1: carbonic acid diethyl ester With potassium tert-butylate in toluene T=60 - 65°C; 0.5 h; 2: 1-thiophen-3-yl-ethanone in toluene T=75 - 80°C; 1.5 h;

1: With sodium hydride in toluene 0.5 h; Heating / reflux; 2: With acetic acid in toluene T=0°C;