Sulfuric Acid → Ethyl 2-bromo-1,3-thiazole-4-carboxylate

HRID 992998Notes

Reaction equation

HRID 992998 reaction equation
S(=O)(=O)(O)O.N[C:7]1[S:8][CH:9]=[C:10]([C:12]([O:14][CH2:15][CH3:16])=[O:13])[N:11]=1.[Br-:17].[Na+].N([O-])=O.[Na+]>S([O-])([O-])(=O)=O.[Cu+2].CCOCC>[Br:17][C:7]1[S:8][CH:9]=[C:10]([C:12]([O:14][CH2:15][CH3:16])=[O:13])[N:11]=1

Participants

7

Reactant 4

HCID 1118Sulfuric AcidHCID 73216Ethyl 2-aminothiazole-4-carboxylateHCID 253881Sodium BromideHCID 23668193Sodium Nitrite

Product 1

HCID 353965Ethyl 2-bromo-1,3-thiazole-4-carboxylate

Reagents, catalysts & solvents 2

HCID 24462Copper SulfateCatalystHCID 3283Diethyl EtherSolvent

Procedure

To a sulfuric acid solution (120 mL) of ethyl 2-aminothiazole-4-carboxylate (7.47 g), copper sulfate (10.91 g) and sodium bromide (8.12 g), a solution of sodium nitrite (3.63 g) in ice water was added dropwise over 15 minutes under ice cooling. The resultant mixture was stirred for 30 minutes and for 2 hours at room temperature. Ether was added to the reaction mixture, and the mixture was washed with water. The resultant water layer was neutralized with sodium hydroxide and extracted with ether. The extract was combined with the previously separated ether layer, washed with saturated brine and dried over anhydrous sodium sulfate. After concentrating the combined ether layer under reduced pressure, the resultant residue was purified by column chromatography on silica gel (chloroform), and the resultant crude crystals were recrystallized from hexane to obtain the title compound.

Workup

  1. washthe mixture was washed with water
  2. extractionextracted with ether
  3. washwashed with saturated brine
  4. dry with materialdried over anhydrous sodium sulfate
  5. concentrationAfter concentrating the combined ether layer under reduced pressure
  6. customthe resultant residue was purified by column chromatography on silica gel (chloroform)
  7. customthe resultant crude crystals were recrystallized from hexane

Sources & evidence

ORD record
ord-887f9d21416e4ab3bdcd041601bb7fd2
Source dataset
uspto-grants-2002_10
Patent number
US06472386B1

Reaction notes

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