85865-57-2Relevant academic research and scientific papers
Studies of the New Herbicide KIH-6127. Part I. Novel Synthesis of Methyl 6-Acetylsalicylate as a Key Synthetic Intermediate for the Preparation of 6-Acetyl Pyrimidin-2-yl Salicylates and Analogues
Tamaru, Masatoshi,Saito, Yoshihiro
, p. 125 - 130 (2007/10/03)
A novel synthesis of methyl 6-acetylsalicylate as a key synthetic intermediate for methyl 2-[(4,6-dimethoxypyrimidin-2-yl)oxy]-6-[1-(methoxyimino)ethyl]benzoate (KIH-6127) was studied, and directed at 6-substituted pyrimidin-2-yl salicylate herbicides and their analogues. Three synthetic approaches were successful: a modification of the Sandmeyer reaction of 6-acetylanthranilate (Method A), a direct ring-opening reaction of 3-methylphthalide using potassium permanganate, and magnesium nitrate (Method B), and a regioselective ortholithiation of the protected 3-hydroxyacetophenone (Method C). These methods were applicable for the synthesis of various 6-acyl salicylates.
Arene-Metal Complex in Organic Synthesis: Directed Regioselective Lithiation of (?-Substituted benzene)chromium Tricarbonyl Complexes
Uemura, Motokazu,Nishikawa, Naomi,Take, Kazuhiko,Ohnishi, Masato,Hirotsu, Ken,et al.
, p. 2349 - 2356 (2007/10/02)
(3-Methoxybenzyl alcohol)chromium tricarbonyl complex (8) and (2-substituted 7-methoxy-1-tetralol)chromium complexes 14-17 are selectively lithiated at the 4-position and 6-position, respectively, by treatment with n-BuLi/TMEDA.The regioselectivity of this lithiation is improved with increasing bulk of the butyllithium reagent employed.Since the direct lithiation of the corresponding chromium-free arenes normally proceeds at the 2- and 8-positions, complementarily substituted arenes can be prepared by using chromium tricarbonyl complexes.The different lithiation is explained by the relative configuration of the chromium tricarbonyl group in the (?-arene)Cr(CO)3 complexes and the electrostatic factor.This rationalization is supported, at least in part, by X-ray crystallography of the complex 16.On the other hand, the chromium complexes of arenes without a free hydroxyl group, such as benzyl methyl ether or ethylene acetals of benzaldehydes, are lithiated at the 2-position preferentially.
