potassium carbonate in N,N-dimethyl-formamide; butanone 1.5 h; Heating;

potassium carbonate in acetone

potassium tert-butylate; oxygen; triethyl phosphite in N,N-dimethyl-formamide T=-15 - -10°C;

1: 88 percent / HBr, Br2 / CHCl3; acetic acid / 1.) RT, 5 h, 2.) 100-110 deg C, 20 h 2: 100 percent / LiCO3 / dimethylformamide / 1.) RT, 24 h, 2.) 60-70 deg C View Scheme