Sulfuric Acid → 3,6-Dichloro-4-cyclobutylpyridazine

HRID 380321

Reaction equation

HRID 380321 reaction equation
[Cl:1][C:2]1[N:3]=[N:4][C:5]([Cl:8])=[CH:6][CH:7]=1.OS(O)(=O)=O.[CH:14]1(C(O)=O)[CH2:17][CH2:16][CH2:15]1>O>[Cl:1][C:2]1[N:3]=[N:4][C:5]([Cl:8])=[CH:6][C:7]=1[CH:14]1[CH2:17][CH2:16][CH2:15]1

Participants

5

Reactant 3

HCID 1118Sulfuric AcidHCID 19494Cyclobutanecarboxylic acidHCID 673313,6-Dichloropyridazine

Product 1

HCID 219732193,6-Dichloro-4-cyclobutylpyridazineYield 98.3%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Conditions

Temperature
70 °C

Procedure

3,6-Dichloropyridazine (10 g) was suspended in water (200 ml), H2SO4 (19.7 g) and cyclobutane carboxylic acid (32.7 g) were added and the reaction degassed under N2 at 70° C. Silver nitrate (2.28 g) was added followed by dropwise addition of ammonium persulfate (45.9 g) in water (120 ml). After an additional 1 hour heating at 70° C., the reaction was poured onto ice, basified to pH 8-9 with aqueous ammonium hydroxide and extracted into ethyl acetate (3×500 ml), dried (MgSO4) and evaporated to dryness. Purified with hexane-ethyl acetate mixtures to obtain pure product (13.4 g). 1H NMR (360 MHz , CDCl3) δ 1.57 (2H, m), 1.82 (4H, m), 2.20 (1H, m), 3.30 (1H, m), 7.38 (1H, s); MS (ES+) m/e 217 [MH]+.

Workup

  1. customthe reaction degassed under N2 at 70° C
  2. additionSilver nitrate (2.28 g) was added
  3. additionfollowed by dropwise addition of ammonium persulfate (45.9 g) in water (120 ml)
  4. additionthe reaction was poured onto ice
  5. extractionextracted into ethyl acetate (3×500 ml)
  6. dry with materialdried (MgSO4)
  7. customevaporated to dryness
  8. customPurified with hexane-ethyl acetate mixtures

Sources & evidence

ORD record
ord-3671f2e139124d1da48098d0c6ba8df0
Source dataset
uspto-grants-2001_10
Patent number
US06303605B1

Linked notes

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