ChemicalBook CAS DataBase List 4-Hydroxythiobenzamide

4-Hydroxythiobenzamide synthesis

4synthesis methods

Product Name:4-Hydroxythiobenzamide
CAS Number:25984-63-8
Molecular formula:C7H7NOS
Molecular Weight:153.2

4-Hydroxythiobenzamide is an important intermediate of Febuxostat, a new anti-gout drug. A patent discloses a method for preparing p-hydroxythiobenzamide. Specifically, a certain amount of water, p-cyanophenol, sodium hydrosulfide, and secondary amine are mixed evenly. At a specific temperature, an organic weak acid is added dropwise. After the reaction is completed, the mixture is filtered, and the filter cake is dried to obtain 4-Hydroxythiobenzamide.

767-00-0 Synthesis

767-00-0
558 suppliers
$6.00/25g

25984-63-8
477 suppliers
$8.00/10g

Yield:25984-63-8 97.57%

Reaction Conditions:

Stage #1: 4-cyanophenolwith sodium hydrogensulfide in water at 20; for 0.5 h;
Stage #2: with hydrogen sulfide at 70; under 2068.65 - 2896.11 Torr; for 5.91667 - 6 h;

Steps:

1 4-hydroxybenzene carbothioamide

A mixture of 4-Cyanophenol (50.0 g, 0.42 mol), and NaSH (15.5 g, 0.21 mol) in distilled water (125 mL) was stirred at room temperature for 30 minutes. The mixture was then put under a vacuum, flushed with H₂S, and the pressure was brought to 40-50 psi for a period of a few minutes. The mixture was then heated to 70° C. and stirred for 40-45 minutes. The mixture was stirred vigorously at 70° C. under constant pressure of 56 psi for 5 hours and 15 minutes. The H₂S pressure was removed and the reaction was cooled to room temperature. The reaction was neutralized to pH 5-7 with 2 M HCl (66 mL). The product was filtered, and the filter cake washed with distilled water (2*50 mL), and dried under a vacuum at 80-85° C. for 22 hours to provide 62.74 g (97.57%) desired product.

References:

US2005/75503,2005,A1 Location in patent:Page/Page column 3

619-57-8 Synthesis