| 摘要 |
<p>A method for the preparation of a group of variously substituted ureas is disclosed, these compounds being obtained by the pyrolytic decomposition of the alkali metal or alkaline earth metal carbamates corresponding to the expected ureas, the reaction taking place at a temperature of between 150 DEG and 400 DEG C under atmospherical pressures, and preferably under subatmospherical pressures, under which conditions the expected urea either sublimes or is distilled.</p> |
