Synthesis of Thieno[3,4-b]quinoxaline and Derivatives
摘要:
The highly reactive o-quinonoid heterocycles thieno[3,4-b]quinoxaline (1a) and its 6,7-dimethyl derivative (1b) have been synthesized by a base-catalyzed Pummerer reaction and isolated in crystalline form. In contrast, the 1,3-dibromothieno[3,4-b]quinoxaline (8) could be characterized in solution but not isolated in pure farm. The readily prepared 1,3-dihydrothieno[3,4-b]quinoxaline (5a) underwent a direct Knoevenagel condensation with thiophene-2-carboxaldehyde to give the stilbenoid 14a. Sulfide 5a was also converted in a two-step process to the stable 1,3-diformylthieno[3,4-b]quinoxaline 11a.
Synthesis of Thieno[3,4-b]quinoxaline and Derivatives
摘要:
The highly reactive o-quinonoid heterocycles thieno[3,4-b]quinoxaline (1a) and its 6,7-dimethyl derivative (1b) have been synthesized by a base-catalyzed Pummerer reaction and isolated in crystalline form. In contrast, the 1,3-dibromothieno[3,4-b]quinoxaline (8) could be characterized in solution but not isolated in pure farm. The readily prepared 1,3-dihydrothieno[3,4-b]quinoxaline (5a) underwent a direct Knoevenagel condensation with thiophene-2-carboxaldehyde to give the stilbenoid 14a. Sulfide 5a was also converted in a two-step process to the stable 1,3-diformylthieno[3,4-b]quinoxaline 11a.
Synthesis of Thieno[3,4-b]quinoxaline and Derivatives
作者:Joerg Pohmer、M. V. Lakshmikantham、Michael P. Cava
DOI:10.1021/jo00130a032
日期:1995.12
The highly reactive o-quinonoid heterocycles thieno[3,4-b]quinoxaline (1a) and its 6,7-dimethyl derivative (1b) have been synthesized by a base-catalyzed Pummerer reaction and isolated in crystalline form. In contrast, the 1,3-dibromothieno[3,4-b]quinoxaline (8) could be characterized in solution but not isolated in pure farm. The readily prepared 1,3-dihydrothieno[3,4-b]quinoxaline (5a) underwent a direct Knoevenagel condensation with thiophene-2-carboxaldehyde to give the stilbenoid 14a. Sulfide 5a was also converted in a two-step process to the stable 1,3-diformylthieno[3,4-b]quinoxaline 11a.