1: With thiourea in ethanol; acetic acid 8 h; Heating / reflux; 2: With sodium hydroxide in water; toluene T=45 - 55°C; 0.25 h; 3: With hydrogenchloride; water Product distribution / selectivity; more than 3 stages;

in isopropyl alcohol T=85°C; 16 h; Heating / reflux;

1: With thiourea in ethanol; acetic acid 6 h; Heating / reflux; 2: With sodium hydroxide in ethanol; water; acetic acid; toluene T=60°C;

in isopropyl alcohol T=85°C; 16 h; Heating / reflux;