反应详情

To a solution of 6-bromo-2-(tetrahydro-2H-pyran-3-yl)chroman-4-one (300 mg, 0.98 mmol) in anhydrous DCM (8 mL) was added TiCl4 (1 M solution in DCM, 1.96 mL, 1.96 mmol) dropwise within 15 min at room temperature. It was stirred for 1 h after the addition. To this mixture was added bis-trimethylsilylcarbodiimide (400.7 mg, 2.15 mmol) dropwise. The resulting mixture was stirred for 18 h after the addition. The reaction mixture was poured into ice-water (100 g) and extracted with DCM (3×50 mL). The combined organic phases were dried over anhydrous Na2SO4, filtered, and concentrated to give (E)-N-(6-bromo-2-(tetrahydro-2H-pyran-3-yl)chroman-4-ylidene)cyanamide (300 mg, 100%), which was used in next step without further purification.

1. additionafter the addition
2. stirringThe resulting mixture was stirred for 18 h
3. additionafter the addition
4. extractionextracted with DCM (3×50 mL)
5. dry with materialThe combined organic phases were dried over anhydrous Na2SO4
6. filtrationfiltered
7. concentrationconcentrated