2-Chloro-6-methylpyridine-4-carboxylic acid → 2-Chloro-6-methyl-isonicotinic acid tert-butyl ester
반응식
C([O:5][CH:6]([O:10][C:11]([CH3:14])([CH3:13])[CH3:12])N(C)C)(C)(C)C.[Cl:15][C:16]1[CH:17]=[C:18]([CH:22]=[C:23]([CH3:25])[N:24]=1)C(O)=O>C1(C)C=CC=CC=1>[C:11]([O:10][C:6](=[O:5])[C:18]1[CH:22]=[C:23]([CH3:25])[N:24]=[C:16]([Cl:15])[CH:17]=1)([CH3:12])([CH3:13])[CH3:14]참가 물질
4
반응 조건
- 온도
- 80 °C
실험 절차
N,N-dimethylformamide-di-tert.-butyl-acetal (19 mL, 80 mmol) is added during 40 min to a hot (65° C., flask temperature) suspension of 2-chloro-6-methyl-isonicotinic acid (3.40 g, 19.8 mmol) in dry toluene (100 mL). The clear orange solution is stirred at 80° C. for 48 h, cooled to rt and diluted with toluene (100 mL). The solution is washed with water (2×40 mL), sat. aq. NaHCO3 (3×30 mL) and sat. aq. NaCl (25 mL), dried (Na2SO4), filtered and evaporated. The residue is purified by FC (SiO2, DCM-MeOH) to give 2-chloro-6-methyl-isonicotinic acid tert-butyl ester.