Pd2hpp4; oxygen in tetrahydrofuran T=0°C; P=760.051 Torr; 20 h; regioselective reaction;

3-ethyl-5-(2-hydroxyethyl)-4-methyl-1,3-thiazolium bromide; triethylamine in N,N-dimethyl-formamide T=60°C; 24 h;

1.1: O3 / methanol / -78 °C 1.2: 27 percent / DMS / methanol / 24 h / 20 °C 2.1: 47 percent / 3-ethyl-5-(2-hydroxyethyl)-4-methylthiazolium bromide; Et3N / dimethylformamide / 24 h / 60 °C View Scheme