Carboxamides hydroxamic acid derivative

The carboxamide moiety was then examined, preparing several 2,4-dichlorophenoxy compounds in solution (9.37-9.43, Fig. 9.20). Replacement of the primary amide with small N-nucleophile-derived groups (9.41-9.43) maintained activity, as did the methyl ester-substituted 9.39 while the free acid 9.38, the deletion compiound 9.37, and more complex secondary amide analogues lost inhibitory activity. The hydroxamate function significantly increased the solubihty profile of 9.43 thus it was considered relevant for the optimization of the chemical series (Fig. 9.20). 

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