1730-44-5

The invention relates to a synthesizing method of a phenothiazine compound which can serve as a medical intermediate and is shown as the formula (III) (please see the formula in the description). The method comprises the steps that at room temperature, a compound shown as the formula (I) (please see the formula in the description), a compound shown as the formula (II) (please see the formula in the description), a catalyst, a ligand, alkali and auxiliaries are added into an organic solvent, the temperature is increased to 70 DEG C to 90 DEG C, reacting under stirring is conducted for 7 hours to 10 hours, aftertreatment is conducted after reacting is finished, and then the compound shown as the formula (III) is obtained, wherein R1 and R2 are selected from H, C1-C6 alkyl groups, C1-C6 alkoxy groups and halogen separately, and X is halogen. According to the method, through usage of the appropriate reactants and comprehensive selection and synergistic promotion of the catalyst, the ligand, the alkali, the auxiliaries and the organic solvent, the target product can be obtained at a high yield, and a good application prospect and the industrialized production potential are achieved.

The invention develops a method for synthesizing phenothiazine compounds by using benzothiazole and derivatives thereof as well as 1-bromo-2-iodobenzene and derivatives thereof as raw materials and copper or copper salt/N-alkoxy-1H-pyrrolic amide system as a copper catalyst. The method is a brand-new method for synthesizing phenothiazine compounds. The method has the characteristics of low temperature, short reaction time, low solvent toxicity and wide substrate adaptability, and has wide application prospects in the aspect of preparation of medicines, pesticides and materials.

A method for the one-pot synthesis of phenothiazines from benzothiazoles and aryl ortho-dihalides was explored. Preliminary work on the mechanism of the reaction suggested that it follows a domino process, including the hydrolysis of benzothiazoles followed by C-S coupling and C-N coupling. The low loading of the catalyst system (5 mol-% for both copper and ligand), the mild experimental conditions (90 °C, 12 h), and the use of a green reaction medium make this synthesis very attractive to academia and industry. A copper-catalyzed domino reaction consisting of the hydrolysis of benzothiazoles followed by C-S and C-N couplings for the synthesis of phenothiazines from benzothiazoles and aryl ortho-dihalides is described. The low loading of the catalyst system, mild experimental conditions, and the use of polyethylene glycol as the solvent make this synthetic approach very attractive to academia and industry.