Ethyl 2-(cyclopentanecarboxamido)-3-mercaptopropanoate → Ethyl 2-cyclopentyl-4,5-dihydrothiazole-4-carboxylate

HRID 471123Notes

Reaction equation

HRID 471123 reaction equation
[CH:1]1([C:6]([NH:8][CH:9]([CH2:15][SH:16])[C:10]([O:12][CH2:13][CH3:14])=[O:11])=O)[CH2:5][CH2:4][CH2:3][CH2:2]1>C1(C)C=CC=CC=1>[CH:1]1([C:6]2[S:16][CH2:15][CH:9]([C:10]([O:12][CH2:13][CH3:14])=[O:11])[N:8]=2)[CH2:5][CH2:4][CH2:3][CH2:2]1

Participants

3

Reactant 1

HCID 57989260Ethyl 2-(cyclopentanecarboxamido)-3-mercaptopropanoate

Product 1

HCID 57989100Ethyl 2-cyclopentyl-4,5-dihydrothiazole-4-carboxylate

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

Tosic acid monohydrate (0.78 g) was added to a solution of ethyl 2-(cyclopentanecarboxamido)-3-mercaptopropanoate (example 59, step a) (5 g) in toluene (40 mL). The resulting mixture was heated at reflux under Dean and Stark conditions for 6 h. The reaction was allowed to cool, then the toluene solution was washed with saturated sodium bicarbonate solution (20 mL) and the solvent evaporated. The residue was azeotroped with toluene. The resulting white solid was purified by silica gel chromatography eluting with 9:1 isohexane:ethyl acetate. The fractions containing product were combined and evaporated to give the subtitled compound as a clear oil. Yield 3.2 g.

Workup

  1. temperatureThe resulting mixture was heated
  2. temperatureat reflux under Dean and Stark conditions for 6 h
  3. temperatureto cool
  4. washthe toluene solution was washed with saturated sodium bicarbonate solution (20 mL)
  5. customthe solvent evaporated
  6. customThe residue was azeotroped with toluene
  7. customThe resulting white solid was purified by silica gel chromatography
  8. washeluting with 9:1 isohexane
  9. additionThe fractions containing product
  10. customevaporated

Sources & evidence

ORD record
ord-a792d1ca103e4d8484d4d15cddccff86
Source dataset
uspto-grants-2014_01
Patent number
US08629271B2

Reaction notes

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