1,2-Bis(n-butylthio) (CAS NO.: 53663-38-0), which is also known as Benzene, o-bis(butylthio)-, could be produced through the following synthetic routes.

A. Cuprous n-butylmercaptide. A mixture of 42.9 g. (0.30 mole) of freshly prepared cuprous oxide, 61.3 g. (0.68 mole)of 1-butanethiol, and 750 ml. of 95% ethanol is ed under reflux with mechanical stirring until the orange or red color of the cuprous oxide is completely changed to the white color of the cuprous n-butylmercaptide. The product is collected by filtration, washed several times with 95% ethanol, and dried in a vacuum. The yield is 91.6 g., essentially quantitative.

B. 1,2-Bis(n-butylthio)benzene (CAS NO.: 53663-38-0). In a 1-l., round-bottomed, three-necked flask fitted with a reflux condenser, a mechanical stirrer, and a thermometer which reaches into the reaction mixture is placed a solution of 59.0 g. (0.25 mole) of o-dibromobenzene in a mixture of 250 ml. of quinoline and 80 ml. of pyridine. To this solution is added 84.0 g. (0.55 mole) of cuprous n-butylmercaptide, and the mixture is stirred and heated under reflux for 3.5 hours. Heating is stopped and the reaction mixture is allowed to cool to about 100°. It is then poured into a stirred mixture of 1500 g. of ice and 400 ml. of concentrated hydrochloric acid; occasional stirring is continued for about 2 hours. The aqueous part is then decanted from the dark brown, gummy residue and is extracted twice with 400 ml. portions of ether. The ether extract is added to the residue, and the resulting mixture is stirred for about 5 minutes. The ether solution is then decanted from the residue and is filtered. The residue is extracted twice more with 400-ml. portions of ether. The combined ether extract is washed twice with 100-ml. portions of 10% hydrochloric acid, once with water, and twice with 100-ml. portions of concentrated ammonia. After a final wash with water, the ether solution is dried over anhydrous potassium carbonate. The potassium carbonate is collected on a filter, and the ether is removed from the filtrate by distillation. The remaining brown oil is distilled in vacuum, giving a pale orange oil, b.p. 123–124°/0.3 mm., n_D25 1.5684. The yield is 46.5–56.0 g. (73–87%).