(E)-3-[3'-(4"-Fluorophenyl)-1'-(1"-methylethyl)-1H-indol-2"-yl]-2-propnal

34900-01-1

93957-49-4

93957-50-7

The general procedure for the synthesis of (E)-3-(3-(4-fluorophenyl)-1-isopropyl-1H-indol-2-yl)acrolein from the compound (CAS:34900-01-1) and 1-isopropyl-3-(4-fluorophenyl)indole is as follows: 1. A suspension of 3-(4-fluorophenyl)-1-(1-methylethyl)-1H-indole (35.8 g) with phosphorus trichloride (31.4 g) in acetonitrile (35 ml) was cooled to 5 °C to prepare a crude acrolein solution. A 32.3 g solution of Example 3a in acetonitrile (40 ml) was added dropwise over 30 minutes. 2. the reaction mixture was gradually warmed to 60 °C and stirred at this temperature for 4 hours. 3. water (300 ml) was added and stirring was continued at 60 °C for 1 h. The solid formed was filtered through a Buchner funnel and washed with 75 ml of water. 4. The wet solid (49.7 g) was dissolved in toluene (250 ml), diatomaceous earth (1 g) and charcoal (0.5 g) were added and stirred for 30 minutes at room temperature. 5. After filtration of the solid, the solvent was removed by distillation under reduced pressure and the residue was dissolved in isopropanol (72 ml) at 75 °C. 6. The solution was cooled to 20 °C and stirred for 1 h at room temperature. 7. The precipitate was filtered through a Buchner funnel, washed twice with isopropanol (15 ml) and dried under vacuum at 60 °C. Finally 30.2 g (70% molar yield) of the target product was obtained. Example 4b 3-[3-(4-fluorophenyl)-1-(1-methylethyl)-1H-indol-2-yl]-2-propenal was synthesized as follows: 1. A solution was prepared by cooling a suspension of 3-[3-(4-fluorophenyl)-1-(1-methylethyl)-1H-indole (130.7 g) with phosphorus trichloride (114.6 g) in acetonitrile (128 ml) to 5 °C. 2. a solution of crude acrolein (116.9 g from Example 4a) in acetonitrile (145 ml) was added dropwise over 60 min. 3. the reaction mixture was gradually warmed to 60 °C and stirred at this temperature for 6 hours. 4. After addition of water (1100 ml) and continued stirring at 60 °C for 1 h, the solid formed was filtered through a Buchner funnel and washed with water (250 ml x 3). 5. The wet solid (131 g) was dissolved in toluene (1050 ml), diatomaceous earth (2.7 g) and charcoal (4 g) were added and stirred at room temperature for 30 min. 6. After filtration of the solid, the mixture was washed with water (500 ml x 2), the phases were separated and the organic solvent was removed by distillation under reduced pressure. 7. The residue was dissolved with isopropanol (260 ml) at 75 °C, the solution was cooled to 10 °C and stirred for 1 hour. 8. The precipitate was filtered through a Buchner funnel, washed with isopropanol (60 ml x 3) and dried under vacuum at 60 °C. A final 84.2 g (53% molar yield) of the target product was obtained.