p-Toluenesulfonic acid → (5R)-5-{4-[2-(5-ethylpyridin-2-yl)ethoxy]benzyl}-1,3-thiazolidine-2,4-dione tosylate

Participants

Reaction Steps

To a solution of p-toluenesulphonic acid (0.8 g) in IPA (12 mL) at 40° C. was added (5R)-5-{4-[2-(5-ethylpyridin-2-yl)ethoxy]benzyl}-1,3-thiazolidine-2,4-dione(−)-O,O′-dibenzoyl-L-tartrate (2.0 g, d.e. >99%) to give a suspension which was allowed to cool to ambient temperature. After 30 min, the solid was collected by filtration, washed with 5 ml of IPA at 0° C. and dried under vacuum to give the title compound (1.32 g). (Method 14) 99.41%, Rt 15.49 min.; 0.59%, Rt 17.52 min.; e.e. 98.82%. (Method 2) Rt 2.88 min, m/z 357 [M-C7H8SO3+]. 1H NMR (400 MHz, DMSO-d6): δ 1.23 (3H, t, J 8.2), 2.28 (3H, s), 2.76 (2H, q, J 7.4), 3.05 (1H, dd, J 8.8, 14.0), 3.28 (1H, dd, J 4.1, 14), 3.38 (2H, t, J 5.9), 4.35 (2H, t, J 5.9), 4.86 (1H, dd, J 4.4, 9.1), 6.86 (2H, d, J 8.8), 7.12 (4H, dd, J 8.6, 16.6), 7.47 (2H, d, J 8.8), 7.90 (1H, d, J 8.3), 8.30 (1H, d, J 8), 8.68-8.71 (1H, m).

Provenance & Evidence