1: 5-bromo-thiophene-2-carboxylic acid ethyl ester With chloro-trimethyl-silane; aluminium; lithium chloride; PbCl2 in tetrahydrofuran T=25 - 50°C; Inert atmosphere; 2: With zinc diacetate in tetrahydrofuran T=25°C; 0.333333 h; Inert atmosphere; 3: 4-bromo-benzaldehyde With Pd-PEPPSI-IPr in tetrahydrofuran T=25 - 30°C; Inert atmosphere; chemoselective reaction;