Ethyl benzoylacetate → ethyl 2-bromo-3-oxo-3-phenylpropanoate

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Reaction Steps

To a stirred solution of benzoylacetic acid, ethyl ester (0.01 mol) in a solvent such as, for example, chloroform is added N-bromosuccinimide (NBS, 0.01 mol), and the mixture is stirred. Reaction progress may be followed by TLC or HPLC. When a sufficient amount of benzoyl-bromoacetic acid, ethyl ester is formed, ethyl acetate is added, and the mixture is rotary evaporated to remove chloroform. To the resulting ethyl acetate mixture is added thiocarbamic acid, benzyl ester, which may be prepared as described in Step (a) above, and a suitable non-nucleophilic base such as those described in Example 17 above, and the mixture is stirred. Reaction progress may be followed by TLC or HPLC. When a sufficient amount of the desired product is formed, the reaction is washed with 0.01 M hydrochloric acid, water, brine, and dried over sodium sulfate. The mixture is rotary evaporated to give 2-benzyloxy-4-phenyl-thiazol-5-carboxylic acid, ethyl ester, which may be purified, if needed or desired, by chromatography on silica gel or crystallization.

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