Abstract

N′-[2-(4-Methoxyphenyl)ethyl]-N,N-dimethylurea and tert-butyl [2-(4-methoxyphenyl)ethyl]carbamate are doubly lithiated on the nitrogen and ortho to the directing metalating group at –20 to 0 °C with three mole equivalents of n-BuLi in anhydrous THF. Reactions of the dilithium reagents produced in situ with various electrophiles give high yields of the corresponding substituted products. In the case of the urea, side-products due to lithiation and substitution on one of the methyl groups of the urea unit are obtained in low yields (0–17%).

N′-[2-(4-Methoxyphenyl)ethyl]-N,N-dimethylurea and tert-butyl [2-(4-methoxyphenyl)ethyl]carbamate are doubly lithiated on the nitrogen and ortho to the directing metalating group at –20 to 0 °C with three mole equivalents of n-BuLi in anhydrous THF. Reactions of the dilithium reagents produced in situ with various electrophiles give high yields of the corresponding substituted products. In the case of the urea, side-products due to lithiation and substitution on one of the methyl groups of the urea unit are obtained in low yields (0–17%).

中文翻译：

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N'-[2-（4-甲氧基苯基）乙基] -N，N-二甲基脲和叔丁基[2-（4-甲氧基苯基）乙基]氨基甲酸酯的直接锂化

摘要

N '-[2-（4-甲氧基苯基）乙基] -N，N-二甲基脲和叔丁基[2-（4-甲氧基苯基）乙基]氨基甲酸酯在氮上双锂化，并在–20处与定向金属化基团邻位在无水THF中用三摩尔当量的n- BuLi加热至0°C 。原位产生的二锂试剂与各种亲电试剂的反应可得到相应取代产物的高产率。在尿素的情况下，由于尿素单元的一个甲基上的锂化和取代而产生的副产物收率很低（0-17％）。

N '-[2-（4-甲氧基苯基）乙基] -N，N-二甲基脲和叔丁基[2-（4-甲氧基苯基）乙基]氨基甲酸酯在氮上双锂化，并在–20处与定向金属化基团邻位在无水THF中用三摩尔当量的n- BuLi加热至0°C 。原位产生的二锂试剂与各种亲电试剂的反应可得到相应取代产物的高产率。在尿素的情况下，由于尿素单元的一个甲基上的锂化和取代而产生的副产物收率很低（0-17％）。