1: [3-(methylamino)propyl](triphenyl)phosphonium bromide hydrobromide With n-butyllithium in tetrahydrofuran; n-heptane 1.5 h; 2: 6,11-dihydro-dibenz[b,e]oxepin-11-one in tetrahydrofuran; n-heptane 10 h; Heating / reflux; 3: With hydrogenchloride in water pH=2;

1: 80 percent / 1.) NaHCO3 / toluene / 6 h / Heating 2: 50 percent / KOH / butan-1-ol / 4 h / Heating View Scheme