Isopropanol → HCID 25164128, compound

Participants

Reaction Conditions

Reaction Steps

To a solution of 4-{4-[(6-butyl-8-quinolinyl)oxy]-1-piperidinyl}butyl)amine (for example, as prepared for Intermediate 37 in stages 4a and 4b) (2.57 kg, 1.0 eqv) was added dichloromethane (30.84 L, 12 vol), and triethylamine (2.05 kg, 2.8 eqv) under a nitrogen atmosphere. The reaction mixture was cooled to 0-5° C. and a solution of ethanesulphonyl chloride (commercially available, for example, from Aldrich) (1.86 kg, 2.0 eqv) in dichloromethane (7.71 L, 3 vol) was added dropwise at 0-10° C. After stirring for 2-3 hr at 0-10° C. under nitrogen, the reaction temperature was adjusted to 25-35° C. and stirred for 2-3 hr. A sample was analysed by HPLC to monitor reaction progress. The reaction mixture was quenched at 25-35° C. with water (25.7 L, 10 vol). The organic layer was separated and the aqueous layer extracted with dichloromethane (7.71 L, 3 vol). The combined organics were washed with citric acid solution (5.14 kg, 2 wt dissolved in 25.7 L water, 10 vol). The aqueous layer containing product was collected and the organic layer was again washed with aqueous citric acid solution (0.77 kg, 0.3 wt, dissolved in 3.34 L water, 1.3 vol) and the organic layer was separated. The combined aqueous layers were washed with dichloromethane (12.8 L, 5 vol). Dilute ammonia solution (12.85 L ammonia (22.38%) dissolved in 12.85 L water) was then added to the aqueous layer keeping the temperature at 30-35° C., until the pH reached was between 10-12. The product from the aqueous layer was then extracted with dichloromethane (25.7 L, 10 vol, then 7.71, 3 vol) and the combined organics were again washed with dilute ammonia solution (5.14 L ammonia (22.38%) dissolved in 5.14 L water). The organic layer was finally washed twice with water (25.7 L, 10 vol) then 50-80% solvent was removed by distillation under atmospheric pressure, keeping the temperature below 55° C. The reaction mixture was then concentrated in vacuo (vacuum no less than 600 mm Hg) keeping the temperature below 50° C. To this crude mixture, iso-propylalcohol (7.71 L, 3 vol) was added and concentrated in vacuo (vacuum no less than 600 mm Hg) keeping the temperature below 50° C. To this, methanol (17.99 L, 7 vol) and activated carbon (0.13 kg, 0.05 wt) were added sequentially, and stirred for 15-30 min. The charcoal was filtered over a celite bed (prepared using 1.5 kg celite and 7.71 L methanol), then washed with methanol (7.71 L, 3 vol) and to the combined filtrate, HCl in iso-propylalcohol (22.8%, 3.6 L, 2.65 eqv) was added at 20-30° C., and stirred for 15-30 min. The reaction mass was then concentrated in vacuo (vacuum no less than 650 mm Hg) until a syrup remained which started to solidify, then methanol (12.85 L, 5 vol) was added to the residue to obtain a clear solution. The reaction mass was then stirred at 30-35° C., and ethyl acetate (51.4 L, 20 vol) was added. The reaction mass was then stirred for 1-2 hr at 25-35° C. and then cooled to 5-10° C. for 1-2 hr, then centrifuged. The solid was then washed with methanol:ethyl acetate mixture (1:7, 2.57 L methanol in 17.99 L ethyl acetate) at 5-10° C. and centrifuged. The product was dried in vacuo (vacuum no less than 650 mm Hg) at 50-55° C. for 8-12 hrs. The title compound was obtained in 53.15% yield (2 kg).

Provenance & Evidence