Reaktion #3195

Reaktionsgleichung

dimethyl 4-hydroxyquinoline-2,3-dicarboxylate

hydrazine hydrate

→

hydrazine

Ausbeute 112.8%

2,3-Dihydro-10-hydroxypyridazino[4,5-b]quinoline-1,4-dione

Ausbeute 112.8%

Lösungsmittel

ethanol

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.DISSOLUTIONdissolved
2. 2
   TemperaturThe resulting solution was refluxed for 3 hr during which time a thick precipitate
3. 3
   Sonstigeformed
4. 4
   SonstigeThe cooled reaction mixture
5. 5
   Filtrationwas filtered
6. 6
   Waschenthe collected yellow solids were washed with ethanol
7. 7
   SonstigeAir drying

Vorschrift

To a stirred suspension of dimethyl 4-hydroxyquinoline-2,3-dicarboxylate (1.00 g, 3.83 mM, prepared as described by H. Biere and W. Seelen, Liebigs Ann. Chem. 1976, 1972) in ethanol (15 mL) was added hydrazine hydrate (9.64 g, 193 mM) whereupon the solids dissolved. The resulting solution was refluxed for 3 hr during which time a thick precipitate formed. The cooled reaction mixture was filtered and the collected yellow solids were washed with ethanol and then ether. Air drying provided 0.99 g of the hydrazine salt of 2,3-dihydro-10-hydroxypyridazino[4,5-b]quinoline-1,4-dione. This material was boiled in glacial acetic acid (40 mL) and, after cooling to room temperature, the mixture was filtered. The collected solids were washed with several portions of ethyl acetate and then ether. Air drying provided the title pyridazinodione (0.72 g, 82%) as a yellow solid, mp>400° C.; Mass Spectrum (Chemical Ionization): 230 (M+H).

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