# US 11,439,985 B2 · Nitration of benzene

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 11,439,985 B2
- Document ID: US11439985B2
- Status: Granted
- Kind: B2
- Application number: 16/769,959
- Filed: 2018-12-05
- Published: 2020-12-10
- Granted: 2022-09-13
- Earliest claimed: 2017-12-07
- Assignees: Council of Scientific and Industrial Research
- Applicants: Council of Scientific & Industrial Research
- Inventors: Shubhangi Bhalchandra Umbarkar; Atul Balasaheb Kulal; Mohan Keraba Dongare
- Web page: https://patentgrep.com/patent/US11439985B2

## CPC

- B01J 23/30: Tungsten
- B01J 37/0236: {Drying, e.g. preparing a suspension, adding a soluble salt and drying}
- C07C 201/08: by substitution of hydrogen atoms by nitro groups
- C07C 205/06: having nitro groups bound to carbon atoms of six-membered aromatic rings
- B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- C07C: ACYCLIC OR CARBOCYCLIC COMPOUNDS

## Abstract

The present invention discloses a process for nitration of benzene. More particularly, the present invention discloses an efficient, environmental friendly process for the nitration of benzene using a modified solid acid catalyst.

## Claims

### Claim 1

A benzene nitration catalyst comprising hydrophobic solid acid WO3/SiO2 grafted with an organosilane selected from a C2 to C10 alkyl trialkoxysilane.

### Claim 2 (depends on 1)

The benzene nitration catalyst of claim 1, wherein the alkoxy in the C2 to C10 alkyl trialkoxysilane is methoxy, ethoxy or propoxy.

### Claim 3

A process for preparing a benzene nitration catalyst comprising the steps of:
a. dispersing 20% WO3/SiO2 in dry toluene to form a mixture:
b. adding an organosilane selected from an alkyl trialkoxysilane to the mixture of step a;
c. heating the resultant mixture of step b with constant mixing to obtain a powder and
d. drying the resultant powder of step c to obtain the benzene nitration catalyst.

### Claim 4 (depends on 3)

The process of claim 3, wherein the a ratio of WO3/SiO2 to the dry toluene is 1:4 to 1:20.

### Claim 5 (depends on 3)

The process of claim 3, wherein the benzene nitration catalyst is-comprises solid WO3/SiO2 grafted with the organosilanes.

### Claim 6 (depends on 3)

The process of claim 3, wherein in step d, the resultant powder of step c is dried in an oven.

### Claim 7

A process for nitration of benzene comprising the steps of:
a) charging benzene and a grafted hydrophobic solid acid catalyst in the range of 1:0.1 to 1:1 in a reactor flushed with nitrogen to form a reaction mixture followed by refluxing the reaction mixture at a temperature in the range of 90 to 110° C. for a period in the range of 1 to 2 hour and
b) adding nitric acid to the reaction mixture of step (a) with constantly removing by azeotropic distillation of the water formed followed by refluxing the resultant reaction mixture at a temperature in the range of 90 to 110° C. for a period in the range of 6 to 8 hour to form a mononitrobenzene.

### Claim 8 (depends on 7)

The process of claim 7, wherein the hydrophobic solid acid catalyst is WO3/SiO2.

### Claim 9 (depends on 7)

The process of claim 7, wherein conversion of the benzene to the mononitrobenzene is in the range of 50 to 100%.

### Claim 10 (depends on 7)

The process of claim 7, wherein selectivity of forming the mononitrobenzene is 100%.

### Claim 11 (depends on 7)

The process of claim 7, wherein the grafted hydrophobic solid acid catalyst does not get deactivated during the nitration of benzene and is recycled.

### Claim 12 (depends on 7)

The process of claim 7, wherein the grafted hydrophobic solid acid catalyst comprises hydrophobic solid acid WO3/SiO2 grafted with an organosilane.