Nitromethane → tert-butyl 5'-(4,4,4-trifluoro-3-(nitromethyl)-3-(3,4,5-trichlorophenyl)butanoyl)-3'H-spiro[azetidine-3,1'-isobenzofuran]-1-carboxylate

Participants

Reaction Steps

To the stirred solution of tert-butyl 5′-(4,4,4-trifluoro-3-(3,4,5-trichlorophenyl)but-2-enoyl)-3′H-spiro[azetidine-3,1′-isobenzofuran]-1-carboxylate (Preparation 2, 8.6 g, 15.33mmol) in DMF (215 mL) was added nitro methane (8.20 mL, 153.29mmol) and DBU (2.22 mL, 14.87 mmol) at room temperature. Reaction mixture was stirred at room temperature for 16 hours. After complete consumption of starting material, the reaction mixture was quenched with addition of water (250 mL) and extracted with ethyl acetate (2×300 mL). Combined organic layer was washed with LiCl Solution (2×400 mL) and brine (500 mL). Organic layer was dried over sodium sulfate and concentrated to get crude compound sticky solid (11.23 g). Purification was done by column chromatography using silica gel (230-400 mesh). Desired compound was eluted in 10% ethyl acetate in n-hexane to afford light yellow sticky liquid (5.10 g, impure-used as such in next step). 1H NMR (400 MHz, CDCl3) δ: 1.48 (s, 9H), 3.95 (d, J=18.72 Hz, 1H), 4.13-4.18 (m, 3H), 4.33-4.36 (m, 2H), 5.17-5.18 (m, 2H), 5.42 (d, J=12.2 Hz, 1H), 5.58 (d, J=12.16 Hz, 1H), 7.20 (s, 1H), 7.31 (s, 1H), 7.60-7.65 (m 1H), 7.78 (d, J=16.92 Hz, 1H), 7.98-8.00 (m, 1H). LC-MS (m/z): 622.9 (M−H).

Provenance & Evidence