Potassium Hydroxide → (S)-1,2,3,4,6,11-Hexahydro-6,11-dioxopyridazino[1,2-b]phthalazine-1-carboxylic acid

HRID 2217190Notes

Reaction equation

HRID 2217190 reaction equation
C[O:2][C:3]([C@H:5]1[N:10]2[C:11](=[O:20])[C:12]3[C:17]([C:18](=[O:19])[N:9]2[CH2:8][CH2:7][CH2:6]1)=[CH:16][CH:15]=[CH:14][CH:13]=3)=[O:4].[OH-].[K+]>CO>[O:19]=[C:18]1[C:17]2[C:12](=[CH:13][CH:14]=[CH:15][CH:16]=2)[C:11](=[O:20])[N:10]2[C@H:5]([C:3]([OH:4])=[O:2])[CH2:6][CH2:7][CH2:8][N:9]12

Participants

4

Reactant 2

HCID 14797Potassium HydroxideHCID 59767867HCID 59767867, compound

Product 1

HCID 22856663(S)-1,2,3,4,6,11-Hexahydro-6,11-dioxopyridazino[1,2-b]phthalazine-1-carboxylic acid

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent2×

Procedure

To a stirred solution of (S)-6,11-dioxo-1,2,3,4-tetrahydro-pyridazino[1,2-b]phthalazin-1-carboxylic acid methyl ester (1.078 g, 3.93 mmol) in MeOH (35 mL) was added KOH (232 mg, 4.12 mmol) in MeOH (11 mL) at 0° C. The reaction mixture was allowed to warm to room temperature and stirred for 20 hours, then concentrated under reduced pressure. The residue was dissolved in ethyl acetate and the resulting solution was extracted with water. The aqueous phase was acidified with 2.0-M HCl then extracted several times with ethyl acetate. The combined organic extracts were dried (MgSO4), filtered and concentrated. The residue was crystallized from diethyl ether and the title compound was obtained as a white solid (744 mg, 73%): 1H NMR (400 MHz, CD3OD) δ 1.80 (1H, m), 1.97 (1H, m), 2.16 (1H, m), 2.56 (1H, m), 3.36 (1H, m), 4.83-4.88 (2H, m), 5.71 (1H, m), 7.90 (2H, m), 8.26 (2H, m).

Workup

  1. concentrationconcentrated under reduced pressure
  2. dissolutionThe residue was dissolved in ethyl acetate
  3. extractionthe resulting solution was extracted with water
  4. extractionthen extracted several times with ethyl acetate
  5. dry with materialThe combined organic extracts were dried (MgSO4)
  6. filtrationfiltered
  7. concentrationconcentrated
  8. customThe residue was crystallized from diethyl ether

Sources & evidence

ORD record
ord-a5b1823e428e4bbdaf9409025dcf55b3
Source dataset
uspto-grants-2008_08
Patent number
US07407964B2

Reaction notes

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