The n.m.r. spectra of the four geometrical isomers of β-aminoenones, trans-s-trans, trans-s-cis, cis-s-trans, and cis-s-cis, are discussed. It was found that the chemical shift of the α-proton of β-aminoenones depends on both anisotropic effects and the electron density: δ=δ0–Δδstruc=ΔδAr+K(q–q0). Thus the conformation of non-rigid β-aminoenones can be determined from the observed and the calculated
we have prepared some new isoluminol, 7-(N,N-dialkylamino)-5-methyl-2,3-dihydrophthalazine-1,4-diones by means of a novel procedure involving the cycloaddition of dienamines to maleic acid derivatives. These compounds are characterized by the presence of a methyl group at C-5 and give quantum yields three to five times greater than those of the most efficient isoluminols in use at present.
A direct method for the preparation of tertiary 3-amino-propenones and 3-aminopropenoates from β-diketones and β-keto esters, and secondaryamines has been developed. The reaction is performed without solvent in the presence or absence of Lewis acid as catalyst, depending on the reactivity of both the amine and the diketo substrate.