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Synthesis of 15N-labelled urea and methylenediurea

✍ Scribed by Thomas P. Murray; Ernest R. Austin; Robert G. Howard; G. T. Jones

Publisher
John Wiley and Sons
Year
1985
Tongue
French
Weight
398 KB
Volume
22
Category
Article
ISSN
0022-2135

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✦ Synopsis

A new technique was developed for the large-scale synthesis of lSN-labelled urea at low enrichment levels. The synthesis is based on nucleophilic displacement of the phenoxide ion from phenyl carbonate and uses anhydrouli Pmmonia as the nucleophile. In previous reports a copper catalyst was used; hovever, in this study it was found that the copper resulted in pmduct decompadtion and tar formation, which makes product purification difficult. A novel set of -tioh conditions was developed: no catalyst was used, and no pmduct decomposition or tar formation occurred. The reaction product was easily purified, and consistently high yields of 15N-labelled urea were obtained. lSN-labelled methylenediurea was prepared by the dilute solution reaction of formalin with ISN-labelled urea. The methodology developed for the reclamation of unreacted urea resulted in minimum loss of labelled urea.

High performance liquid chromatography has been used to determkC the chemical purity of both urea and methylenediurea.

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