| 摘要 |
NEW MATERIAL:The 4-substituted nirobenzoxazine derivative of formula I (R<1> is alkyl, alkenyl, alkynyl, alkoxyalkyl or alkoxyalkoxyalkyl; R<2> is H or CH3). EXAMPLE:7-Fluoro-6-nitro-4-propargyl-2H-1,4-benzoxazin-3(4H)-one. USE:Intermediate of herbicide. PREPARATION:The compound of formula I can be prepared by reacting the compound of formula II with the compound of formula R<1>-X (X is Cl, Br ir I). The compound of formula I can be converted to the compound of formula III useful as a herbicide by reacting with 3,4,5,6-tetrahydrophthalic anhydride after reduction. The starting compound of formula II can be produced by reducing and cyclizing the compound of formula IV (R<3> is lower alkyl) with iron powder, and selectively nitrating the resultant compound of formula V with a mixture of sulfuric acid and nitric acid.
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