Bromine → 2-Bromo-1,4-dimethoxynaphthalene

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Reaction Steps

The process of preparing the novel compounds of this invention comprises the steps of (1) brominating 1,4-dimethoxynaphthalene with liquid bromine in an organic solvent such as acetic acid at room temperature to form the 2-bromo-1,4-dimethoxynaphthalene, (2) converting the bromine derivative to the carboxylic acid derivative by lithiation and carboxylation. The lithiation is conducted in a known procedure, as for example, by treating the bromo derivative with n-Butyllithium in an organic solvent under anhydrous conditions at a low temperature, such as -78° C. The resulting lithium compound is not isolated, but converted into the carboxylic acid by adding dry ice to the cooled lithium compound and allowing the reaction mixture to come to room temperature. (3) The carboxylic acid derivative is then converted to the acid chloride by treating with thionyl chloride at room temperature. (4) The resulting acid chloride is condensed with the appropriate amine to form the carboxamide. The condensation reaction is carried out by treating the acid chloride in an organic solvent with the appropriate amine at room temperature in the presence of a proton acceptor.

Provenance & Evidence