89130-81-4Relevant articles and documents
NMR STUDIES ON IMIDINES. III. (1)H AND (13)C NUCLEAR MAGNETIC RESONANCE STUDY ON THE TAUTOMERISM AND GEOMETRICAL ISOMERISM OF 3-IMINOISOINDOLINONE AND SOME ALKYLATED DERIVATIVES. OBSERVATION OF E AND Z ISOMERS ABOUT A FREE IMINO GROUPING
Spiessens, Luc I.,Anteunis, Marc J. O.
, p. 965 - 994 (2007/10/02)
3-Iminoisoindolinone (1) and some N-alkyl derivatives (8, 9, 10, 11, 12, 16 and 17) have been fully examined by (1)H and (13)C NMR spectroscopy. 3-(Methylimino)isoindolinone (12) cannot be obtained by reaction of 1 with methylamine, because it rearranges to 3-imino-2-methylisoindolinone (11), which reacts further to 2-methyl-3-(methylimino)isoindolinone (10).Both compounds have been shown to adopt the E configuration predominantly (88 percent for 11 at -55 deg C (CDCl3); 100 percent for 10). 3-(Methylimino)isoindolinone (12) favours the Z configuration (96 percent). Analogous results are found for the butyl derivatives (16, 17). 3-Imino isoindolinone (1) is present as the imino tautomer for 70 percent in DMSO-d6 solution as established by comparison of (13)C NMR chemical shift values of 1 with those of model compounds, 3-imino-2-methyl isoindolinone (11) and 3-(dimethylamino)isoindolinone (8).The tautomeric equilibrium is more extreme towards the imino form for the N-methyl and N-butyl derivatives 12 and 16. 2,3,4,5-tetrahydroisoindolinopyrimidin-6-one served as the imino model compound together with 10. (1)H and(13)C NMR data are given for several phthalic acid derivatives.
