Dess-Martin periodinane (0.16 g) was added to a stirred solution of (9-(3-(2-hydroxyethyl)benzyl)-1-oxa-4,9-diazaspiro[5.5]undecan-4-yl)(5-methylthiophen-2-yl)methanone (0.13 g) (example 9, step c) and trifluoroacetic acid (0.036 g) in DCM (4 mL) under nitrogen. After 0.5 h, saturated sodium thiosulphate solution (5 mL) and saturated sodium bicarbonate solution (5 mL) were added and the reaction mixture extracted twice with ethyl acetate. The combined organic extracts were washed with saturated sodium bicarbonate and brine, dried over sodium sulphate, filtered and evaporated in vacuo to give the subtitled compound. Yield 0.13 g. Used directly.
