반응 #3196

반응 방정식

potassium t-butoxide

methyl 2-amino-4-chlorobenzoate

dimethyl acetylenedicarboxylate

dimethyl acetylenedicarboxylate

→

dimethyl 7-chloro-4-hydroxyquinoline-2,3-dicarboxylate

수율 28.9%

용매

t-butanol

반응 조건

후처리

1. 1
   온도was refluxed for 7 hr under a nitrogen atmosphere
2. 2
   온도refluxing another 2.5 hr
3. 3
   기타A precipitate formed
4. 4
   온도the resulting mixture was refluxed for 1.5 hr
5. 5
   온도The mixture was cooled to room temperature
6. 6
   여과filtered
7. 7
   기타to separate the solids, which
8. 8
   세척were washed with t-butanol and ether
9. 9
   workup.DISSOLUTIONThe solids were dissolved in water
10. 10
    기타to form a precipitate
11. 11
    추출The resulting mixture was extracted with methylene chloride
12. 12
    세척the combined extracts were washed with brine and water
13. 13
    건조dried (MgSO4)
14. 14
    여과filtered
15. 15
    농축concentrated
16. 16
    기타to give a green solid
17. 17
    기타Recrystallization of this material from methanol

실험 절차

A stirred mixture of methyl 2-amino-4-chlorobenzoate (2.50 g, 13.5 mM) and dimethyl acetylenedicarboxylate (2.05 g, 14.4 mM) in t-butanol (22 mL) was refluxed for 7 hr under a nitrogen atmosphere. After adding additional dimethyl acetylenedicarboxylate (1.16 g, 8.13 mM) and refluxing another 2.5 hr, the reaction mixture was allowed to cool to room temperature and potassium t-butoxide (1.56 g, 13.9 mM) was added in one portion. A precipitate formed and the resulting mixture was refluxed for 1.5 hr. The mixture was cooled to room temperature and filtered to separate the solids, which were washed with t-butanol and ether. The solids were dissolved in water and acidified with 1N sulfuric acid to form a precipitate. The resulting mixture was extracted with methylene chloride and the combined extracts were washed with brine and water, dried (MgSO4), filtered and concentrated to give a green solid. Recrystallization of this material from methanol provided dimethyl 7-chloro-4-hydroxyquinoline-2,3-dicarboxylate (1.15 g, 28.9%) as an off-white solid, mp 232-233° C.; MS(CI): 296 (M+H).

출처