semidinen.
/ˈsɛmɪdiːn/ Chemistry.
Any compound which is either (a) an ortho- anilino-derivative, or (b) an N-para-aminophenyl derivative, of a para-substituted aniline (distinguished as ortho- and para-semidines respectively); also semidine base; semidine reaction, semindine transformation, etc., the rearrangement of para-substituted hydrazobenzenes in the presence of acid to yield ortho- and para-semidines (in proportions governed by the nature of the substituents).
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the world > matter > chemistry > organic chemistry > chemical processes or reactions > [noun] > miscellaneous other
biuret reaction1883
condensation1886
semidine reaction1893
pinacol rearrangement1920
formylation1930
hydrogenolysis1931
polyamidation1946
ene reaction1969
1893 Jrnl. Chem. Soc. 64 i. 330 The hydrazo~compound..undergoes molecular change yielding two compounds, derivatives of ortho- and of para-amido~diphenylamine. It is proposed to call this reaction the semidine reaction, and to designate the orthamido~diphenylamine bases thus obtained by the name orthosemidines; the paramidodiphenylamine bases by the name parasemidines.
1898 Jrnl. Chem. Soc. 74 i. 441 Only 50 per cent. of the total semidines obtained.
1905 G. F. Goodchild & C. F. Tweney Technol. & Sci. Dict. s.v. Semidine Transformation These compounds are called Semidines: the first is an orthosemidine and the second a parasemidine, and the reaction is known as the semidine transformation. With methylparaethoxyazobenzene the course taken by the semidine transformation depends on the position of the methyl group.
1938 A. J. Mee tr. P. Karrer Org. Chem. xxxiv. 498 If a para-position in hydrazobenzene is already occupied by a substituent, there are still further possibilities of isomerization. In addition to a diphenyline base and benzidine compounds.., two diphenylamine derivatives are formed in which only one of the benzene nuclei has rotated, the so-called p-semidine and o- semidine bases. The transformation is known as the semidine transformation.
1959 E. S. Gould Mechanism & Struct. Org. Chem. xv. 658 The rearrangements of hydrazobenzenes to benzidines, to diphenylenes, and to o- semidines are third-order reactions, first order in substrate and second order in hydrogen ion.
1975 R. F. Brown Org. Chem. xxii. 772 A small amount of o shift occurs anyway, as well as a halfway shift to give semidines.
This entry has not yet been fully updated (first published 1933; most recently modified version published online June 2018).
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