Reaction #3195

Reaction equation

dimethyl 4-hydroxyquinoline-2,3-dicarboxylate

hydrazine hydrate

→

hydrazine

Yield 112.8%

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

Yield 112.8%

Solvents

ethanol

Conditions

Workup

1. 1
   workup.DISSOLUTIONdissolved
2. 2
   TemperatureThe resulting solution was refluxed for 3 hr during which time a thick precipitate
3. 3
   Otherformed
4. 4
   OtherThe cooled reaction mixture
5. 5
   Filtrationwas filtered
6. 6
   Washthe collected yellow solids were washed with ethanol
7. 7
   OtherAir drying

Procedure

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).

Source