One-Pot Tandem Synthesis Of Quinazolines And 2-Heteroaromatic Benzothiazoles

Heterocyclic chemistry, which contains hundreds of compounds, is an important branch of organic chemistry. According to the statistics, the number of heterocyclic compounds occupies one third in all discovered organic compounds. Hence, heterocyclic compounds play an essential role in almost every area of organic chemistry. Heterocyclic chemistry is one of the most active fields in the study of modern chemistry, and it plays an important role in organic chemistry. Heterocyclic compounds are widely abundant in nature, according to statistics, heterocyclic compounds are nummerous at present, the number of organic compounds accounts for one third of the total. Nitrogen heterocyclic compounds usually have unique biological and pharmaceutical activities. It is easy to introduce different functional groups to modify their structure, so different chemical substances could be obtained conveniently which leads to widely apply in pharmaceutical, dye, agricultural fields.Quinazoline derivatives and 2-heteroaromatic benzothiazole derivatives show extensive biological and pharmacological activities, such as bactericidal, insecticidal, anti-virus, antihypertension, anti-tumor and other activities. Numerous quinazoline derivatives have been developed as available drugs such as fungicide Fluquinconazole, anticancer drug Iressa, antihypertensive drug prazosin hydrochloride, antimalarial drugs metronidazole, anticancer reagent PMX610 and fat acid amide hydrolase inhibitors and so on. Moreover, due to their special fluorescent qualities, they are widely applied in the field of industrial dyes, functional materials, organic fluorescent sensors.This paper mainly studied one-pot tandem reaction approach for synthesis of quinazoline compounds and 2-heteroaromatic benzothiazoles. In the second chapter, a one-pot three-component synthetic protocol to construct quinazoline derivatives via copper-catalysed procedure had been developed. We chose 2-amino benzoyl compounds and ammonium acetate as raw material, CuCl as catalyst, oxygen as oxidant, acetic acid, and reacted at 110℃ for 12 h in a variety of containing sp3 carbon solvent, which provided moderate to good yields of quinazoline compounds. In the reaction process, copper catalyst has advantages over other transition-metals catalysts, such as low price, easy preparation, high catalytic efficiency. Ammonium acetate is cheap nitrogen source. Oxygen is green, environmental-friendly. Several types of solvents act as two kinds of roles including solvent and reactant in the process, which contributes to greatly improving the reaction of atomic economy. This method is simple and efficient, and further studies on the application in synthesis of biological compounds are in progress.In the third chapter, we had developed a simple and efficient process for construction of 2-heteroaromatic benzothiazole compounds. The optimized reaction condition of this system was NIS as catalyst, TBHP (70% aqueous solution) as oxidant, acetic acid, under nitrogen, at 80℃. The scope of 2-methyl aromatic heterocyclic was investigated. Benzothiazole with different 2- methyl aromatic heterocyclic and 2-methylquinoline with different benzothiazoles both could obtain moderate yields of target products. Next we plan to carry out a series of control experiments to present a reasonable reaction mechanism, then collect the data to write an excellent paper.