ISSN:
0894-3230
Keywords:
Organic Chemistry
;
Physical Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
The ionization constants of nine amphoteric 5-pyridylmethylenehydantoins were measured in 80% (w/w) dimethyl sulphoxide-water at 25 °C. The effects of structure and Z/E configuration on both pKaI and pKaII values are discussed. The especially low basicity and acidity of the Z-isomers of the N-unsubstituted and 3-methyl-substituted 5-(2-pyridylmethylene)hydantoin are attributed to the formation of intramolecular N(1)—H…N hydrogen bond in the s-cis conformation of these compounds. The existence of N(1)—CH3…N attraction is also postulated for the Z-isomer of 1-methyl-5-(2-pyridylmethylene)hydantoin.
Additional Material:
4 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/poc.610031103