1621401-12-4Relevant articles and documents
Directed lithiation of N′-[2-(4-methoxyphenyl)ethyl]-N, N-dimethylurea and tert-butyl [2-(4-methoxyphenyl)ethyl]carbamate
Smith, Keith,El-Hiti, Gamal A.,Alshammari, Mohammed B.
, p. 394 - 402 (2014/02/14)
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%). Georg Thieme Verlag KG Stuttgart · New York.