作者:Iaroslav BAGLAI、Valérie MARAVAL、Zoia Vsevolodivna VOITENKO、Carine DUHAYON、Yulian Mikhailovich VOLOVENKO、Remi CHAUVIN
DOI:10.3906/kim-1306-58
日期:——
C-, N-, and/or O-methylation products were generated from 11H-isoindolo[2,1-a]quinazoline-5-one upon treatment with NaH followed by iodomethane under air, and possible recrystallization from methanol. Two products were fully characterized by NMR and X-ray diffraction analysis. In accordance with the HSAB principle, this soft methylating agent (MeI) leads mainly to the C,C-dimethylated product 11,11-dimethyl-11H-isoindolo[2,1-a]quinazoline-5-one, which was previously not observed, beside the N-methylated product, in a procedure using methyl tosylate as a hard methylating agent of the same substrate in the initial absence of a base. A mechanism is finally proposed for the formation of methyl 2-(3-methyl-4-oxo-3,4-dihydroquinazolin-2-yl)benzoate as an oxidation side product.
11H-isoindolo[2,1-a]quinazoline-5-one 经 NaH 处理后,在空气中加入碘甲烷,并可能从甲醇中重结晶,生成 C-、N- 和/或 O-甲基化产物。核磁共振和 X 射线衍射分析对两种产品进行了全面鉴定。根据 HSAB 原理,这种软甲酯化剂(MeI)主要产生 C,C-二甲基产物 11,11-二甲基-11H-异吲哚并[2,1-a]喹唑啉-5-酮,而在使用甲基对甲苯磺酸酯作为硬甲酯化剂处理相同底物时,在最初没有碱的情况下,除了 N-甲基化产物外,以前没有观察到这种产物。最后提出了 2-(3-甲基-4-氧代-3,4-二氢喹唑啉-2-基)苯甲酸甲酯作为氧化副产物的形成机理。