Directed Lithiation of N'-(2-(4-Methoxyphenyl)ethyl)-N,N-dimethylurea and tert-Butyl (2-(4-Methoxyphenyl)ethyl)carbamate

Journal Article

Alshammari, Mohammed B. . 2014

• Publication Work Type: Research
• Publication Online URL: https://www.thieme-connect.de/ejournals/pdf/10.../s-0033-1338570.pd
• Magazine \ Newspaper: Synthesis
• Issue Number: 3
• Volume Number: 46
• Pages: 394-402

Publication 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%).