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

Participants

Reaction Conditions

Reaction Steps

Ethyl 2-aminothiazole-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).

Provenance & Evidence