tert-butyl 5'-(3-(3,5-dichloro-4-fluorophenyl)-4,4,4-trifluorobut-2-enoyl)-3'H-spiro[azetidine-3,1'-isobenzofuran]-1-carboxylate → tert-butyl 5'-[3-(3,5-dichloro-4-fluorophenyl)-3-thioacetyl-4,4,4-trifluorobutanoyl]-3'H-spiro[azetidine-3,1'-isobenzofuran]-1-carboxylate

Participants

Reaction Steps

The starting material, tert-butyl 5′-[3-(3,5-dichloro-4-fluorophenyl)-4,4,4-trifluorobut-2-enoyl]-3′H-spiro[azetidine-3,1′-isobenzofuran]-1-carboxylate (3.0 g, 6.0 mmoL), was dissolved in dichloromethane (14 mL) and to this solution were added thioacetic acid (2.6 mL, 6.0 eq) and 2 drops of triethylamine and the resulting mixture was stirred at room temperature for 96 h under argon. Solvents were removed under reduced pressure and the crude product was purified via flash silica gel chromatography to yield 1.3 g of tert-butyl 5′-[3-(3,5-dichloro-4-fluorophenyl)-3-thioacetyl-4,4,4-trifluorobutanoyl]-3′H-spiro[azetidine-3,1′-isobenzofuran]-1-carboxylate. HNMR (400 MHz, CDCl3) δ ppm 8.01 (d, 1H, J=8.0 Hz), 7.82 (s, 1H), 7.60 (d, 1H, J=8.0 Hz), 7.45 (d, 1H, J=5.8 Hz), 5.23 (d, 1H, J=18.5 Hz), 5.17 (s, 2H), 4.35 (d, 2H, J=9.7 Hz), 4.15 (d, 2H, J=9.7 Hz), 3.97 (d, 1H, J=18.5 Hz), 2.33 (s, 3H), 1.50 (s, 9H).

Provenance & Evidence