Acetic Anhydride → 2-Methylthiazolo[4,5-c]quinoline

HRID 2305437Notes

Reaction equation

HRID 2305437 reaction equation
[NH2:1][C:2]1[CH:3]=[N:4][C:5]2[C:10]([C:11]=1[SH:12])=[CH:9][CH:8]=[CH:7][CH:6]=2.[C:13](OC(=O)C)(=O)[CH3:14]>C(O)(=O)C>[CH3:13][C:14]1[S:12][C:11]2[C:10]3[CH:9]=[CH:8][CH:7]=[CH:6][C:5]=3[N:4]=[CH:3][C:2]=2[N:1]=1

Participants

4

Reactant 2

HCID 7918Acetic AnhydrideHCID 1785079903-Aminoquinoline-4-thiol

Product 1

HCID 30661292-Methylthiazolo[4,5-c]quinoline

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Procedure

A suspension of 3-aminoquinoline-4-thiol (about 12 g) in a mixture of acetic anhydride (150 mL) and acetic acid (300 mL) was heated at reflux overnight. The reaction mixture was filtered to remove a fine solid. The filtrate was evaporated under vacuum. The residue was diluted with ethanol then refluxed for 30 minutes. The solution was concentrated under vacuum and the residue diluted with water. The aqueous residue was made basic with sodium hydroxide and then extracted with diethyl ether. The ether extracts were combined, dried over magnesium sulfate and filtered. The filtrate was evaporated to provide 12.8 g of crude product. A sample (800 mg) was recrystallized from hexane to provide 2-methylthiazolo[4,5-c]quinoline as yellow needles, m.p. 95.5-97.5° C. Analysis: Calculated for C11H8N2S: %C, 65.97; %H, 4.03; %N, 13.99; Found: %C, 65.96; %H, 4.16; %N 14.08.

Workup

  1. temperaturewas heated
  2. temperatureat reflux overnight
  3. filtrationThe reaction mixture was filtered
  4. customto remove a fine solid
  5. customThe filtrate was evaporated under vacuum
  6. additionThe residue was diluted with ethanol
  7. temperaturethen refluxed for 30 minutes
  8. concentrationThe solution was concentrated under vacuum
  9. additionthe residue diluted with water
  10. extractionextracted with diethyl ether
  11. dry with materialdried over magnesium sulfate
  12. filtrationfiltered
  13. customThe filtrate was evaporated
  14. customto provide 12.8 g of crude product
  15. customA sample (800 mg) was recrystallized from hexane

Sources & evidence

ORD record
ord-f3a3a72f8aa0473ea5c0d42d80523565
Source dataset
uspto-grants-2002_08
Patent number
US06440992B1

Reaction notes

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