反应详情

Ethyl 5-chloro-3-(phenylacetamido)picolinate (153) was formed by reacting ethyl 3-aminopicolinate and phenacetyl chloride under the conditions described in Example 3. The amide (153) (10.0 mg, 0.0324 mmol) was added to a CH2Cl2 solution (10 mL) of methyl(trifluoromethyl)dioxirane, generated from 2.5 mL of 1,1,1-trifluoroacetone using the procedure of Mello et al. (Mello et al., J. Amer. Chem. Soc. 111:6749-6757 (1989)). The solution was stirred at rt in a bomb protected from light. After 4 days, the solvent was removed and the residue chromatographed by prep TLC (silica GF). Eluting with hexanes-EtOAc (1:4), the band at Rf =0.45 was removed and triturated with MeOH (40 mL) overnight. The mixture was filtered and the filtrate rota-evaporated to dryness, leaving a white residue (0.4 mg, 4%). 1H NMR (CDCl3): δ1.26 (t, J=7.2, 3, CH3CH2), 3.75 (s, 2, benzylic), 4.10 (q, J=7.2, 2, CH3CH2O), 7.37 (m, 5, phenyl), 7.98 (d, J=0.9, 1, py), 8.44 (s, 1, py); LRMS (m/z):336 (5), 335 (5), 334 (M+, 20), 274 (15), 273 (10), 272 (55), 260 (10), 226 (10), 180 (10), 156 (10), 154 (30), 126 (10), 117 (20), 91 (100), 65 (15); HRMS Calcd for C16H15ClN2O4 : 334.0720, Found: 334.0729; HPLC: 77%.

1. customthe solvent was removed
2. customthe residue chromatographed by prep TLC (silica GF)
3. washEluting with hexanes-EtOAc (1:4)
4. customthe band at Rf =0.45 was removed
5. customtriturated with MeOH (40 mL) overnight
6. filtrationThe mixture was filtered
7. customthe filtrate rota-evaporated to dryness