cesium fluoride; tetrakis(triphenylphosphine) palladium(0) in 1,4-dioxane Suzuki coupling; Heating;

1,3-bis-(diphenylphosphino)propane; palladium diacetate; triethylamine in 1,4-dioxane T=100°C; P=7500.75 Torr; 16 h; Inert atmosphereAutoclave;

(5aS,10bR)-5a,10b-dihydro-2-(2,4,6-trimethylphenyl)-4H,6H-indeno[2,1-b]-1,2,4-triazolo[4,3-d]-1,4-oxazinium chloride; triethylamine in ethyl acetate T=80°C; 4 h; Inert atmosphereMolecular sieve;

in acetone; acetonitrile 50 h; Ambient temperatureIrradiation;

1: acetic acid anhydride / 135 °C 2: sodium hydroxide / 245 °C View Scheme

potassium fluoride T=80°C; 10.5 h; Inert atmosphere;

1: CHCl3; H2O / 0.83 h 2: 1. POCl3 / 1. 50-55 deg C, 1h; 2. CHCl3, reflux, 8-10h View Scheme

1: SOCl2 2: CHCl3; H2O / 0.83 h 3: 1. POCl3 / 1. 50-55 deg C, 1h; 2. CHCl3, reflux, 8-10h View Scheme

1.1: sodium hydride / dimethyl sulfoxide / 1 h / 0 °C / |Inert atmosphere 1.2: 3 h / 20 °C / |Inert atmosphere 2.1: hydrogenchloride / water; chloroform / 3 h / 20 °C / |Inert atmosphere 3.1: Dess-Martin periodane / dichloromethane / 1 h / 20 °C / |Inert atmosphere 4.1: triethylamine; (5aS,10bR)-5a,10b-dihydro-2-(2,4,6-trimethylphenyl)-4H,6H-indeno[2,1-b]-1,2,4-triazolo[4,3-d]-1,4-oxazinium chloride / ethyl acetate / 4 h / 80 °C / |Inert atmosphere; |Molecular sieve View Scheme

1: Dess-Martin periodane / dichloromethane / 1 h / 20 °C / |Inert atmosphere 2: triethylamine; (5aS,10bR)-5a,10b-dihydro-2-(2,4,6-trimethylphenyl)-4H,6H-indeno[2,1-b]-1,2,4-triazolo[4,3-d]-1,4-oxazinium chloride / ethyl acetate / 4 h / 80 °C / |Inert atmosphere; |Molecular sieve View Scheme