Synthesis Of Some Six-membered Heterocyclic Compounds Under Ultrasound

Ultrasound has been widely used in organic synthesis. Compared with traditional method, the main advantages of ultrasound are simple-operation, shorter reaction time, higher yield and milder condition.Heterocycle compounds are most important divisions of organic chemistry. Most of the heterocycles which isolated from nature product or synthesized possess biologically activities. Heterocycle compounds had been widely used in pharmaceutical and medicinal chemistry. Some applications of ultrasound in the synthesis of heterocycle compounds are summarized recently.A series of benzoxanthene derivatives were synthesized via three-component condensation of aromatic aldehyde, 2-naphthol and 5,5-dimethyl-1,3-cyclohexanedione in water under ultrasound. Synthesis of 2,2'-arylmethylene bis(3-hydroxy-5,5-dimethyl-2-cyclohexene-1-one) derivatives via the condensation of aromatic aldehydes and 5,5-dimethyl-1,3-cyclohexanedione in water under ultrasound. The procedures described are simple, mild, and efficient.The condensation of 1,2-diarylethanedione and 1,2-phenylenediamine was carried out in several minutes and offered 2,3-diarylquinoxaline in high yields.