Oxazole → ethyl 2-amino-5-bromothiazole-4-carboxylate

HRID 1416317Notes

Reaction equation

HRID 1416317 reaction equation
[Br:1][CH2:2][C:3](=O)[C:4]([O:6][CH2:7][CH3:8])=[O:5].[NH2:10][C:11]([NH2:13])=[S:12].O1C=CN=C1.BrBr.C(=O)([O-])[O-].[Na+].[Na+]>Br>[NH2:13][C:11]1[S:12][C:2]([Br:1])=[C:3]([C:4]([O:6][CH2:7][CH3:8])=[O:5])[N:10]=1

Participants

7

Reactant 5

HCID 9255OxazoleHCID 10340Sodium CarbonateHCID 24408BromineHCID 66144Ethyl bromopyruvateHCID 2723790Thiourea

Product 1

HCID 1284665ethyl 2-amino-5-bromothiazole-4-carboxylate

Reagents, catalysts & solvents 1

HCID 260Hydrogen BromideSolvent

Conditions

Temperature
60 °C

Procedure

Ethyl 2-aminothiazoles-4-carboxylate (5.0 g) (prepared from ethyl bromopyruvate and thiourea by the procedure described in J. Med. Chem., 1971, 14, 1075 for the corresponding oxazole) in concentrated hydrobromic acid (9 cm3) was stirred at ambient temperature and treated dropwise with bromine (3.2 g), then heated to 60° C. for 2 hours, neutralised with sodium carbonate and the product extracted into ethyl acetate. The organic phase was dried (MgSO4) and evaporated under reduced pressure to give ethyl 2-amino-5-bromothiazole-4-carboxylate (1.54 g). MH+ =251; 1H NMR: δ 1.40(3H,t); 4.40(2H,t); 5.6(2H,br s).

Workup

  1. extractionthe product extracted into ethyl acetate
  2. dry with materialThe organic phase was dried (MgSO4)
  3. customevaporated under reduced pressure

Sources & evidence

ORD record
ord-4211cc4ef8b54040bf6d4e7669297bf4
Source dataset
uspto-grants-1999_06
Patent number
US05912243

Reaction notes

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