Water → 2-(4-Bromo-2-methyl-phenyl)-8-oxa-2-aza-spiro[4.5]decan-1-one

Participants

Reaction Steps

To a clear solution of 4-[2-(4-Bromo-2-methyl-phenylamino)-ethyl]-tetrahydro-pyran-4-carboxylic acid methyl ester (2 g, 5.6 mmol) in THF (80 mL) was added a solution of potassium t-butoxide (1M in THF) 2.5 mL (2.5 mmol, 0.45 equiv.) at r.t. (water bath at rt). The clear solution turned a little bit cloudy. After 30 min, TLC (5% MeOH in DCM) showed the reaction is complete (spot to spot), LC/MS detected the product peak of 324/326 (t 3.267 min). The reaction was cooled tin an ice-water bath, diluted with 100 mL of DCM, quenched with 20 mL of water. The two layers were separated. The aqueous layer was extracted with DCM (2×20 mL). The combined DCM extracts were washed with brine, and concentrated on rotavap to yield 1.79 g (98% yield) of the title product as a white solid.

Provenance & Evidence