by referring working examples, but the present invention is not limited by the following working examples.

<Preparation of Reaction Composition>

Example 1

[0097] As the catalyst, a catalyst where the Pt particles and the Fe oxide particles were carried on a carbon support (trade name NE-01M02, content of Pt: 1.0 wt %, content of Fe: 0.20 wt % available from N. E. CHEMCAT Co. (hereinafter referred to as Pt-FeOx/C as necessary)) was prepared.

[0098] In the Pt-FeOx/C, the carbon support is an activated carbon (specific surface area based on BET measurement is 900: m.sup.2/g), and the Fe oxide particles are Fe.sub.2O.sub.3 as a main component (Fe.sub.2O.sub.3 is approximately 100% based on XPS analysis).

[0099] As the organic solvent, a commercially available toluene was prepared.

[0100] A reaction composition was obtained by mixing 127.0 mg (water content: 0.141 mL) of Pt-FeOx/C powder, and 10 mL of toluene (organic solvent).

Example 2

[0101] The reaction composition of Example 2 was prepared in the same preparation conditions and the same raw materials as Example 1 except that 127.0 mg (water content: 0.141 mL) of the same powder of Pt-FeOx/C catalyst as in Example 1 was subjected to drying treatment (using a dryer, holding in air at 300 C. for 15 minutes) to adjust the water content measured with a moisture content meter to 0 mL was used.

Example 3

[0102] The reaction composition of Example 3 was prepared in the same preparation conditions and the same raw materials as Example 1 except that the reaction composition was prepared by adding the dehydrating agent to 127.0 mg (water content: 0.141 mL) of the same powder of Pt-FeOx/C catalyst as in Example 1, and then adding 10 mL of toluene.

[0103] As the dehydrating agent, 2 g of commercially available zeolite having a structure code LTA type (Molecular Sieves 4 A) was used. The amount of the dehydrating agent is enough to dehydrate all moisture contained in the Pt-FeOx/C catalyst.

(Example 4) to (Example 9)

[0104] The reaction compositions of Example 4 to Example 9 were prepared in the same preparation conditions and the same raw materials as Example 1 except that the value of {100(Vh/Vs)} was changed to the value shown in Table 1.

Comparative Example 1

[0105] The reaction composition of Comparative Example 1 was prepared in the same preparation conditions and the same raw materials as in Example 1 except that 1 mL of water was added to the same reaction composition as Example 1.

<Hydrogenation Reaction>

[0106] The hydrogenation reaction (hydrogenation reaction of nitro group) represented by the following reaction scheme (C1-11) was achieved by using the reaction compositions of Example 1 to Example 3 and Comparative Example 1.

##STR00005##

[0107] Here, in the hydrogenation reaction represented by the reaction scheme (C1-11), 2-bromo-5-nitropyridine represented by the formula (C1-1) has a heterocyclic structure having an N atom. Compared to 2-bromo-5-nitrobenzene which has a structure in which the N atom in this heterocyclic ring is replaced with a C atom, 2-bromo-5-nitropyridine is a reactant which promotes not only the main hydrogenation reaction of the nitro group (main product being 5-amino-2-bromopyridine represented by the formula (C1-2)), but also promotes easily the side reaction of the debromination reaction (by-product being 3-aminopyridine represented by the formula (C1-3).

(Reaction Conditions)

[0108] Reactant: 2.5 mmol of 2-Bromo-5-nitrobenzene represented by the formula (C1-1)

[0109] Pressure of hydrogen: 0.6 MPa

[0110] Reaction temperature: 50 C. (Example 1, Example 2, Examples 4 to Example 9), 100 C. (Example 3, Comparative Example 1) Reaction time: 5 hours

[0111] The results obtained for the reaction compositions of Examples 1 to 9 and Comparative Example 1 to Comparative Example 9 are shown in Table 1 and Table 2.

TABLE-US-00001 TABLE 1 Vh Vs Selectivity % Selectivity % Water Org. Solvent 100 5-amino- 3-aminopyridine Catalyst volume/ (Toluen) (Vh/Vs) Conversion 2-bromopyridine by-product structure mL volume/mL % % main product (DeBr body) Ex.1 PtFeOx/C 0.141 10.0 1.41 100 81.5 18.5 Ex.2 PtFeOx/C 0.000 10.0 0.00 100 88.5 11.5 Ex.3 PtFeOx/C 0.000 10.0 0.00 100 86.0 14.0 Ex.4 PtFeOx/C 0.050 10.0 0.50 100 81.9 18.1 Ex.5 PtFeOx/C 0.100 10.0 1.00 100 82.9 17.1 Ex.6 PtFeOx/C 0.136 10.0 1.36 100 82.0 18.0 Ex.7 PtFeOx/C 0.200 10.0 2.00 100 81.0 19.0 Ex.8 PtFeOx/C 0.300 10.0 3.00 100 81.8 18.2 Ex.9 PtFeOx/C 0.460 10.0 4.60 100 80.3 19.7 Com.Ex.1 PtFeOx/C 1.141 10.0 11.41 100 21.5 78.5 Com.Ex.2 Pt/C 0.113 10.0 1.13 100 48.9 51.1

[0112] From the results shown in Table 1, when the reaction compositions of Example 1 to Example 9 which satisfy the constitution of the present invention are compared with the reaction composition of Comparative Example 1, it has been clear that the debromination reaction to 3-aminopyridine represented by the formula (C1-3) was sufficiently reduced, and the selectivity of the desired 5-amino-2-bromopyridine represented by the formula (C1-2) was improved.

[0113] From the aforementioned results, it has been clear that, in a nitro group hydrogenation reaction of an aromatic nitro compound having a structure in which nitro groups and halogen atoms are directly bonded as substituents to a ring skeleton of the same ring while separated from each other, the reaction composition of the present examples is capable of selectively hydrogenating the nitro groups and sufficiently reducing the removal of the halogen atoms from the ring.

INDUSTRIAL APPLICABILITY

[0114] The reaction composition of the present invention has the catalyst activities that, in a nitro group hydrogenation reaction of an aromatic nitro compound (aromatic halogen nitro compound) having a structure in which nitro groups and halogen atoms are directly bonded as substituents to a ring skeleton of the same ring while separated from each other, is capable of selectively hydrogenating the nitro groups and sufficiently reducing the removal of the halogen atoms from the ring.

[0115] Therefore, the present invention contributes to the development of efficient mass production technology of the aromatic halogen amine which is an important raw material of medicines, dyes, insecticides and herbicides, and further contributes to the development of the industries of pharmaceuticals, dyes, insecticides, herbicides.