in N,N-dimethyl-formamide T=90°C; 1 h;

1: 77.2 percent / HCOOH / 2 h / 110 °C 2: 92.5 percent / NaOH / dimethylformamide / 2 h / 85 - 90 °C 3: 95.5 percent / K2CO3 / CH2Cl2 / 0.5 h / 0 - 5 °C 4: 70.3 percent / dimethylformamide / 1 h / 90 °C View Scheme

1: 92.5 percent / NaOH / dimethylformamide / 2 h / 85 - 90 °C 2: 95.5 percent / K2CO3 / CH2Cl2 / 0.5 h / 0 - 5 °C 3: 70.3 percent / dimethylformamide / 1 h / 90 °C View Scheme

1: 95.5 percent / K2CO3 / CH2Cl2 / 0.5 h / 0 - 5 °C 2: 70.3 percent / dimethylformamide / 1 h / 90 °C View Scheme

1: 77.2 percent / HCOOH / 2 h / 110 °C 2: 92.5 percent / NaOH / dimethylformamide / 2 h / 85 - 90 °C 3: 95.5 percent / K2CO3 / CH2Cl2 / 0.5 h / 0 - 5 °C 4: 70.3 percent / dimethylformamide / 1 h / 90 °C View Scheme