Ethanol → Ethyl 2-(2-thioxo-2,3-dihydrobenzoxazol-5-yl)propionate

HRID 2398755Notes

Reaction equation

HRID 2398755 reaction equation
[NH2:1][C:2]1[CH:3]=[C:4]([CH:9]([CH3:15])[C:10]([O:12][CH2:13][CH3:14])=[O:11])[CH:5]=[CH:6][C:7]=1[OH:8].C(O[C:19]([S-])=[S:20])C.[K+].C(O)C>O>[S:20]=[C:19]1[NH:1][C:2]2[CH:3]=[C:4]([CH:9]([CH3:15])[C:10]([O:12][CH2:13][CH3:14])=[O:11])[CH:5]=[CH:6][C:7]=2[O:8]1

Participants

5

Reactant 3

HCID 702EthanolHCID 2735045Potassium ethylxanthateHCID 12202638Ethyl 3-amino-4-hydroxy-phenyl-propionate

Product 1

HCID 20319623Ethyl 2-(2-thioxo-2,3-dihydrobenzoxazol-5-yl)propionate

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

A stirred mixture of ethyl 2-(3-amino-4-hydroxyphenyl)propionate (8.4 g.), potassium ethylxanthate (6.33 g.), ethanol (38 ml.) and water (6.5 ml.) was heated under reflux for 4 hours. The solution was evaporated to half volume and diluted with water (65 ml.). The mixture was acidified with 2N-hydrochloric acid and extracted several times with ether. The ethereal solution was washed with water, then dried with anhydrous sodium sulphate, and evaporated to give ethyl 2-(2-thioxo-2,3-dihydrobenzoxazol-5-yl)propionate as an oil. Dry chlorine was passed into a solution of the thione (9 g.) in freshly dried and distilled chloroform (150 ml.) with stirring for 4 hours. The solution was then washed with water, N-sodium hydroxide solution, then water (3x). The dried (Na2SO4) organic solution was evaporated to yield ethyl 2-(2-chloro-5-benzoxazolyl)propionate as a brown oil which was shown to be a single compound by thin layer chromatography.

Workup

  1. temperaturewas heated
  2. temperatureunder reflux for 4 hours
  3. customThe solution was evaporated to half volume
  4. additiondiluted with water (65 ml.)
  5. extractionextracted several times with ether
  6. washThe ethereal solution was washed with water
  7. dry with materialdried with anhydrous sodium sulphate
  8. customevaporated

Sources & evidence

ORD record
ord-1e2d7341631b4b839569e65bb8344a18
Source dataset
uspto-grants-1977_05
Patent number
US04025637

Reaction notes

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