A suspension of (6bR,10aS)-3-methyl-2,3,6b,9,10,10a-hexahydro-1H-pyrido-[3′,4′:4,5]-pyrrolo[1,2,3-de]quinoxaline (ca. 11.8 g, ca. 50 mmol), 4-chloro-4′-fluorobutyrophenone (15.0 g, 74.8 mmol), triethylamine (30 mL, 214 mmol), and potassium iodide (12.6 g, 76 mmol) in dioxane (65 ml) and toluene (65 ml) is heated to reflux for 7 hours. After filtration and evaporation of the solvent, 200 ml of DCM is added. The DCM solution is washed with brine, dried (Na2SO4) and concentrated to approximately 55 ml. The concentrated solution is added dropwise to 600 ml of 0.5N HCl ether solution. The solid is filtered off and washed with ether and then dissolved in water. The resulting aqueous solution is basified with 2N NaOH and extracted with DCM. The DCM layers are combined, washed with brine (2×200 mL) and dried (Na2SO4). Evaporation of the solvent and chromatography of the residue over silica gel gives 4-((6bR,10aS)-3-methyl-2,3,6b,9,10,10a-hexahydro-1H-pyrido-[3′,4′:4,5]-pyrrolo[1,2,3-de]quinoxalin-8-(7H)-yl)-1-(4-fluorophenyl)-1-butanone.
