Tetrabutylammonium Fluoride → HCID 11157447, compound

Participants

Reaction Conditions

Reaction Steps

To a solution of 0.081 g of 4-(3′-cyano-biphenyl-4-yl)-4-[5,6-dichloro-1-(2-trimethylsilanyl-ethoxymethyl)-1H-benzoimidazol-2-yloxymethyl]-piperidine-1-carboxylic acid tert-butyl ester 52 (0.115 mmol) in 5 mL of tetrahydrofuran at room temperature was added 0.23 mL of a solution of TBAF (1M in THF, 0.23 mmol, 2 eq). The mixture was heated at 60° C. for 6 h. After cooling to room temperature, the mixture was partitioned between 15 mL of ethyl acetate and 15 mL of H2O. The organic layer was separated, washed with saturated brine, dried (Na2SO4), and concentrated by rotary evaporation to give the crude product as a pale foam (0.070 g) which was purified by flash column chromatography eluting with 30% ethyl acetate in hexanes to give 0.035 g of 4-(3′-cyano-biphenyl-4-yl)-4-(5,6-dichloro-1H-benzoimidazol-2-yloxymethyl)-piperidine-1-carboxylic acid tert-butyl ester 53 as a pale foam and 0.024 g of recovered starting material. 1H NMR (300 MHz, CDCl3): δ 7.82-7.75 (m, 2H), 7.64-7.52 (dt, 1H), 7.61-7.46 (m, 5H), 7.26 (s, 1H), 4.51 (s, 2H), 3.85-3.83 (d, 2H), 3.18-3.10 (t, 2H), 2.32-2.28 (d, 2H), 2.04-1.98 (t, 2H), 1.42 (s, 9H). MS (ESI): Calcd m/z for C31H30Cl2N4O3.H+=577.2. Found m/z=576.7/578.7 [(M+1)+/(M+3)+].

Provenance & Evidence