Formic Acid → 5,7-di-tert-butyl-3-(4-trifluoromethyl-phenyl)-3H-benzofuran-2-one

Participants

Reaction Conditions

Reaction Steps

A solution of 12.53 g (28.0 mmol) of compound (201), prepared according to Example 1a, in 150 ml of dry toluene is degassed using argon and then 33.6 mg (0.057 mmol) of dichloro-[1,3bis(diphenylphosphino)propane]palladium(II) and 4.22 ml (112 mmol) of formic acid are added. The autoclave is flushed with carbon monoxide and sealed, and a carbon monoxide pressure of 6 bar is then applied. The reaction mixture is maintained at 140° C. for 14 hours. After cooling to room temperature, the reaction mixture is poured into water and extracted three times using ethyl acetate. The organic phases are combined, dried over sodium sulfate and concentrated using a vacuum rotary evaporator. Filtration of the residue on silica gel using ethyl acetate and crystallisation of the pure fractions from methanol yields 9.46 g (87%) of compound (101) (Table 1), m.p. 127-128° C. Molecular weight C23H25F3O2 (390.45). Analysis, calculated: C 70.75; H 6.45%. Analysis, found: C 70.96; H 6.53%. 1HNMR (300 MHz, CDCl3, ppm): 1.23 (s, 9H); 1.37 (s, 9H); 4.83 (s, 1H); 6.97 (m, 1H); 7.31 (m, 3H); 7.57 (d, 2H).

Provenance & Evidence