Research In Synthesis Of Dihydroquinolin-2(1H)-ones By Radical Addition-Cyclization

3,4-disubstituted dihydroquinolin-2(1H)-ones are found in many pharmaceuticals and bioactive compounds, Moreover, 3,4-dihydroquinolin-2(1H)-ones are a versatile structural unit for the preparation of other important natural products. Thus, the development of a straightforward and highly efficient method for the construction of 3,4-dihydroquinolin-2(1H)-one is highly desirable. This dissertation studied three methods about the synthesis of 3,4-disubstituted dihydroquinolin-2(1H)-ones by radical addition-cyclization.1) Silver(I)-catalyzed the synthesis of 3,4-disubstituted dihydroquinolin- 2(1H)-ones using carboxylic acids as radical source.Using cinnamic acids as starting materials, amide compounds were obtained through the reaction of chlorination and amidation. Then employing carboxylic acids and amide compounds as substrate, thirty-six 3,4-disubstituted dihydroquinolin-2(1H)-ones were synthesized in total by radical addition-cyclization with Ag NO3 as catalyst and K2S2O8 as oxidant. All of them were characterized by 1H NMR, ESI-MS and 13 C NMR, some of them were characterized by X-ray diffraction analysis.2) Silver(I)-catalyzed the synthesis of 3-acyl-4-arylquinolin-2(1H)-ones using ketoacids as radical source.Using cinnamic acids as starting materials, amide compounds were obtained through the reaction of chlorination and amidation. Employing the synthetic amide compounds and ketoacids as starting materials, eight kinds of 3-acyl-4-arylquinolin-2(1H)-ones were synthesized in total by radical addition-cyclization with Ag NO3 as catalyst and K2S2O8 as oxidant. All of them were characterized by 1H NMR, ESI-MS and 13 C NMR.3) n-Bu4NBr/K2S2O8 mediated the synthesis of 3-acyl-4-arylquinolin-2(1H)-ones using aldehydes as radical source.Using cinnamic acids as starting materials, amide compounds were obtained through the reaction of chlorination and amidation. Using the synthetic amide compounds and aldehydes as starting materials, twenty-one kinds of 3-acyl-4- arylquinolin-2(1H)-ones were synthesized in total by radical addition-cyclization with n-Bu4NBr/K2S2O8 as free radical initiator. And all of them were characterized by 1H NMR, ESI-MS and 13 C NMR.