Hydrochloric Acid → Ethyl 2-chlorothiazole-4-carboxylate

HRID 610994Notes

Reaction equation

HRID 610994 reaction equation
N(OC(C)(C)C)=O.N[C:9]1[S:10][CH:11]=[C:12]([C:14]([O:16][CH2:17][CH3:18])=[O:15])[N:13]=1.O.[ClH:20]>C(#N)C.[Cu](Cl)Cl.C(Cl)Cl>[Cl:20][C:9]1[S:10][CH:11]=[C:12]([C:14]([O:16][CH2:17][CH3:18])=[O:15])[N:13]=1

Participants

8

Reactant 4

HCID 313Hydrochloric AcidHCID 962WaterHCID 10906Tert-Butyl nitriteHCID 73216Ethyl 2-aminothiazole-4-carboxylate

Product 1

HCID 13106141Ethyl 2-chlorothiazole-4-carboxylate

Reagents, catalysts & solvents 3

HCID 24014Cupric ChlorideCatalystHCID 6342AcetonitrileSolventHCID 6344DichloromethaneSolvent

Conditions

Temperature
62.5 °C

Procedure

To a mixture of copper (II) chloride (20 g, 0.15 mol) and 90% t-butyl nitrite (24 mL, 0.18 mol) in 500 mL acetonitrile at 60° C. was added in portions ethyl 2-amino-4-thiazolecarboxylate (21 g, 0.12 mol), maintaining the temperature at between 60-65° C. After the addition, the resulting reaction mixture was heated at 80° C. for 1 h, then cooled to RT and poured into a mixture of water, CH2Cl2 and 25 mL conc HCl. The aq layer was separated and extracted with CH2Cl2. The combined organic layers were washed with water, brine, dried and concentrated to give 21.5 g of ethyl 2-chloro-4-thiazolecarboxylate.

Workup

  1. additionAfter the addition
  2. customthe resulting reaction mixture
  3. temperaturewas heated at 80° C. for 1 h
  4. temperaturecooled to RT
  5. customThe aq layer was separated
  6. extractionextracted with CH2Cl2
  7. washThe combined organic layers were washed with water, brine
  8. customdried
  9. concentrationconcentrated

Sources & evidence

ORD record
ord-a8dba9f9ae6b40298bba59bc8733f4e3
Source dataset
uspto-grants-1999_12
Patent number
US05998466

Reaction notes

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