Use of 11C as a tracer for studying the synthesis of [11C]urea from [11C]cyanide |
| |
| Authors: | T E Boothe A M Emran R D Finn M M Vora P J Kothari |
| |
| Affiliation: | 1. High Energy Accelerator Research Organization, 1-1 Oho, Tsukuba, Ibaraki, 305-0801, Japan;2. Yokohama National University, 79-1 Tokiwadai, Hodogaya-ku, Yokohama, 240-8501, Japan;3. NASA Ames Research Center, Moffett Field, CA, 94035-1000, USA;1. International Research Centre, Centre for Supramoleular Chemistry, Department of Chemistry, Kalasalingam University (KARE), Anand Nagar, Krishnankoil, Srivilliputtur, Tamil Nadu 626 126, India;2. Department of Chemistry, J.P. College of Arts & Science, Agarakattu, Ayikudi, Tamil Nadu 627852, India;3. Department of Chemistry, Karunya University, Karunya Nagar, Coimbatore, Tamil Nadu 641114, India |
| |
| Abstract: | The use of reversed-phase liquid chromatography and radiochemical detection with carbon-11 (t1/2 = 20.4 min) as a tracer allowed the study of the preparation of [11C]urea from [11C]cyanide at no-carrier-added concentrations. [11C]cyanate was readily prepared by permanganate oxidation of [11C]cyanide at 75 degrees C. The conversion of NH4O11CN (approximately 0.03 mM) to [11C]urea in the presence of excess ammonium ions (0.28 M) was found to best fit pseudo first order reaction kinetics with a rate constant of 0.065 +/- 0.008 min-1 at 75 degrees C. Heating at higher temperatures (180-200 degrees C) revealed that the conversion of NH4O11CN to [11C]urea occurred in high yield in less than 3 min. The hydrolysis of [11C]cyanate to [11C]carbonate, a possible side reaction, was found to proceed at a rate of 0.010 +/- 0.001 min-1 at 113 degrees C. |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
