反应详情

温度

0 °C

N-tritylimidazole-2-carboxaldehyde (338 mg, 1 mmol, prepared according to K. L. Kirk; J.Org.Chem., 1978, 43, 4381) was dissolved in dry toluene (7 mL) and anhydrous magnesium sulfate (602 mg, 5 mmol) added with stirring under nitrogen. Benzylamine (131 μL, 1.2 mmol) was added and the solution stirred for 3.5 hr. The solids were filtered under nitrogen and the reaction concentrated. The residue is redissolved in 1,2-dichloroethane (25 mL) and cooled to 0° C. Sodium triacetoxyborohydride (1.06 g, 5 mmol) was added slowly. The solution was allowed to warm to room temperature over 2.5 hours. The reaction mixture was added to water/ethyl acetate and the layers separated. The aqueous layer was extracted with two portions of ethyl acetate and the combined organic layers washed with sat. bicarbonate, water, and brine. The solution was concentrated to an oil and purified by flash chromatography on silica gel (99:1 EtOAc/EtOH with 0.1% triethylamine) to afford 330 mg (77%) of product as an oil which solidified on standing. LRMS (ES): 430.4 [M+H]+, 243.2; 1HNMR (600.1328 MHz, DMSO-d6): 7.37 (m, 11H), 7.04 (m, 9 H), 6.92 (d, 1H), 6.64 (d, 1H), 3.34 (s, 2H), 2.77 (2H).

1. stirringthe solution stirred for 3.5 hr
2. filtrationThe solids were filtered under nitrogen
3. concentrationthe reaction concentrated
4. dissolutionThe residue is redissolved in 1,2-dichloroethane (25 mL)
5. temperatureto warm to room temperature over 2.5 hours
6. customthe layers separated
7. extractionThe aqueous layer was extracted with two portions of ethyl acetate
8. washthe combined organic layers washed with sat. bicarbonate, water, and brine
9. concentrationThe solution was concentrated to an oil
10. custompurified by flash chromatography on silica gel (99:1 EtOAc/EtOH with 0.1% triethylamine)