REGIO-SELECTIVE ULLMANN SYNTHESIS OF 4-BROMO-3-METHYL-5-PROPOXY-THIOPHENE-2-CARBOXYLIC ACID
摘要
This invention is directed to a two step regio-selective Ullmann synthesis of 4-bromo-3- methyl-5-propoxy-thiophene-2-carboxylic acid compound of formula 16 comprising the steps of brominating 3-methyl-thiophene-2-carboxylic acid to yield 4,5-dibromo-3-methyl- thiophene-2-carboxylic acid in appropriate bromination organic solvent, and then effecting the selective Ullmann coupling of the 4,5-dibromo-3-methyl-thiophene-2-carboxylic cid with alkali metal propoxide salt using copper catalyst in propanol to yield the compound of formula 16.
申请公布号
WO2008109786(A3)
申请公布日期
2008.12.11
申请号
WO2008US56112
申请日期
2008.03.07
申请人
SANOFI-AVENTIS;AYERS, TIMOTHY A.;GELORMINI, ANN MARIE;SHAY, JOHN J., JR.;SLEDESKI, ADAM W.;YU, YONG
发明人
AYERS, TIMOTHY A.;GELORMINI, ANN MARIE;SHAY, JOHN J., JR.;SLEDESKI, ADAM W.;YU, YONG