1: 3-chlorobenzaldehyde p-toluenesulfonylhydrazone With sodium ethanolate in toluene T=20°C; 0.25 h; 2: phenylacetylene in toluene T=90°C; 12 h; regioselective reaction;

1.1: toluene / 1.58 h / 20 - 50 °C 2.1: sodium ethanolate / toluene / 0.25 h / 20 °C 2.2: 12 h / 90 °C View Scheme