Trifluoroacetic acid → 3-(2-Fluoro-3-((4-(2-isopropylthiazole-4-carbonyl)-1-oxa-4,9-diazaspiro[5.5]undecan-9-yl)methyl)phenethoxy)propanoic acid

Participants

Reaction Steps

TFA (10 mL) was cautiously added to a solution of tert-butyl 3-(2-fluoro-3-((4-(2-isopropylthiazole-4-carbonyl)-1-oxa-4,9-diazaspiro[5.5]undecan-9-yl)methyl)phenethoxy)propanoate [Example 7, step c] (3.95 g) in DCM (40 mL). The resulting mixture was stirred for 2 h. The solvent was evaporated and the residue azeotroped twice with acetonitrile. The residue was dissolved in freshly distilled 2-methyltetrahydrofuran (100 mL) and washed 3 times with a mixture of brine and saturated sodium bicarbonate solution (10:1, 100 mL). The organic phase was dried over sodium sulphate, filtered and evaporated. The residue was azeotroped 3 times with isohexane to give the subtitled compound as a white foam. Yield 2.92 g.

Provenance & Evidence