Sulfuric Acid → HCID 21873921, compound

HRID 723395Notes

Reaction equation

HRID 723395 reaction equation
[C:1]([C:4]1[CH:9]=[CH:8][N:7]2[C:10]([CH3:14])=[C:11]([CH3:13])[N:12]=[C:6]2[C:5]=1[NH:15]C(=O)C(C)(C)C)(=[O:3])[CH3:2].S(=O)(=O)(O)O.C(Cl)Cl.[OH-].[Na+]>CO>[C:1]([C:4]1[CH:9]=[CH:8][N:7]2[C:10]([CH3:14])=[C:11]([CH3:13])[N:12]=[C:6]2[C:5]=1[NH2:15])(=[O:3])[CH3:2]

Participants

6

Reactant 4

HCID 1118Sulfuric AcidHCID 6344DichloromethaneHCID 14798Sodium HydroxideHCID 21873934HCID 21873934, compound

Product 1

HCID 21873921HCID 21873921, compoundYield 39.6%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

A cooled solution of 80.4 g of 7-acetyl-2,3-dimethyl-8-pivaloylaminoimidazo[1,2-a]pyridine in 720 ml of methanol is treated with 496 ml of concentated sulfuric acid and heated at reflux for 2.5 hours. It is then poured onto 1 l of ice water, 400 ml of methylene chloride are added and the mixture is adjusted to pH 7 with 10 N sodium hydroxide solution with cooling. After phase separation, the aqueous phase is again extracted twice with 300 ml of methylene chloride each time, the organic phases are collectively washed with 1 l of water, dried over sodium sulfate and the solvent is stripped off in vacuo. The solid residue is purified on silica gel (eluent: ethyl acetate). 22.5 g of the title compound of m.p. 195–97° C. (diethyl ether) are obtained.

Workup

  1. temperatureheated
  2. temperatureat reflux for 2.5 hours
  3. additionare added
  4. temperaturewith cooling
  5. customAfter phase separation
  6. extractionthe aqueous phase is again extracted twice with 300 ml of methylene chloride each time
  7. washthe organic phases are collectively washed with 1 l of water
  8. dry with materialdried over sodium sulfate
  9. customThe solid residue is purified on silica gel (eluent: ethyl acetate)

Sources & evidence

ORD record
ord-51455382728d4281997a7e5596d36b62
Source dataset
uspto-grants-2006_11
Patent number
US07141567B2

Reaction notes

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