# US 6,720,426 B2 · Process for producing 2-(4-pyridyl)ethanethiol

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- Number: US 6,720,426 B2
- Document ID: US6720426B2
- Status: Granted
- Kind: B2
- Application number: 10/435,375
- Filed: 2003-05-12
- Published: 2003-10-16
- Granted: 2004-04-13
- Earliest claimed: 2000-11-21
- Assignees: Mitsubishi Chemical Corporation
- Inventors: Hideto Hayashi; Koichi Hayashi
- Web page: https://patentgrep.com/patent/US6720426B2

## CPC

- C07D 213/32: Sulfur atoms
- C07C 37/20: using aldehydes or ketones
- C07C 39/16: Bis-(hydroxyphenyl) alkanes; Tris-(hydroxyphenyl)alkanes
- C07D: HETEROCYCLIC COMPOUNDS (macromolecular compounds C08)
- C07C: ACYCLIC OR CARBOCYCLIC COMPOUNDS

## Abstract

An object of the present invention is to provide a process for producing 2-(4-pyridyl)ethanethiol easily. According to the invention, 4-vinylpyridine is reacted with thiourea in an aqueous medium containing an acid to form a solution containing an isothiuronium salt and then the solution is made alkaline to convert the isothiuronium salt into 2-(4-pyridyl)ethanethiol.

## Claims

### Claim 1

A process for producing 2-(4-pyridyl)ethanethiol comprising a step of reacting 4-vinylpyridine with thiourea in an aqueous medium containing an acid to form a solution containing an isothiuronium salt and a successive step of making the solution alkaline to convert the isothiuronium salt into 2-(4-pyridyl)ethanethiol.

### Claim 2 (depends on 1)

The process for producing 2-(4-pyridyl)ethanethiol according to claim 1, wherein the acid is p-toluenesulfonic acid.

### Claim 3 (depends on 1)

The process for producing 2-(4-pyridyl)ethanethiol according to claim 1, wherein the acid is sulfuric acid.

### Claim 4 (depends on 1)

The process for producing 2-(4-pyridyl)ethanethiol according to claim 1, wherein the solution containing an isothiuronium salt is made alkaline by adding ammonia water to the solution.

### Claim 5 (depends on 1)

The process for producing 2-(4-pyridyl)ethanethiol according to claim 1, wherein the solution containing an isothiuronium salt is maintained at a temperature of 50° C. or lower at the time when the solution is made alkaline.

### Claim 6 (depends on 1)

The process for producing 2-(4-pyridyl)ethanethiol according to claim 1, wherein the solution containing an isothiuronium salt is maintained at a temperature of less than 50° C. at least until the solution reaches a neutral point and then warmed to a temperature of 50° C. or higher at the time when the solution is made alkaline.