toluene-4-sulfonic acid in benzene 72 h; Reflux;

toluene-4-sulfonic acid in benzene acetalation; 24 h; Heating;

toluene-4-sulfonic acid in hexane; dichloromethane

toluene-4-sulfonic acid in dichloromethane T=20°C; 0.0833333 h; chemoselective reaction;

1: 49 percent / BINAP; t-BuOK / Pd2(dba)3 / toluene / 5 h / 80 °C 2: 73 percent / aq. H2SO4; trifluoroacetic acid / 2 h / 20 °C View Scheme

1: 4-bromobenzaldehyde 2,2-dimethylpropane-1,3-diol acetal With iodine; magnesium in tetrahydrofuran T=30 - 35°C; 2 h; 2: 2-bromo-pyridine With tetrakis(triphenylphosphine) palladium(0) in tetrahydrofuran; toluene T=50°C; 2.5 h; 3: With water Acidic aqueous solution; Conversion of starting material;

1: 4-bromobenzaldehyde 2,2-dimethylpropane-1,3-diol acetal With magnesium in tetrahydrofuran 2 h; Heating; 2: carbon disulfide in tetrahydrofuran T=-5 - 20°C;