Sulfuric acid magnesium salt (1:1) → Azulene

HRID 1531253

Reaction equation

HRID 1531253 reaction equation
[C:1]1(C=O)[C:10]2[C:4]([CH:5]=[CH:6][CH:7]=[CH:8][CH:9]=2)=[C:3](C=O)[CH:2]=1.S([O-])([O-])(=O)=O.[Mg+2].Cl.C(NO)(C)(C)C.C([O-])(O)=O.[Na+]>N1C=CC=CC=1.C(Cl)(Cl)Cl>[CH:1]1[C:10]2[C:4]([CH:5]=[CH:6][CH:7]=[CH:8][CH:9]=2)=[CH:3][CH:2]=1

Participants

7

Reactant 4

HCID 24083Sulfuric acid magnesium salt (1:1)HCID 516892Sodium BicarbonateHCID 2777896N-tert-butylhydroxylamine hydrochlorideHCID 109761521,3-Azulenedicarboxaldehyde

Product 1

HCID 9231AzuleneYield 225.1%

Reagents, catalysts & solvents 2

HCID 1049PyridineSolventHCID 6212ChloroformSolvent

Conditions

Temperature
95 °C

Procedure

1,3-Azulenedicarboxaldehyde (600 mg) is dissolved in 6.5 ml of pyridine. Magnesium sulfate (1200 mg) and N-tert-butylhydroxylamine hydrochloride (1638 mg) is added to the solution. The mixture is heated with stirring to 95° C. under nitrogen and is stirred for 13 hours. Upon cooling to rt, the reaction mixture is poured into a separator funnel containing 60 ml of CHCl3 and 60 ml of sat aq. NaHCO3. The aqueous layer is separated and washed with three 30 ml portions of CHCl3. The combined organic layers are dried over anhydrous MgSO4, filtered, and evaporated to give the bis-nitrone 34 (940 mg, 89% yield) as dark green crystals. Oxidation potential equals 0.72 V vs SCE. 1H NMR (CDCl3): 10.35 (s, 1H), 8.65 (d, 2H, J=10 Hz) 8.11 (s, 2H), 7.68 (t, 1H, J=10 Hz), 7.32 (t, 2H, J=10 Hz), 1.67 (s, 18H). 13C NMR (CDCl3): 139.9, 135.0, 134.2, 125.8, 125.6, 123.2, 120.5, 69.8, 28.4. IR (thin film): 3052, 2972, 1644, 1564, 1452, 1404, 1356, 1261, 1196, 1124, 1052, and 892 cm−1.

Workup

  1. temperatureThe mixture is heated
  2. stirringis stirred for 13 hours
  3. temperatureUpon cooling to rt
  4. additionthe reaction mixture is poured into a separator funnel
  5. customThe aqueous layer is separated
  6. washwashed with three 30 ml portions of CHCl3
  7. dry with materialThe combined organic layers are dried over anhydrous MgSO4
  8. filtrationfiltered
  9. customevaporated

Sources & evidence

ORD record
ord-d704c78ec6494293b1938c43139303a8
Source dataset
uspto-grants-2001_03
Patent number
US06197825B1

Linked notes

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