Hydrochloric Acid → 6-{(E)-2-[2-(Cyclopropylmethoxy)-3-methoxyphenyl]vinyl}imidazo[2,1-b][1,3]thiazole-5-carboxylic acid

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Reaction Steps

To a stirred solution of Step 4 intermediate (495 mg, 1.242 mmol) in THF (10 ml) was added LiOH.H2O (105 mg, 2.484 mmol) dissolved in water (10 ml). The mixture was stirred for 2 h at room temperature. Solvent was evaporated under reduced pressure and the residue obtained was acidified with 1 N HCl to pH 4 and extracted with ethyl acetate (2×100 mL). The combined ethyl acetate extracts were washed with water (2×25 mL) and dried (Na2SO4). Evaporation of solvent under reduced pressure afforded 0.381 g of the product as a white solid; 1H NMR (300 MHz, DMSO-d6) δ 0.26-0.28 (m, 2H), 0.49-0.53 (m, 2H), 1.16-1.22 (m, 1H), 3.75 (d, J=7.5 Hz, 2H), 3.79 (s, 3H), 6.95-6.99 (m, 1H), 7.04 (t, J=7.8 Hz, 1H), 7.16-7.27 (m, 1H), 7.39 (d, J=3.9 Hz, 1H), 7.71 (d, J=15.9 Hz, 1H), 7.79 (d, J=15.9 Hz, 1H), 8.10 (d, J=3.9 Hz, 1H), 13.44 (br s, 1H); ESI-MS (m/z) 369.08 (M−H)−.

Provenance & Evidence