Tetrahydrofuran → 2-Dimethylaminopyridine

Participants

Reaction Conditions

Reaction Steps

2-Amino-1,2,4 thiadiazole (0.006 g, 0.06 mmol) and triethylamine (0.0376 mL, 0.27 mmol) were added to 1 mL dichloromethane and cooled to 0° C. To this was slowly added chlorosulfonylisocyanate (0.007 mL, 0.08 mmol) at 0° C. Stirred thirty minutes until starting material consumed. Simultaneously, in a separate flask trimethylsilylethyl ether 44 was dissolved in 0.5 mL tetrahydrofuran. To this was added triethylamine (0.0376 mL, 0.27 mmol) and 1M tetrabutylammonium fluoride in tetrahydrofuran (0.135, 0.135 mmol) and stirred at room temperature. After 20 minutes, diluted with dichloromethane, washed with 1M HCl solution and brine, concentrated to give crude. At 0° C., dissolved in 0.5 mL dichloromethane and added to the solution prepared in situ above. Stirred at 0° C. for Sminutes, catalytic DMAP added, then stirred for one hour at room temperature. Diluted with dichloromethane, washed with 1M HCl solution, brine, concentrated to give crude. Chromatographed (5 to 30% methanol/dichloromethane) to give dimethylaminopyridine adduct 227 (0.033 g, 0.046 mmol, 68%.) 1H NMR (CDCl3) δ 8.97 (dd, 1H), 8.54 (d, 2H), 8.19 (d, 1H), 8.00 (s, 1H), 7.72 (d, 4H), 7.42 (dd, 1H), 7.26-7.14 (m, 7H), 7.02 (dd, 2H), 6.52 (d, 2H), 4.74 (s, 2H), 4.17 (s, 2H), 3.22 (s, 6H.) MS: 718 (M+1).

Provenance & Evidence