| 摘要 |
A process for prepg. 2-acyl-3,4-dialkoxyaniline of formula (I) comprises (a) reacting 3,4-dialkoxyaniline with pivaloyl halide to provide 3',4'-dialkoxy-2,2-dialkylpropioanilide, (b) reacting with org. lithium i.e. n-butyl lithium to prep. dilithio intermediate, (c) reacting with CO2 to obtain 2'-carboxy-3',4'dialkoxy-2,2- dialkylpropioanilide in THF, dioxane, (d) reacting with acid anhydride i.e. acetic acid anhydride to give 2-alkyl5,6-dialkoxy-1,3- benzoxazin-4-on, (e) reacting with org. metal reagent i.e. alkyl-Mg- halide to produce 2'-acyl-3',4'-dialkoxy2,2-dialkylpropioanilide, and (f) acid-hydrolysing. In (I), R1, R2 and R3 are each lower alkyl.
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