| 摘要 |
<p>A process for the preparation of cyclic urea derivatives of the formula <IMAGE> (I) in which R1 and R2 are equal or different and represent hydrogen, alkyl having from 1 to 6 carbon atoms or alkoxy having from 1 to 3 carbon atoms, which comprises reacting a 1,2-diaminobenzene of the formula <IMAGE> (II) in which R1 and R2 have the meaning indicated above are reacted with carbon dioxide in the presence of water under superatmospheric pressure at a temperature of at least 120 DEG C.</p> |
