Multi-step reaction with 9 steps
1.1: potassium hydroxide / methanol / 12 h / 20 °C
2.1: boron trifluoride diethyl etherate / tetrahydrofuran / 0.5 h / -60 °C
2.2: -60 - 45 °C / Inert atmosphere
3.1: ChiralPak IA / carbon dioxide; methanol / Resolution of racemate
4.1: boron tribromide / dichloromethane / 18.16 h / -78 - 20 °C
4.2: 0.5 h / 0 - 20 °C
5.1: sodium hydride / tetrahydrofuran / 0 - 20 °C
6.1: piperidine / dichloromethane / 32 °C
7.1: potassium carbonate / N,N-dimethyl-formamide / 4 h / 70 °C
8.1: potassium carbonate / tetrakis(triphenylphosphine) palladium(0) / 1,4-dioxane; water / 2 h / 95 °C
9.1: hydrogenchloride; water / 1,4-dioxane / 20 °C
With
piperidine; hydrogenchloride; boron trifluoride diethyl etherate; water; boron tribromide; sodium hydride; potassium carbonate; potassium hydroxide;
tetrakis(triphenylphosphine) palladium(0);
In
tetrahydrofuran; 1,4-dioxane; methanol; dichloromethane; carbon dioxide; water; N,N-dimethyl-formamide;