Thionyl Chloride → 6-(3,6-dichloro-pyridazine-4-carbonyl)-4-methyl-3H-benzoxazol-2-one

HRID 469324Notes

Reaction equation

HRID 469324 reaction equation
S(Cl)(Cl)=O.[Cl:5][C:6]1[N:7]=[N:8][C:9]([Cl:15])=[CH:10][C:11]=1[C:12](O)=[O:13].[Cl-].[Cl-].[Cl-].[Al+3].[CH3:20][C:21]1[C:26]2[NH:27][C:28](=[O:30])[O:29][C:25]=2[CH:24]=[CH:23][CH:22]=1>ClCCCl>[Cl:5][C:6]1[N:7]=[N:8][C:9]([Cl:15])=[CH:10][C:11]=1[C:12]([C:23]1[CH:22]=[C:21]([CH3:20])[C:26]2[NH:27][C:28](=[O:30])[O:29][C:25]=2[CH:24]=1)=[O:13]

Participants

6

Reactant 4

HCID 24386Thionyl ChlorideHCID 4338043,6-Dichloropyridazine-4-carboxylic acidHCID 6451240Aluminum(III) ChlorideHCID 127093364-Methyl-3H-benzooxazol-2-one

Product 1

HCID 581811846-(3,6-dichloro-pyridazine-4-carbonyl)-4-methyl-3H-benzoxazol-2-one

Reagents, catalysts & solvents 1

HCID 111,2-DichloroethaneSolvent

Conditions

Temperature
100 °C

Procedure

2.00 mL (27.4 mmol) thionyl chloride were added to 1.92 g (9.95 mmol) 3,6-dichloro-pyridazine-4-carboxylic acid in 10 mL 1,2-dichloroethane and the mixture was refluxed for 2 h. The reaction mixture was evaporated to dryness and coevaporated with 1,2-dichloroethane. Then 5.30 g (39.8 mmol) aluminium trichloride and 1.56 g (10.5 mmol) 4-methyl-3H-benzoxazol-2-one were added and the mixture was stirred for 1 h at 100° C. under a nitrogen atmosphere. Then it was stirred for a further 2 h at 120° C., 3 h at 130° C. and then cooled for 48 h at RT. The mixture was decomposed with ice water and extracted with DCM. The organic phases were combined, washed with water, dried on sodium sulphate, filtered and evaporated down i. vac. The residue was triturated with DIPE, suction filtered and dried.

Workup

  1. temperaturethe mixture was refluxed for 2 h
  2. customThe reaction mixture was evaporated to dryness
  3. stirringThen it was stirred for a further 2 h at 120° C., 3 h at 130° C.
  4. temperaturecooled for 48 h at RT
  5. extractionextracted with DCM
  6. washwashed with water
  7. customdried on sodium sulphate
  8. filtrationfiltered
  9. customevaporated down i
  10. customThe residue was triturated with DIPE, suction
  11. filtrationfiltered
  12. customdried

Sources & evidence

ORD record
ord-cc30edbc4c1543d59c80220e9fc8cade
Source dataset
uspto-grants-2014_01
Patent number
US08629137B2

Reaction notes

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