Formic Acid → (S)-4-bromo-7-fluoro-2,3-dihydro-1H-inden-1-ol

Participants

Reaction Conditions

Reaction Steps

20.0 g (87.3 mmol) 4-bromo-7-fluoro-2,3-dihydro-1H-inden-1-one, 142 ml toluene and 13.9 g (138 mmol) TEA are added into a vessel. The mixture is degassed and heated to 40° C. Then, 272 mg (0.44 mmol) chloro{[(1S,2S)-(−)-2-amino-1,2-diphenylethyl](4-toluenesulfonyl)amido}-(mesitylene)ruthenium(II) is added before a mixture of 7.03 g (153 mmol) formic acid (98%) and 3.00 mL toluene is added over a time period of 60 min. The funnel is rinsed with 7.00 ml toluene. Stirring is continued at 40° C. for approx. 90 min until full conversion (HPLC). 1.43 g (8.73 mmol) N-acetyl-L-cystein is added and stirring is continued for 30 min. A mixture of 15.8 g (160 mmol) conc. HCl in 24 ml water is added and the aqueous phase is separated. The organic phase is washed with 35.0 ml water and 140 ml solvent is distilled off. 90 ml IPA is added and 70 ml solvent is distilled off. To the residue 50 ml water is added and the mixture is cooled to 35° C. Then, seeds are added followed by 50 ml water. The suspension is cooled to 22° C. and stirred for 2 h. The product is filtered off, washed with water (2×30 ml) and dried. Yield: 18.6 g; LC (method 1): tR=0.91 min; Mass spectrum (ESI+): m/z=213 [M+H—H2O]+.

Provenance & Evidence