HCID 20269042, compound → HCID 20269034, compound

HRID 485686Notes

Reaction equation

HRID 485686 reaction equation
[CH2:1]([O:3][C:4]([C:6]1[C:10](=[O:11])[NH:9][N:8]([C:12]2[CH:17]=[CH:16][C:15](N)=[CH:14][CH:13]=2)[CH:7]=1)=[O:5])[CH3:2].N([O-])=[O:20].[Na+]>S(=O)(=O)(O)O.O>[CH2:1]([O:3][C:4]([C:6]1[C:10](=[O:11])[NH:9][N:8]([C:12]2[CH:17]=[CH:16][C:15]([OH:20])=[CH:14][CH:13]=2)[CH:7]=1)=[O:5])[CH3:2]

Participants

5

Reactant 2

HCID 20269042HCID 20269042, compoundHCID 23668193Sodium Nitrite

Product 1

HCID 20269034HCID 20269034, compoundYield 16.5%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 1118Sulfuric AcidSolvent2×

Conditions

Temperature
0 °C

Procedure

4-Ethoxycarbonyl-2-(4-amino phenyl)-3-pyrazolin-5-one (610 mg, 2.46 mmol) in 5N Sulphuric acid (90 ml) was stirred on a boiling water bath to give a solution. This was cooled to 0° C. and the colloidal precipitate formed treated with sodium nitrite (190 mg, 2.71 mmol) in water (2 ml). The whole was then allowed to stir for 2 hours at 0° C. under nitrogen and then added dropwise to boiling 5N sulphuric acid (30 ml) so as not to interrupt boiling. The solution was then allowed to cool and was extracted with ethyl acetate which, after drying (MgSO4) and evaporation, gave the crude product (190 mg). This was purified by chromatography on silica (hexane; ethyl acetate) to give the desired product (101 mg) νmax (KBr Disc) 1660, 1595, 1520, 1433, 1277, 1140 cm-1, δ(D6 -Acetone) 1.33(3H, t, J7 Hz,--OCH2CH3), 3.30(1H, br), 4.33(2H,q,J7 Hz--OCH2CH3), 6.94 (2H, d, J9 Hz, protons o--OH), 7.65 (2H,d, J9 Hz, protons m--OH), 8.44 (1H, s, C3 pyrazole proton), 8.75 (1H, brs); Found: M+, 248.0773; C12H12N2O4 requires M, 248.0797. Calculated: C,58.1; H,4.8; N,11.3, Found: C, 58.3; H,5.1; N, 11.0

Workup

  1. customto give a solution
  2. customthe colloidal precipitate formed
  3. additionadded dropwise
  4. temperatureto cool
  5. extractionwas extracted with ethyl acetate which
  6. customafter drying
  7. custom(MgSO4) and evaporation
  8. customgave the crude product (190 mg)
  9. customThis was purified by chromatography on silica (hexane; ethyl acetate)

Sources & evidence

ORD record
ord-cbb77a59ab6e40e9a71133dcce3de3a4
Source dataset
uspto-grants-1985_08
Patent number
US04537886

Reaction notes

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