Equilibrium NH acidities of acridan,phenanthridone, 9-acridone,and substituted 9-acridones

The equilibrium NH acidities of acridan, phenanthridone, 9-acridone, and 2-substituted 9-acridones (substituents: Me₂N, MeO, F, Br, I, and NO₂) were measured by transmetallation in dimethyl sulfoxide (DMSO). The role of conjugation and the aromatic character of the heterocyclic ring in stabilization of the anions is discussed. The energies of deprotonation of phenanthridone and 9-acridone were estimated by the CNDO/2 (complete neglect of differential overlap) method; it is shown that the difference between them is in agreement with the experimental results. The dependence pK = 16.2 – 3.37_I – 1.84_R (s 0.23, r 0.989) was obtained for the 2-substituted 9-acridones.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1241–1244, September, 1982.We thank É. S. Shcherbakova for her assistance in the correlation analysis of the data on the acidities of the substituted 9-acridones.     

Synthesis of Unsaturated Carboxylic and Amino Acids of Adamantane Series with the Use of Organophosphorus Reagents

Sodium derivative of diethyl(3-amino-1-ethoxycarbonylpropane)phosphonic acid was obtained by reaction of triethyl phosphonoacetate with ethylene imine in the presence of sodium hydride. The compound obtained was brought into Horner-Emmons reaction with carbonyl derivatives of adamantane series to afford the corresponding unsaturated amino acids. From adamantanecarbonyl chlorides and triphenylphosphonium ethoxycarbonylmethylide were prepared new phosphorus acylylides that on thermolysis provide ethyl acetylenecarboxylates containing an adamantyl substituent.