Hydrochloric Acid → Ethyl 2-amino-5-(2-pyridinecarbonyl)-4-thiazolecarboxylate

HRID 648567Notes

Reaction equation

HRID 648567 reaction equation
[NH2:1][C:2]([NH2:4])=[S:3].C([O-])(=O)C.[Na+].Cl.Cl[CH:12]([C:20]([C:22]1[CH:27]=[CH:26][CH:25]=[CH:24][N:23]=1)=[O:21])[C:13](=O)[C:14]([O:16][CH2:17][CH3:18])=[O:15].Cl>O1CCCC1.O>[NH2:1][C:2]1[S:3][C:12]([C:20]([C:22]2[CH:27]=[CH:26][CH:25]=[CH:24][N:23]=2)=[O:21])=[C:13]([C:14]([O:16][CH2:17][CH3:18])=[O:15])[N:4]=1

Participants

7

Reactant 4

HCID 313Hydrochloric AcidHCID 517045Sodium AcetateHCID 2723790ThioureaHCID 20144948Ethyl 3-chloro-4-(2-pyridyl)-2,4-dioxo-butyrate hydrochloride

Product 1

HCID 20145044Ethyl 2-amino-5-(2-pyridinecarbonyl)-4-thiazolecarboxylateYield 20.7%

Reagents, catalysts & solvents 2

HCID 962WaterSolvent2×HCID 8028TetrahydrofuranSolvent

Procedure

To a solution of thiourea (4.5 g) and sodium acetate (5 g) in a mixture of tetrahydrofuran (50 ml) and water (15 ml) was added ethyl 3-chloro-4-(2-pyridyl)-2,4-dioxo-butyrate hydrochloride (5.6 g). After the mixture was stirred at 45° C. to 50° C. for 2 hours, water (50 ml) was added thereto. The resulting mixtures was acidified to pH 1.0 with 10% hydrochloric acid. The precipitate was collected by filtration. The precipitate was added to a mixture of water and ethyl acetate, and adjusted to pH 6.0 with 10% potassium carbonate. The separated ethyl acetate layer was washed with brine, dried over magnesium sulfate, and evaporated in vacuo. The residue was recrystallized from a mixture of ethyl acetate and tetrahydrofuran to give ethyl 2-amino-5-(2-pyridinecarbonyl)-4-thiazolecarboxylate (1.1 g).

Workup

  1. filtrationThe precipitate was collected by filtration
  2. additionThe precipitate was added to a mixture of water and ethyl acetate
  3. washThe separated ethyl acetate layer was washed with brine
  4. dry with materialdried over magnesium sulfate
  5. customevaporated in vacuo
  6. customThe residue was recrystallized from a mixture of ethyl acetate and tetrahydrofuran

Sources & evidence

ORD record
ord-1e5ee50e2c5b46098b2e1f80f7594485
Source dataset
uspto-grants-1988_04
Patent number
US04735957

Reaction notes

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