反应详情

To 2-fluoro-6-nitrobenzoic acid (712 mg, 3.85 mmol) in methanol/acetonitrile (10 mL/10 mL) was dropwise added TMSCHN2 at 0° C. under N2 until yellow color persistent, and stirred additional 30 min. Then the reaction was quenched with HOAcat 0° C. until the yellow color disappears. Partial of the solvent was removed o rotary vacuum, the residue was dissolved in small amount of EtOAc, purified on flash chromatography eluting with 30˜50% EtOAc/hexanes (600 mL) to afford the expected product, methyl 2-fluoro-6-nitrobenzoate, (716 mg, 94% yield) which was used in step-2; 1H NMR (400 MHz, CDCl3) δ ppm 3.96 (s, 3 H), 7.40-7.48 (m, 1 H), 7.58 (td, J=8.31, 5.54 Hz, 1 H), 7.94 (d, J=8.31 Hz, 1 H); Mass spec. 200.05 (MH+), Calc. for C8H6FNO4 199.03.

1. customat 0° C.
2. customThen the reaction was quenched with HOAcat 0° C. until the yellow color
3. customPartial of the solvent was removed o rotary vacuum
4. dissolutionthe residue was dissolved in small amount of EtOAc
5. custompurified on flash chromatography
6. washeluting with 30˜50% EtOAc/hexanes (600 mL)