Sodium Hydroxide → 6,7-Dihydro-4-methyl-2-(4-chlorophenyl)-4H-pyrano[4,3-d]thiazole-4-acetic acid

HRID 258581Notes

Reaction equation

HRID 258581 reaction equation
[CH3:1][C:2]1([CH2:18][C:19]([O:21]CC)=[O:20])[C:10]2[S:9][C:8]([C:11]3[CH:16]=[CH:15][C:14]([Cl:17])=[CH:13][CH:12]=3)=[N:7][C:6]=2[CH2:5][CH2:4][O:3]1.[OH-].[Na+]>CO>[CH3:1][C:2]1([CH2:18][C:19]([OH:21])=[O:20])[C:10]2[S:9][C:8]([C:11]3[CH:12]=[CH:13][C:14]([Cl:17])=[CH:15][CH:16]=3)=[N:7][C:6]=2[CH2:5][CH2:4][O:3]1

Participants

4

Reactant 2

HCID 14798Sodium HydroxideHCID 54049665ethyl 6,7-dihydro-4-methyl-2-(4-chlorphenyl)-4H-pyrano[4,3-d]thiazole-4-acetate

Product 1

HCID 124290066,7-Dihydro-4-methyl-2-(4-chlorophenyl)-4H-pyrano[4,3-d]thiazole-4-acetic acid

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

The latter ester is dissolved in methanol (500 ml) followed by the addition of sodium hydroxide (80 g) and the resulting mixture is heated at reflux temperature for 5 hr. The solvent is removed by distillation, water is added to the residue and the solution is extracted with ether. The aqueous basic phase is mixed with ether and the mixture is acidified with dilute hydrochloric acid. The organic phase is separated, washed with saturated sodium chloride solution, dried over sodium sulfate, and evaporated under reduced pressure. The residue is crystallized from chloroform-ether to give the title compound; mp 162°-164° C., γmaxCHCl3 2900 and 1705 cm-1.

Workup

  1. temperaturethe resulting mixture is heated
  2. temperatureat reflux temperature for 5 hr
  3. customThe solvent is removed by distillation, water
  4. additionis added to the residue
  5. extractionthe solution is extracted with ether
  6. additionThe aqueous basic phase is mixed with ether
  7. customThe organic phase is separated
  8. washwashed with saturated sodium chloride solution
  9. dry with materialdried over sodium sulfate
  10. customevaporated under reduced pressure
  11. customThe residue is crystallized from chloroform-ether

Sources & evidence

ORD record
ord-e090f359157a480ca1492a002bdf5f00
Source dataset
uspto-grants-1977_07
Patent number
US04033977

Reaction notes

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