| 摘要 |
<p>Disclosed herein is an improvement in a method for making compounds having the structural formulae (I) or (II) wherein: X is a) phenyl; lower phenylalkoxy, phenoxy; or benzyl; or b) one subtituent from group a) and one or more substituents selected from C1-C4 alkoxy; hydroxyl; halogen; lower alkyl; and lower alkylthio; or c) along with the phenyl to which it is attached, forms a multiple fused ring heterocycle such as dibenzofuranyl; Y is H, C1-C4 alkanoyl, C1-C4 haloalkanoyl, dialkoxyphosphoryl, alkylaminocarbonyl, haloalkylsulfonyl, or C1-C4 alkoxy carbonyl; and R is H, C1-C6 alkyl, C1-C6 alkoxy, C3-C6 cycloalkoxy, haloalkyl, alkoxyalkyl, arylalkoxy, alkenyl, alkylthio, alkoxycarbonyl, alkylamino, heteroaryl, arylalkyl, haloalkoxy, aryloxy, or C3-C6 cycloalkyl; and Z is O or S, wherein the improvement comprises the steps of: A) selecting as a starting material a compound of structural formula (III); B) dissolving compound III in an organic solvent selected from the group consisting of methyl t-butyl ether, ethylene glycol dimethyl ether, 2-methoxyethyl ether, acetonitrile, and acetic acid, and C) nitrating with nitric acid to form a compound of structural formula (IV).</p> |
