SYNTHESIS OF 6-R-5-ARYL-1,3-DIOXO-1,2,3,4-TETRAHYDRO[1]BENZOTHIENO[3',2':4,5]PYRIDO[2,3-<i>d</i>]PYRIMIDIN-5-IUM SALTS AND 6-R-5-ARYL-5,6-DIHYDRO[1]BENZOTHIENO[3',2':4,5]PYRIDO[2,3-<i>d</i>]PYRIMIDINE-1,3(2<i>H</i>,4<i>H</i>)-DIONES
DOI:
https://doi.org/10.1007/383Keywords:
benzothiophen-3(2H)-one, 5-(benzothiophen-3-yl)pyrimidine-2, 4, 6(1H, 3H, 5H)-trione, pyrilium salts, pyrimidine-2, 6-R-5-aryl-1, 3-dioxo-1, 2, 3, 4-tetrahydro[1]benzothieno[3', 2', 5]pyrido[2, 3-d]pyrimidin-5-ium chlorides, acylation, reductionAbstract
Acylation of 5-(benzothiophen-3-yl)pyrimidine-2,4,6(1H,3H,5H)-trione using acetic and propionic anhydride in the presence of 70% perchloric acid gave the 6-methyl(ethyl)-1,3-dioxo-1,2,3,4-tetra-hydro[1]benzothieno[3',2':4,5]pyrano[2,3-d]pyrimidin-5-ium perchlorates. Hydrolysis of the pyrano[2,3-d]pyrimidin-5-ium salts in aqueous alcohol solution gave 5-(2-acylbenzothiophen-3-yl)-pyrimidine-2,4,6(1H,3H,5H)-triones. Cyclocondensation of the latter with aromatic amine hydrochlorides produced 6-R-5-aryl-1,3-dioxo-1,2,3,4-tetrahydro[1]benzothieno[3',2':4,5]pyrido[2,3-d]-pyrimidin-5-ium chlorides. 6-R-5-Aryl-5,6-dihydro[1]benzothieno[3',2':4,5]pyrido[2,3-d]pyrimidine-1,3(2H,4H)-diones were synthesized by reduction of the pyrimidinium chlorides using sodium borohydride.
Authors: V. S. Tolkunov, A. B. Eresko, A. V. Mazepa, and S. V. Tolkunov.
English Translation in Chemistry of Heterocyclic Compounds, 2013, 49 (6), pp 941-948