# US 5,349,103 A · Preparation of aromatic nitriles

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- Number: US 5,349,103 A
- Document ID: US5349103A
- Status: Granted
- Kind: A
- Application number: 08/184,617
- Filed: 1994-01-21
- Granted: 1994-09-20
- Earliest claimed: 1993-01-28
- Assignees: Ciba-Geigy Corporation
- Inventors: Bilge Gulec
- Web page: https://patentgrep.com/patent/US5349103A

## CPC

- C07C 231/10: from compounds not provided for in groups C07C231/02 - C07C231/08
- C07C 253/00: Preparation of carboxylic acid nitriles (of cyanogen or compounds thereof C01C3/00)
- C07C: ACYCLIC OR CARBOCYCLIC COMPOUNDS

## Abstract

A process for the preparation of a nitrile of formula ##STR1## wherein R is hydrogen, C.sub.1 -C.sub.4 alkyl or phenyl, by reaction of an aldehyde of formula ##STR2## wherein R is as defined above, with hydroxylamine sulfate and subsequent dehydration, which process comprises carrying out the reaction in propionic acid in the presence of a salt of propionic acid by heating to an external temperature in the range from 140.degree. to 165.degree. C., preferably from 150.degree. to 160.degree. C., for 2 to 6 hours, preferably for 3 to 5 hours, under atmospheric pressure, and simultaneously distilling the mixture of propionic acid and water from the system until a solution forms, and thereafter removing the mixture of propionic acid and water at 100.degree.-130.degree. C., preferably 110.degree.-120.degree. C., by vacuum distillation, and then isolating the resultant nitrile by standard procedures.

## Claims

### Claim 1

A process for the preparation of a nitrile of formula ##STR6## wherein R is hydrogen, C.sub.1 -C.sub.4 alkyl or phenyl, by reaction of an aldehyde of formula ##STR7## wherein R is as defined above, with hydroxylamine sulfate and subsequent dehydration, which process comprises carrying out the reaction in propionic acid in the presence of a salt of propionic acid by heating to an external temperature in the range from 140.degree. to 165.degree. C. for 2 to 6 hours, under atmospheric pressure and simultaneously distilling the mixture of propionic acid and water from the system until a solution forms, and thereafter removing the mixture of propionic acid and water at 100.degree.-130.degree. C. by vacuum distillation, and then isolating the resultant nitrile by standard procedures.

### Claim 2 (depends on 1)

A process according to claim 1, wherein R is in 4-position.

### Claim 3 (depends on 2)

A process according to claim 2, wherein R is tert-butyl or phenyl.

### Claim 4 (depends on 2)

A process according to claim 2, wherein R is phenyl.

### Claim 5 (depends on 1)

A process according to claim 1, wherein the propionic acid is added in an amount of 10 to 20 mol, based on 1 mol of aldehyde.

### Claim 6 (depends on 5)

A process according to claim 5, wherein the hydroxylamine sulfate is added in an amount of 0.505 to 0.55 mol based on 1 mol of aldehyde, and the sodium propionate is added in an amount of 1.05 to 1.3 mol, based on 1 mol of hydroxylamine sulfate.

### Claim 7 (depends on 1)

A process according to claim 1, wherein the reaction is carried out by heating to an external temperature in the range from 150.degree. to 160.degree. C. for 3 to 5 hours and the mixture of propionic acid and water is removed by vacuum distillation at 110.degree.-120.degree. C.