Dess-Martin periodinane (0.316 g) was added to stirred solution of (2-tert-butylthiazol-4-yl)(9-((4-(2-hydroxyethyl)thiophen-2-yl)methyl)-1-oxa-4,9-diazaspiro[5.5]undecan-4-yl)methanone (example 43, step d) (0.23 g) and TFA (0.05 mL) in DCM (5 mL). After 40 min the reaction mixture was treated with aqueous saturated sodium thiosulphate solution (5 mL), saturated sodium bicarbonate solution (5 mL) and ethyl acetate (30 mL). The mixture was extracted twice with ethyl acetate, the combined organics were washed with saturated sodium bicarbonate solution, acetic acid (0.08 mL) was added, then the solution was dried over sodium sulphate, filtered, and then evaporated in vacuo to afford the subtitled compound. Yield 0.23 g. Used directly.
