Acetic Acid → (9-(4-(2-(tert-Butyldimethylsilyloxy)ethyl)phenethyl)-1-oxa-4,9-diazaspiro[5.5]undecan-4-yl)(2-methylthiazol-4-yl)methanone

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Reaction Steps

(2-Methylthiazol-4-yl)(1-oxa-4,9-diazaspiro[5.5]undecan-4-yl)methanone trifluoroacetate (example 4, step h) (0.26 g) was added to a solution of 2-(4-(2-(tert-butyldimethylsilyloxy)ethyl)phenyl)acetaldehyde (example 5, step c) (0.2 g) and acetic acid (0.04 mL) in NMP (5 mL). The resulting mixture was stirred for 5 min then sodium triacetoxyborohydride (0.23 g) was added. The mixture was stirred for 1 h, poured into pH 7.2 buffer (50 mL) and extracted with ethyl acetate (3×50 mL). The combined organic solutions were washed with pH 7.2 buffer (50 mL) and brine (50 mL), then dried over sodium sulphate, filtered and evaporated in vacuo. Purification was by silica gel chromatography eluting with 80:15:5 isohexane:ethyl acetate:triethylamine to 95:5 ethyl acetate:triethylamine to give the subtitled compound as a yellow oil. Yield 0.30 g.

Provenance & Evidence