1,4-Dioxane → (R)-N-(1-(1H-indol-3-yl)propan-2-yl)-2-fluoro-2-methylpropan-1-amine

Participants

Reaction Conditions

Reaction Steps

(2R)-1-(1H-indol-3-yl)propan-2-amine (3.81 kg, 21.21 moles) was added to a 100 L glass lined jacketed vessel under an atmosphere of nitrogen. 1,4-dioxane (23 L) was added, and the agitator was switched on. Diisopropylethylamine (5.55 L 31.82 moles) was added to the stirred suspension followed by (2-fluoro-2-methyl-propyl)trifluoromethanesulfonate (5.55 kg, 23.77 moles). 1,4-Dioxane (4 L) was added to the vessel, and the mixture was heated to 75° C. Heating was continued for 24 hours before cooling the mixture to 25°C. Water (30.5 L) was added to the vessel, followed by toluene (30.5 L). After 40 minutes the agitator was switched off and the layers were allowed to separate. The aqueous layer was removed and water (30.5 L) was added to the organic solution. The mixture was agitated for 15 minutes before allowing the layers to separate. The aqueous layer was removed from the vessel. The organic solution was concentrated by vacuum distillation (jacket temperature 65° C., 110 mbar pressure) until approximately 27 L of distillate had been removed. The remaining solution in the vessel was cooled to afford (R)—N-(1-(1H-indol-3-yl)propan-2-yl)-2-fluoro-2-methylpropan-1-amine as a solution in toluene (33% w/w) (15.4 Kg, 97%). 1H NMR (500 MHz, DMSO, 27° C.) 0.98 (3H, d), 1.26 (3H, d), 1.30 (3H, d), 2.57-2.75 (3H, m, 2.81 (1H, dd), 2.84-2.92 (1H, m), 6.97 (1H, t), 7.06 (1H, t), 7.11-7.22 (1H, multiplet obscured by toluene signals), 7.34 (1H, d), 7.52 (1H, d), 10.80 (1H, s).

Provenance & Evidence