反应详情

Prepared using General Procedure 2. A flask containing 3-cyano-4-isopropoxybenzoic acid (147.7 mg, 0.72 mmol), HOBt (143 mg, 0.94 mmol) and EDC (180 mg, 0.94 mmol) in DMF (2.0 mL) was stirred for 0.5 h at room temperature under an atmosphere of N2. A solution of N-hydroxybenzofuran-5-carboximidamide INT-68 (218 mg, 0.79 mmol) in DMF (2.0 mL) was added to the mixture. After 1 h at room temperature, the mixture was stirred at 85° C. overnight. The reaction mixture was diluted with NaHCO3 and extracted with EA. The combined organic extracts were dried over Na2SO4, and concentrated. The resulting crude material was chromatographed (EA/hexanes) to provide 110 mg (44%) of 5-(3-(benzofuran-5-yl)-1,2,4-oxadiazol-5-yl)-2-isopropoxybenzonitrile 69 as a white solid. LCMS-ESI (m/z) calculated for C20H15N3O3: 345.4; found 346.1 [M+H]+, tR=2.77 min (Method 1). 1H NMR (400 MHz, CDCl3) δ 8.45 (dd, J=4.5, 1.9 Hz, 2H), 8.35 (dd, J=8.9, 2.2 Hz, 1H), 8.12 (dd, J=8.6, 1.7 Hz, 1H), 7.71 (d, J=2.2 Hz, 1H), 7.63 (d, J=8.6 Hz, 1H), 7.13 (d, J=9.0 Hz, 1H), 6.88 (dd, J=2.2, 0.8 Hz, 1H), 4.80 (s, 1H), 1.48 (d, J=6.1 Hz, 61-1).

1. customPrepared
2. waitAfter 1 h at room temperature
3. stirringthe mixture was stirred at 85° C. overnight
4. extractionextracted with EA
5. dry with materialThe combined organic extracts were dried over Na2SO4
6. concentrationconcentrated
7. customThe resulting crude material was chromatographed (EA/hexanes)