Reaktion #3202

Reaktionsgleichung

methyl 2-amino-6-methylbenzoate

dimethyl acetylenedicarboxylate

potassium t-butoxide

→

title compound

Ausbeute 66.4%

Dimethyl 4-hydroxy-5-methylquinoline-2,3-dicarboxylate

Ausbeute 66.4%

Lösungsmittel

t-butanol

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturwas refluxed fpr 18 hr under a nitrogen atmosphere
2. 2
   Sonstigeformed
3. 3
   TemperaturAfter refluxing this mixture for 1.5 hr
4. 4
   Temperaturit was cooled to room temperature
5. 5
   Filtrationfiltered
6. 6
   Sonstigeto separate the solids
7. 7
   workup.DISSOLUTIONThe solids were dissolved in water
8. 8
   Sonstigeto form a precipitate
9. 9
   FiltrationThe mixture was filtered
10. 10
    Waschenthe collected solids were washed with water
11. 11
    Sonstigedried

Vorschrift

A stirred mixture of methyl 2-amino-6-methylbenzoate (1.50 g, 9.08 mM) and dimethyl acetylenedicarboxylate (1.40 g, 9.82 mM) in t-butanol (20 mL) was refluxed fpr 18 hr under a nitrogen atmosphere. The reaction mixture was cooled to room temperature and potassium t-butoxide (1.10 g, 9.82 mM) was added in one portion whereupon a precipitate formed. After refluxing this mixture for 1.5 hr, it was cooled to room temperature and filtered to separate the solids. The solids were dissolved in water and the resulting solution acidified with 1N H2SO4 to form a precipitate. The mixture was filtered and the collected solids were washed with water and dried to give the title compound (1.66 g, 66.4%) as a tan solid. An analytical sample of this material was obtained by recrystallization of a portion from ethyl acetate/hexane to give off white crystals, mp 167°-168° C.; MS(CI): 276 (M+H).

Quelle