6-Amino-3-chloropyridazine → 6-Chloro-2-cyclopropylimidazo[1,2-b]pyridazine

HRID 1926781Notes

Reaction equation

HRID 1926781 reaction equation
[Cl:1][C:2]1[N:7]=[N:6][C:5]([NH2:8])=[CH:4][CH:3]=1.Br[CH2:10][C:11]([CH:13]1[CH2:15][CH2:14]1)=O>C(COC)OC>[Cl:1][C:2]1[CH:3]=[CH:4][C:5]2[N:6]([CH:10]=[C:11]([CH:13]3[CH2:15][CH2:14]3)[N:8]=2)[N:7]=1

Participants

4

Reactant 2

HCID 216436-Amino-3-chloropyridazineHCID 109208412-Bromo-1-cyclopropylethan-1-one

Product 1

HCID 536291716-Chloro-2-cyclopropylimidazo[1,2-b]pyridazineYield 42%

Reagents, catalysts & solvents 1

HCID 80711,2-DimethoxyethaneSolvent

Procedure

A mixture of 6-chloropyridazin-3-amine x104 (24.63 g, 0.19 mol) and 2-bromo-1-cyclopropylethanone (31 g, 0.190 mol, 1 eq) in dimethoxyethane (400 ml) is refluxed under inert atmosphere for 2 days. After cooling to room temperature, the solvent is removed under reduced pressure, the crude is taken up in water (100 ml) and extracted with ethyl acetate (2×300 ml). The cumulated organic layers are dried over MgSO4, filtered and condensed under reduced pressure to furnish 6-chloro-2-cyclopropylimidazo[1,2-b]pyridazine x105 (Yield: 42%) which is used as such in the next step. Note that further title compound x105 can be extracted from aqueous layer after neutralization to pH 5 by addition of sodium hydroxyde, extraction with dichloromethane, drying (MgSO4), filtration and condensation under reduced pressure (additional 11.13 g are then collected).

Workup

  1. temperatureis refluxed under inert atmosphere for 2 days
  2. customthe solvent is removed under reduced pressure
  3. extractionextracted with ethyl acetate (2×300 ml)
  4. dry with materialThe cumulated organic layers are dried over MgSO4
  5. filtrationfiltered
  6. customcondensed under reduced pressure

Sources & evidence

ORD record
ord-4a5d697eb60f4948baa0cb54c181a353
Source dataset
uspto-grants-2012_05
Patent number
US08183241B2

Reaction notes

Loading…