Cesium carbonate → tert-butyl 5'-(3-(3,5-dichlorophenyl)-4,4,4-trifluorobut-2-enoyl)-3'H-spiro[azetidine-3,1'-isobenzofuran]-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

In 100 mL two neck RBF equipped with dean-stark apparatus, the stirred solution of tert-butyl 5′-acetyl-3′H-spiro[azetidine-3,1′-isobenzofuran]-1-carboxylate (Preparation 1, 6.65 g, 21.95 mmol) in toluene (20 mL) and trifluorotoluene (20 mL) was added 1-(3,5-dichloro-phenyl)-2,2,2-trifluoro-ethanone (6.133 g, 25.24 mmol) and Cs2CO3 (0.71 g, 2.20 mmol) at room temperature. Resulting reaction mixture was stirred at 110° C. for 16 hours. After complete consumption of starting material, the reaction mixture was diluted with tert-butylmethyl ether (60 mL) and filtered through celite bed. Filtrate was concentrated to get as brown sticky oil (7.2 g, crude). Crude compound was purified by column chromatography using silica gel (230-400 mesh). Desired compound was eluted in 20% ethyl acetate in n-hexane to give light yellow solid (5.1 g, 43.97%). LC-MS (m/z): 525.9 (M−H).

Provenance & Evidence