The author of 《Acid-Catalyzed Condensation of o-Phenylenediamines and o-Aminophenols with α-Oxodithioesters: A Divergent and Regioselective Synthesis of 2-Methylthio-3-aryl/Heteroarylquinoxalines and 2-Acylbenzoxazoles》 were Kiran, Kuppalli R.; Swaroop, Toreshettahally R.; Sukrutha, Kodipura P.; Shruthi, Jeegundipattana B.; Anil, Seegehally M.; Rangappa, Kanchugarakoppal S.; Sadashiva, Maralinganadoddi P.. And the article was published in Synthesis in 2019. Formula: C6H6OS The author mentioned the following in the article:
O-Phenylenediamines and o-aminophenols were reacted with α-oxodithioesters in a highly regioselective fashion to give 2-methylthio-3-aryl/heteroarylquinoxalines I (R = C6H5, 2-thienyl, 4-FC6H4, etc.; R1 = H, 6-Br, 6-CF3, 6-NO2) and 2-acylbenzoxazoles II (R = C6H5, 4-OMeC6H4, 4-ClC6H4, etc.; R1 = H, 5-Me, 5-NO2) in 55-94% and 45-86%, resp., in the presence of p-toluenesulfonic acid catalyst. Control experiments involving reaction of aniline with a α-oxodithioester indicated that the thiocarbonyl group is more reactive than the carbonyl group. Based on this, probable mechanisms for the formation of quinoxalines and benzoxazoles are given. Biol. targets of the quinoxalines and benzoxazoles were identified by bioinformatics. It was found that quinoxalines have good binding affinity with human dual-specificity tyrosine-phosphorylation-regulated kinase 1A and benzoxazoles with human carboxylesterase. After reading the article, we found that the author used 1-Thiophen-2-yl-ethanone(cas: 88-15-3Formula: C6H6OS)
1-Thiophen-2-yl-ethanone(cas: 88-15-3) belongs to thiophenes. Reflecting their high stabilities, thiophenes arise from many reactions involving sulfur sources and hydrocarbons, especially unsaturated ones. Thiophenes are classically prepared by the reaction of 1,4-diketones, diesters, or dicarboxylates with sulfidizing reagents such as P4S10 such as in the Paal-Knorr thiophene synthesis. Formula: C6H6OS
Referemce:
Benzothiophene – Wikipedia,
Benzothiophene | C8H6S – PubChem