Tremarit Wander W. Germany,Wander ,W. Germany,1960
To 4.9 g of finely pulverized sodium in 50 ml of absolute benzene add dropwise with stirring 12 g of chlorobenzene in 50 ml of absolute benzene. As soon as the exothermic reaction begins, maintain the temperature by cooling between 30° and 35°C, and continue stirring for 2 to 3 hours. To the resulting phenyl sodium add dropwise 19.8 g of thioxanthene in 120 ml of absolute benzene. The slightly exothermic reaction ceases after about 1 to 1? hours.
To this newly formed 9-thioxanthyl sodium add dropwise, with stirring and cooling, 13.1 g of N-methyl-3-chloromethyl-piperidine in 30 to 40 ml of absolute benzene, then continue stirring at about 25°C for 1? hours, and heat subsequently to 40°C for 1 hour. Decompose the resulting mixture by adding carefully a small amount of water, and then extract the newly formed base from the benzene solution by means of dilute hydrochloric acid. The aqueous hydrochloric solution is made alkaline by adding dilute sodium hydroxide, and the thioxanthene base is isolated by extraction with ether. This results in 22 g of a slightly yellow, viscous base of BP 171° to 175°C/0.07 mm.
The base is acidified with alcoholic hydrochloric acid. Alcohol-ether (1:2) is then added and the hydrochloride salt is crystallized as colorless flakes melting at 211° to 213°C.