1: 3-bromo-2-methyl-5-methyl-thiophene With n-butyllithium in tetrahydrofuran; hexane T=-78°C; 0.25 h; Inert atmosphere; 2: tributoxyborane in tetrahydrofuran; hexane T=-78 - 20°C; Inert atmosphere;

1: With n-butyllithium in tetrahydrofuran 2: With tributoxyborane 3: With hydrogenchloride

n-butyllithium in tetrahydrofuran; hexane soln. of n-BuLi in hexane added at -78°C under Ar to soln. of C4HSMe2I on THF; react. mixt. stirred at this temp. for 30 min and Bu3B then added with additional stirring for 1 h; mixt. slow heated, cooled to 0°C ...; NaOH added ...; ppt. filtered off, washed with small amt. and dried in desiccator; elem.anal.;

1: bromine 2: n-butyllithium / water 3: n-butyllithium View Scheme

1: n-butyllithium / water 2: n-butyllithium View Scheme

tetrakis(triphenylphosphine) palladium(0); sodium carbonate in tetrahydrofuran Suzuki cross-coupling reaction; Heating;