semicarbazone Chem.
(sɛmɪˈkɑːbəzəʊn)
[f. prec. + -one.]
Any of a class of (usu. crystalline) compounds of general formula RR{p}C:N·NH·CO·NH2 which are prepared by the condensation of semicarbazide with carbonyl compounds, in order to characterize the parent carbonyl or to protect the carbonyl group in synthesis.
| 1896 Jrnl. Chem. Soc. LXX. i. 343 Mesityl oxide semicarbazone melts at 156°. 1938 G. H. Richter Textbk. Org. Chem. vii. 102 The semicarbazones may be converted into hydrazones by the action of sodium ethylate. 1973 H. J. E. Loewenthal in J. F. W. McOmie Protective Groups in Org. Chem. ix. 340 In general, and in the steroid field in particular, ease of semicarbazone formation from different types of carbonyl groups follows the order observed with other protecting groups. |