N-bromosuccinmide; water in dimethyl sulfoxide T=0 - 20°C; 4.5 h;

1.1: ammonia / methanol / 7 h / 0 - 20 °C 2.1: sodium hydride / mineral oil; N,N-dimethyl-formamide / 1.25 h / 0 °C 2.2: 5 h / 80 °C 3.1: N-bromosuccinmide; water / dimethyl sulfoxide / 2 h / 0 - 20 °C View Scheme

1.1: sodium hydride / mineral oil; N,N-dimethyl-formamide / 1.25 h / 0 °C 1.2: 5 h / 80 °C 2.1: N-bromosuccinmide; water / dimethyl sulfoxide / 2 h / 0 - 20 °C View Scheme

sodium hydroxide in tetrahydrofuran T=20°C; 2 h;