title: Decomposition of 1-aryl-3-dimethylamino-1-propanone methobromides under weakly acidic conditions.
abstract: Under basic conditions, some 1-aryl-3-dimethylamino-1-propanone methodbromides (2) were shown to decompose too readily to measure by the electronic absorption spectroscopy technique available. However, at pH = 5.9 and 20 degrees centigrade, the rate of deamination to the corresponding 1-aryl-2-propen-1-ones was able to be followed using Guggenheim's method and a Hammett plot showed that the rate of deamination correlated with the arly substituent constants (o). The rho value for this process was +1.00. In contrast the corresponding 1-arly-3-dimethylamino-1-propanone hybrobromides (1) did not decompose under simulated physiological conditions (pH = 7.4, 37 degrees centigrade). Neither 1 or 2 were active against P388 lymphocytic leukemia in mice but the methobromides displayed greater murine toxicity.
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000138:chemical synthesis*; D055598:Chemical Phenomena; D002621:Chemistry; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D007928:Lethal Dose 50; D007941:Leukemia P388 / Q000188:drug therapy; D051379:Mice; D011427:Propiophenones / Q000138:chemical synthesis* / Q000627:therapeutic use / Q000633:toxicity
chemical_list: D000970:Antineoplastic Agents; D011427:Propiophenones