Hydrazine → Pyrido(2,3-d)pyridazine-5,8-diol

HRID 1514396Notes

Reaction equation

HRID 1514396 reaction equation
[N:1]1[CH:6]=[CH:5][CH:4]=[C:3]2[C:7](O[C:10](=[O:11])[C:2]=12)=[O:8].[NH2:12][NH2:13]>C(O)(=O)C>[N:1]1[C:2]2[C:10](=[O:11])[NH:12][NH:13][C:7](=[O:8])[C:3]=2[CH:4]=[CH:5][CH:6]=1

Participants

4

Reactant 2

HCID 9321HydrazineHCID 69688Furo[3,4-b]pyridine-5,7-dione

Product 1

HCID 220711Pyrido(2,3-d)pyridazine-5,8-diol

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Conditions

Temperature
125 °C

Procedure

To 25 mL of acetic acid at 100° C. was added 2,3-pyridinedicarboxylic anhydride (5.00 g, 34 mmol). Once the solution was homogeneous, it was removed from the oil bath and anhydrous hydrazine (2.0 ml, 64 mmol) was added dropwise over 5 minutes. The reaction was returned to reflux. After 3 min, the solution crystallized and became a solid mass. The reaction was heated in a 125° C. bath for 10 minutes then cooled to room temperature. The solid was transferred to a Büchner funnel and washed with 2×10 mL of acetic acid. The solid was dried under high vacuum to afford 6,7-dihydropyrido[2,3-d]pyridazine-5,8-dione 77. 1H-NMR (400 MHz, DMSO): δ 9.10 dd, J=4.7, 2.0 Hz, 1H), 8.50 (dd, J=7.8, 1.6 Hz, 1H), 7.86 (dd, J=8.2, 4.7 Hz, 1H).

Workup

  1. additionwas added dropwise over 5 minutes
  2. temperatureto reflux
  3. customthe solution crystallized
  4. temperaturethen cooled to room temperature
  5. washwashed with 2×10 mL of acetic acid
  6. customThe solid was dried under high vacuum

Sources & evidence

ORD record
ord-514b9ddecee64f39932eb9cf71896fcd
Source dataset
uspto-grants-2012_07
Patent number
US08222251B2

Reaction notes

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