[presh977]

Hi,

I'm interested in the synthesis of phenothiazine, but I haven't been able to turn up any good resources. Organic chem isn't really my forte, so I was wondering if anyone had any ideas.

I thought perhaps using 2-aminobenzenethiol and 1,2-dibromobenzene, something of that nature. Any suggestions would be welcome.

I know you can buy it, I am hoping to decorate with tert-butyl groups eventually.

Cheers

[Andy]

you can use copper-powderand K2CO3 in DMF . 

[Custos]

Heating diphenylamine and sulfur with iodine catalyst is the classic synthesis of phenothiazine:

Phenothiazine was synthesized by refluxing elementary sulphur with diphenylamine in the molar ratio of 2:1.3 respectively, for 1 h at 180 degC in 1,2-dichlorobenzene under an atmosphere of nitrogen, 1% (w/w) iodine being added as a catalyst. The evolved hydrogen sulphide was trapped in an aqueous solution of FeCl3 (1m). The solvent was removed by distillation, the excess diphenylamine precipitated in anhydrous ethereal solution by dry HCl gas and the phenothiazine recrystallized twice from aqueous ethanol to give light yellow crystals, m.p. 181-183 degC.

[presh977]

Hi,

Thank you for your help. I have had more of a look around, and it seems that the diphenylamine method will not work for what I have in mind. I want to put tert-butyl groups on the rings, but unfortunately then the reaction no longer proceeds. I have found one method that uses a microwave, but I'm not sure how keen the neighbouring lab will be with me using it, as the reaction liberates H2S.

Thanks again.