1.1: POCl3; pyridine / acetone / 0.5 h / 18 - 20 °C 1.2: 65 percent / aq. HCl / acetone / 30 h / -5 °C 2.1: 97 percent / NaBH4 / methanol / 1 h / 0 - 20 °C 3.1: 95 percent / NaOH / methanol / 0.17 h / Heating View Scheme

1: With pyridine; trichlorophosphate in acetone T=18 - 20°C; Beckmann rearrangement; 0.5 h; 2: With hydrogenchloride in acetone T=-5°C; 30 h; Further stages.;