Sulfuric Acid → HCID 117903099, compound

HRID 1772174Notes

Reaction equation

HRID 1772174 reaction equation
[CH3:1][N:2]1[C:10]2[CH:9]=[C:8]([CH3:11])[N:7]=[C:6]([CH3:12])[C:5]=2[C:4](=[O:13])[N:3]1[CH3:14].C1C(=O)N([Br:22])C(=O)C1.OS(O)(=O)=O.[OH-].[Na+]>O>[Br:22][C:9]1[C:10]2[N:2]([CH3:1])[N:3]([CH3:14])[C:4](=[O:13])[C:5]=2[C:6]([CH3:12])=[N:7][C:8]=1[CH3:11]

Participants

6

Reactant 4

HCID 1118Sulfuric AcidHCID 14798Sodium HydroxideHCID 67184N-bromobutanimideHCID 117902845HCID 117902845, compound

Product 1

HCID 117903099HCID 117903099, compound

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

A mixture of 1,2,4,6-tetramethyl-1H,2H,3H-pyrazolo[4,3-c]pyridin-3-one (0.33 g, 1.7 mmol), NBS (0.34 g, 1.9 mmol) and conc. H2SO4 (8 ml) is stirred at RT for 18 h. The mixture is poured onto ice-water. The water phase is made basic with an aqueous solution of sodium hydroxide (1 mol/l) and extracted with DCM. The combined organic layers are dried over MgSO4 and concentrated in vacuo. 7-bromo-1,2,4,6-tetramethyl-1H,2H,3H-pyrazolo[4,3-c]pyridin-3-one is used without further purification. Yield: 0.37 g (80%). HPLC-MS: M+H=270/272; tR=0.77 min (METHOD—1).

Workup

  1. additionThe mixture is poured onto ice-water
  2. extractionextracted with DCM
  3. dry with materialThe combined organic layers are dried over MgSO4
  4. concentrationconcentrated in vacuo
  5. custom7-bromo-1,2,4,6-tetramethyl-1H,2H,3H-pyrazolo[4,3-c]pyridin-3-one is used without further purification

Sources & evidence

ORD record
ord-6def95589acf401fada3b08c21c9b10e
Source dataset
uspto-grants-2016_02
Patent number
US09249151B2

Reaction notes

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