Synthesis and Application of Isocyanates Radiolabeled with Carbon-11
作者:Alan A. Wilson、Armando Garcia、Sylvain Houle、Oleg Sadovski、Neil Vasdev
DOI:10.1002/chem.201002345
日期:2011.1.3
efficiently prepared by dehydration of [11C]carbamate salts, which in turn are easily formed from cyclotron‐produced [11C]CO2 and amines in the presence of a CO2 fixation agent. The [11C]isocyanates are useful radiosynthons for the synthesis of a variety of [carbonyl‐11C]‐labeled asymmetrical ureas and carbamate esters. The method is well suited to incorporate any isotope of carbon, and is especially
Lithiation and Substitution of N′-(ω-Phenylalkyl)-N,N-dimethylureas
作者:Keith Smith、Gamal El-Hiti、Mohammed Alshammari
DOI:10.1055/s-0031-1291008
日期:2012.7
give the corresponding substituted derivatives in excellent yields. Lithiation of N′-(3-phenylpropyl)-N,N-dimethylurea takes place on the α-CH2 with tert-butyllithium at 0 °C. On the other hand, lithiation of N′-(4-phenylbutyl)-N,N-dimethylurea with tert-butyllithium at 0 °C takes place on one of the methyl groups of the urea unit. Lithiation of N′-phenethyl-N,N-dimethylurea with three equivalents