1: 5-(4-chloro-[1,2,5]thiadiazol-3-yl)pyrimidine With sodium hydrogensulfide in N,N-dimethyl-formamide T=100°C; 24 h; 2: propargyl halide With potassium carbonate in N,N-dimethyl-formamide T=20°C;

1.1: H2O / 5 - 10 °C 1.2: 67 percent / acetic acid / H2O / 2 h / 20 °C 2.1: 39 percent / NH4Cl; NH4OH / acetonitrile / 3 h / Heating 3.1: 73 percent / S2Cl2 / dimethylformamide / 2 h / 80 °C 4.1: sodium hydrosulfide hydrate / dimethylformamide / 24 h / 100 °C 4.2: 73 percent / K2CO3 / dimethylformamide / 20 °C View Scheme

1.1: 39 percent / NH4Cl; NH4OH / acetonitrile / 3 h / Heating 2.1: 73 percent / S2Cl2 / dimethylformamide / 2 h / 80 °C 3.1: sodium hydrosulfide hydrate / dimethylformamide / 24 h / 100 °C 3.2: 73 percent / K2CO3 / dimethylformamide / 20 °C View Scheme

1.1: 73 percent / S2Cl2 / dimethylformamide / 2 h / 80 °C 2.1: sodium hydrosulfide hydrate / dimethylformamide / 24 h / 100 °C 2.2: 73 percent / K2CO3 / dimethylformamide / 20 °C View Scheme