Hydrochloric Acid → 2-tert-butyl-5-chloro-4-methylpyridazin-3-(2H)-one

HRID 1904230Notes

Reaction equation

HRID 1904230 reaction equation
[Mg].[CH3:2]I.[C:4]([N:8]1[C:13](=[O:14])[C:12](Cl)=[C:11]([Cl:16])[CH:10]=[N:9]1)([CH3:7])([CH3:6])[CH3:5].Cl>O1CCCC1.C1(C)C=CC=CC=1>[C:4]([N:8]1[C:13](=[O:14])[C:12]([CH3:2])=[C:11]([Cl:16])[CH:10]=[N:9]1)([CH3:7])([CH3:6])[CH3:5]

Participants

7

Reactant 4

HCID 313Hydrochloric AcidHCID 6328Methyl iodide3×HCID 27822252-Tert-butyl-4,5-dichloro-2,3-dihydropyridazin-3-oneHCID 5462224Magnesium2×

Product 1

HCID 138222642-tert-butyl-5-chloro-4-methylpyridazin-3-(2H)-one

Reagents, catalysts & solvents 2

HCID 1140TolueneSolvent2×HCID 8028TetrahydrofuranSolvent

Procedure

To a solution of 6.0 g (0.25 mol) of magnesium in 50 ml of dry tetrahydrofuran was added dropwise under stream of nitrogen 35.5 g (0.25 mol) of methyl iodide to prepare a Grignard reagent. After dropwise addition of the methyl iodide, 1000 ml of dry toluene was added thereto. The resulting solution was heated at 60° to 70° C. and additional methyl iodide was added thereto until the magnesium completely disappeared. The Grignard reagent was cooled to room temperature and then added dropwise over 20 minutes with a solution of 22.1 g (0.1 mol) of 2-t-butyl-4,5-dichloro-3(2H)-pyridazinone in 200 ml of dry toluene. After dropwise addition, the resulting mixture was subjected to reaction at room temperature for 1.5 hours. The reaction liquid was poured into a solution of 100 ml of concentrated hydrochloric acid in 900 ml of ice water to effect extraction. The resulting organic layer was washed with 500 ml of a 10% sodium hydroxide solution and then with 500 ml of water, and then dried over anhydrous sodium sulfate. Solvent was distilled off therefrom under reduced pressure to give 17.2 g of a crude product. The crude product was subjected to distillation (boiling point: 60° to 62° C./0.22 mmHg) and then to column chromatography [on silica gel; eluting with hexane-acetone (15:1)] for separation and purification to obtain 4.5 g of 2-t-butyl-5-chloro-4-methyl-3(2H)-pyridazinone.

Workup

  1. additionwas added
  2. temperatureThe resulting solution was heated at 60° to 70° C.
  3. additionAfter dropwise addition
  4. customthe resulting mixture was subjected to reaction at room temperature for 1.5 hours
  5. customThe reaction liquid
  6. extractionextraction
  7. washThe resulting organic layer was washed with 500 ml of a 10% sodium hydroxide solution
  8. dry with materialwith 500 ml of water, and then dried over anhydrous sodium sulfate
  9. distillationSolvent was distilled off
  10. customunder reduced pressure to give 17.2 g of a crude product
  11. distillationThe crude product was subjected to distillation (boiling point: 60° to 62° C./0.22 mmHg)
  12. washto column chromatography [on silica gel; eluting with hexane-acetone (15:1)]
  13. customfor separation and purification

Sources & evidence

ORD record
ord-b83cf91ca9824803aa21abadcb549e29
Source dataset
uspto-grants-1989_06
Patent number
US04837217

Reaction notes

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