4//-Pyrido pyrimidin -4-ones values

Neurotropic and antistress properties of 2,4-dimethylpyrido[l, 2-u]pyr-imidinium perchlorate were compared with those of piracetam (95MI7). AH-Pyrido[l,2-u]pyrimidin-4-one binds selectively to rat A3 receptors with a A", value of 48/xM. No affinities were observed to rat Ai and A2 receptors (96MI17). 4-Oxo-4//-pyrido[l,2-u]pyrimidine-3-carboxylic acid and -3-carbonitrile did not exhibit significant antibacterial activities (97MI6). 

The octanol-water (pH 5) partition coefficients of alkyl-substituted 4H-pyrido[l,2-a]pyrimidines-4-ones 10 and 11, 3-phenyl and 3-ester derivatives (R2 = Ph, COOEt), and some tetra- and hexahydro derivatives were determined by the classical shake-flask technique at ambient temperature (81MI4 82MI9). Hansch-type 7r values of the substituent (R-R2) were also calculated. The apparent octanol-water partition coefficients of seg-anserine 6 and its 7-methyl derivative were measured (88MI14). The pAa values and apparent octanol-water partition coefficients (at pH 7.4) of risperidone 7 (92MI20, 92MI30), its 9-hydroxy derivative (92MI30), and ocaperidone 8 were reported (92MI20). 

An excellent correlation was determined between octanol-water partition coefficients of 4//-pyrido[ 1,2-a]pyrimidin-4-ones 10 and 11 (R = H, Me, Et R1 = H, Me, Et, nPr R2 = H, Me, Et, Pr) and their RM values measured by TLC on Kieselgel 60 F254 plates with a methanol-water (30 70) mobile phase (82MI9). 

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