Compounds Containing a N-CO-N or Related Group

Urea and Its Derivatives Rule C-972

972.1 - The compound HN=C(OH)-NH2 is named "isourea" and this name is used as a basis for naming derivatives, together with the locants 1, 2, and 3 as shown, when no other group is present that has priority for citation as principal group. When the position of the double bond is unknown, N, N', and O are used as locants.

Examples to Rule C-972.1




If the position of the double bond is uncertain, so that choice cannot be made between the last two structures, then the name is: O-Ethyl-N-phenylisourea.

972.2 - The radical NH=C(OH)-NH- is named "1-isoureido-", and NH2-C(OH)=N- is named "3-isoureido-". "Isoureido-", without a numerical prefix, denotes a radical in which the position of the double bond is not proved. These names are used as a basis for designation of derivatives in which another group is to be cited as principal group.

Example to Rule C-972.2


See Recommendations'93 Table 31(a)

Compounds Containing a N-CO-N or Related Group C-973, C-974, C-975
Compounds Containing a N-CO-N-N or More Complex Group C-981, C-982, C-983, C-984, C-985


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