摘要 |
The invention provides novel non-toxic biodegradable derivatives of the formula: <IMAGE> I wherein Ra is (1-12C)alkyl, phenyl, naphthylmethyl or cinnamyl, the aromatic rings of which optionally bear one or two halogeno substituents, or Ra is benzyl optionally bearing up to 3 substituents independently selected from halogeno, trifluoromethyl, (1-4C)alkyl, (1-4C)alkoxy, nitro, cyano and hydroxy; Rb and Rc are independently selected from hydrogen and non-toxic biodegradable protecting radicals, but are not both hydrogen; and benzene ring A optionally bears one substituent selected from halogeno, (1-4C)alkyl, (1-4C)alkoxy, nitro and hydroxy, or bears two substituents independently selected from halogeno, (1-4C)alkyl and nitro; pharmaceutical compositions thereof; and processes for their manufacture. The amides of formula I in which Rb=Rc=H are potent inhibitors of the enzyme aldose reductase. The derivatives of formula I provided by the invention are of use in vivo in the treatment or prophylaxis of certain complications of diabetes or galactosemia.
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