tert-butyl 5'-(4,4,4-trifluoro-3-(nitromethyl)-3-(3,4,5-trichlorophenyl)butanoyl)-3'H-spiro[azetidine-3,1'-isobenzofuran]-1-carboxylate → tert-butyl 5'-(3-(3,4,5-trichlorophenyl)-3-(trifluoromethyl)-3,4-dihydro-2H-pyrrol-5-yl)-3'H-spiro[azetidine-3,1'-isobenzofuran]-1-carboxylate

Participants

Reaction Steps

A solution of tert-butyl 5′-(4,4,4-trifluoro-3-(nitromethyl)-3-(3,4,5-trichlorophenyl)butanoyl)-3′H-spiro[azetidine-3,1′-isobenzofuran]-1-carboxylate (Preparation 3, 5.1 g, 8.97 mmol) in ethanol (51 mL) was purged with nitrogen gas for 30 minutes. To this reaction mixture was added pre-washed Raney Nickel (1.22 g, 50% suspension in water). Reaction mixture was stirred under hydrogen atmosphere using balloon for 16 hours at room temperature. Progress of the reaction was monitored by TLC. After consumption of intermediate-4, reaction mixture was filtered through celite bed, the bed was washed with 10% MeOH in DCM (30 mL). The filtrate was concentrated to get 4 g off white solid as crude mass, crude was purified by column chromatography on silica gel using 230-400 silica mesh. Desired product was eluted in 8% ethyl acetate in n-Hexane to get 1.6 g off white semi-solid as desired product and 1.5 g of starting material was recovered. 1H NMR (400 MHz, CDCl3) δ: 1.47 (s, 9H), 3.43 (d, J=17.52 Hz, 1H), 3.76-3.81 (m, 1H), 4.13 (d, J=9.64 Hz, 2H), 4.32 (d, J=9.56 Hz, 2H), 4.42 (d, J=17.12 Hz 1H), 4.87 (d, J=17.12 Hz, 1H), 5.13 (s, 2H), 7.39 (s, 2H), 7.54 (d, J=7.92 Hz, 1H), 7.73 (s, 1H), 7.83 (d, J=7.92 Hz, 1H).

Provenance & Evidence