| 摘要 |
<p>3-Amino-4-hydroxybenzoic acids are prepared by: a) contacting a p-halobenzoic acid with nitric acid in an acidic reaction medium under conditions such that a 3-nitro-4-halobenzoic acid is prepared; (b) contacting the 3-nitro-4-halobenzoic acid with an alkali metal hydroxide in a reaction medium under conditions such that the halo moiety is replaced with a hydroxide moiety, to prepare a 3-nitro-4-hydroxybenzoic acid, or salt thereof; and (c) reducing the 3-nitro-4-hydroxybenzoic acid in a reaction medium under conditions such that a 4-hydroxy-3-aminobenzoic acid is prepared.</p> |
