2-Methyl-2-butene → 6-Chloroimidazo[1,2-b]pyridazine-3-carboxylic acid

HRID 870767Notes

Reaction equation

HRID 870767 reaction equation
[Cl:1][C:2]1[CH:3]=[CH:4][C:5]2[N:6]([C:8]([CH:11]=[O:12])=[CH:9][N:10]=2)[N:7]=1.CC(=CC)C.Cl([O-])=[O:19].[Na+]>CC(O)(C)C.C1COCC1.O>[Cl:1][C:2]1[CH:3]=[CH:4][C:5]2[N:6]([C:8]([C:11]([OH:19])=[O:12])=[CH:9][N:10]=2)[N:7]=1

Participants

7

Reactant 3

HCID 105532-Methyl-2-buteneHCID 114467026-Chloroimidazo[1,2-b]pyridazine-3-carbaldehydeHCID 23668197Sodium Chlorite

Product 1

HCID 567666386-Chloroimidazo[1,2-b]pyridazine-3-carboxylic acidYield 67%

Reagents, catalysts & solvents 3

HCID 962WaterSolventHCID 6386tert-ButanolSolventHCID 8028TetrahydrofuranSolvent

Procedure

To a solution of 6-chloroimidazo[1,2-b]pyridazine-3-carbaldehyde (1.82 g, 10 mmol), in t-BuOH (90 mL) and 2-methyl-2-butene in THF (30 mL, 2.0 M) was added a solution of sodium chlorite (80%, 9.0 g, 100 mmol) and NaH2PO4 (1 g, 8 mmol) in water (45 mL). The mixture was stirred at rt for overnight, concentrated, diluted with water, acidified to PH=4, precipitated white solid, filtered to give 6-chloroimidazo[1,2-b]pyridazine-3-carboxylic acid as white solid (1.2 g, 67% yield)). 1H NMR (400 MHz, DMSO-d6) δ ppm 8.29 (d, J=9.60 Hz, 1H), 8.22 (s, 1H), 7.50 (d, J=9.60 Hz, 1H); LRMS (ESI) m/e 198.1 [(M+H)+, calcd for C7H6ClN3O2 198.6].

Workup

  1. concentrationconcentrated
  2. additiondiluted with water
  3. customprecipitated white solid
  4. filtrationfiltered

Sources & evidence

ORD record
ord-d69045a8298a407c8d4812ac994582ae
Source dataset
uspto-grants-2015_03
Patent number
US08969565B2

Reaction notes

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