1: 66 percent / POCl3, Et3N / CH2Cl2 / 2 h / 0 °C 2: 75 percent / dimethylformamide / 24 h / 25 °C 3: 95 percent / aq. NaOH / methanol / 18 h / Ambient temperature 4: 68 percent / N,N-dimethylacetamide / 3 h / Heating View Scheme

Multi-step reaction with 2 steps 1: 66 percent / POCl3, Et3N / CH2Cl2 / 2 h / 0 °C2: 75 percent / dimethylformamide / 24 h / 25 °C  

Multi-step reaction with 2 steps 1: 66 percent / POCl3, Et3N / CH2Cl2 / 2 h / 0 °C2: 80 percent / dimethylformamide / 6 h / 25 °C