反应详情

A 100 mL three-neck flask equipped with a reflux condenser and nitrogen inlet was charged with methyl 4,5,6-trichloropicolinate (2.40 g, 9.98 mmol). Anhydrous THF (50 mL) was added followed by N,N-dimethylethanolamine (0.20 g). The reaction mixture was sparged with nitrogen for 15 min. Solid Pd(PPh3)2Cl2 (140 mg, 0.2 mmol) was added. The reaction mixture was stirred under nitrogen for 20 min. Diethylzinc (1 M solution in hexanes; 10 mL, 10 mmol) was added in 2 mL portions. When starting material was no longer observed through analysis by GC, the reaction mixture was quenched with water and extracted into EtOAc. The combined organic extracts were washed with brine, dried (MgSO4) and concentrated under reduced pressure to a white solid (2.34 g). Analysis by GC-MS showed the solid contained 11% starting methyl 4,5,6-trichloropicolinate. 1H NMR (400 MHz, CDCl3) δ 8.06 (s, 1H, pyridine H), 4.01 (s, 3H, CO2Me), 3.10 (q, J=8 Hz, 2H, CH2), 1.33 (t, J=8 Hz, 3H, CH2CH3); 13C{1H} NMR (101 MHz, CDCl3) δ 164.4, 162.8, 145.4, 143.3, 132.9, 124.5 (C3), 53.1 (CO2Me), 30.0 (CH2), 12.3 (CH2CH3).

1. customA 100 mL three-neck flask equipped with a reflux condenser and nitrogen inlet
2. customThe reaction mixture was sparged with nitrogen for 15 min
3. customthe reaction mixture was quenched with water
4. extractionextracted into EtOAc
5. washThe combined organic extracts were washed with brine
6. dry with materialdried (MgSO4)
7. concentrationconcentrated under reduced pressure to a white solid (2.34 g)