4-Toluenesulfonyl chloride → HCID 22405677, compound

Participants

Reaction Steps

To an ice-cold solution of 5-[1,2-dioxo-4-(1-methylethoxy)-3-cyclobuten-3-yl]-3-(3-hydroxypropyl]-1-triisopropylsilylindole (12) (0.208 g, 0.44 mmol) in 5 mL of dichloromethane was added p-toluenesulfonyl chloride (0.094 g, 0.49 mmol), followed by triethylamine (68 μL, 0.49 mmol) and a small but arbitrary amount of 4-dimethylaminopyridine. The cooling bath was then removed and the mixture was stirred at room temperature under Ar for 1 h. Another 0.047 g (0.25 mmol) of p-toluenesulfonyl chloride and 34 μL (0.24 mmol) of triethylamine were added and stirring was continued at room temperature for 18 h. The mixture was then diluted with dichloromethane, washed with 10% aqueous Na2CO3, dried (Na2SO4) and evaporated to give a yellow gum. Flash chromatography (SiO2 /CH2Cl2 then hexane-ethyl acetate, 1:1) of this material afforded the title compound (0.265 g, 97%) as a bright yellow gum: IR (neat) 1782, 1738, 1585, 1390 cm-1 ; 1H NMR (CDCl3, 400 MHz) δ 8.34 (d, J=1.5 Hz, 1H), 7.81 (dd, J=8.7, 1.5 Hz, 1H), 7.79 (d, J=8.3 Hz, 2H), 7.56 (d, J=8.7 Hz, 1H), 7.33 (d, J=8.0 Hz, 2H), 7.10 (s, 1H), 5.64 (hept, J=6.2 Hz, 1H), 4.09 (t, J=7.2 Hz, 2H), 2.87 (t, J=7.3 Hz, 2H), 2.44 (s, 3H), 2.11-2.05 (m, 2H), 1.70 (hept, J=7.5 Hz, 3H), 1.58 (d, J=6.1 Hz, 6H), 1.14 (d, J=7.5 Hz, 18H).

Provenance & Evidence