Preparation of a 3-thienylmalonic acid or a diester thereof comprising reacting in a polar solvent in the presence of a copper (I) halide a thiophene compound of formula:
wherein X = I or Br
R1 = H or a C1-4 alkyl group
R2 = H or a C1-2 alkyl group
R3 = H or a C1-2 alkyl group
with the proviso that R2 and R3 cannot be an alkyl group simultaneously, with a mono-deprotonated methylene compound of formula:
wherein Z' = Z" is CN or COOR in which R is a C1-4 alkyl group, or Z' = CN and Z" = COOR' in which R' is a C1-2 alkyl group followed by hydrolysis by methods known per se to get the corresponding free acid.
制备
3-噻吩丙二酸或其二酯,包括在极性溶剂中,在卤化
铜(I)的存在下,使 式中的
噻吩化合物发生反应:
式中 X = I 或 Br
R1 = H 或 C1-4 烷基
R2 = H 或 C1-2 烷基
R3 = H 或 C1-2 烷基
在 R2 和 R3 不能同时为烷基的条件下,与式中的
单质子化亚甲基化合物反应:
其中 Z' = Z" 是 CN 或 COOR(其中 R 是 C1-4 烷基),或 Z' = CN 和 Z" = COOR'(其中 R' 是 C1-2 烷基),然后用本身已知的方法进行
水解,得到相应的
游离酸。