ChemInform Abstract: SYNTH. UND EIGENSCHAFTEN VON AMIDINEN

Abstract

Die Reaktion der N‐Li‐aniline (I) (dargestellt aus entsprechenden Anilinen mit Phenyl‐Li in siedendem Diäthyläther) mit Benzylcyanid (II) in siedendem Di‐ äthyläther liefert bei nachfolgender Hydrolyse der entstehenden Li‐Salze die Amidine (III).

Amidines. Part 32. Influence of substitution at the amino nitrogen atom on the sensitivity to substitution at the imino nitrogen atom. pKaValues of N1-methyl-N1-phenylformamidines in water–ethanol solutions

“…Obtained pKa values were corrected according to the known relation 2 2 given in eqn. (5) where the pH value is measured at the 1/2 neutralization point, pKai and pKa5 are the pKa values of the compound investigated (i) and the standard (s). Imidazole was used as the standard for pK, determination.…”

Amidines. Part 28. Influence of substitution at the amidino carbon atom on the sensitivity to substitution at the imino nitrogen atom. pK a Values of N 1 N 1-dimethylbenzamidines

“…Linear Correlations with the pKa Values of Amines.-As in previous papers we have correlated the pKa values of the amidines with the pKa values of the corresponding primary amines measured under the same condition^. ',^^ Parameters of the regressions [equation (4)] are summarized in Table 3. pKa(amidine) = pe(amidine) + a1,[pKa(RxNH2) -pKa(PhNH,) (4) The correlations of pKa values of amidines with the pKa values of the corresponding primary amines are of very good quality, as indicated by the correlation coefficient r and Exner's Y function.…”

“…',^^ Parameters of the regressions [equation (4)] are summarized in Table 3. pKa(amidine) = pe(amidine) + a1,[pKa(RxNH2) -pKa(PhNH,) (4) The correlations of pKa values of amidines with the pKa values of the corresponding primary amines are of very good quality, as indicated by the correlation coefficient r and Exner's Y function. The parameters of these equations can be used for fairly accurate prediction of the pKa values of amidines of various series, containing alkyl, aryl, or aralkyl substituents at the imino nitrogen atom.…”