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Chemical and biological studies on dihydro‐ s ‐triazines. XVI. Nmr evidence for the formation of 2‐guanidino‐4‐methylquinazolines as anomalous byproducts in the three‐component synthesis
Author(s) -
Rosowsky Andre,
Modest Edward J.
Publication year - 1972
Publication title -
journal of heterocyclic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.321
H-Index - 59
eISSN - 1943-5193
pISSN - 0022-152X
DOI - 10.1002/jhet.5570090326
Subject(s) - chemistry , acetic acid , acetone , component (thermodynamics) , aryl , carbon 13 nmr , organic chemistry , proton nmr , nuclear magnetic resonance spectroscopy , medicinal chemistry , alkyl , physics , thermodynamics
The three‐component synthesis of 4,6‐diamino‐1‐aryl‐1,2‐dihydro‐2,2‐dimethyl‐ s ‐triazines from arylamines. cyanoguanidine, and acetone has been studied by nmr spectral analysis in trifluoro‐acetic acid solution. The presence of 2‐guanidino‐4‐methylquinazoline contaminants can be discerned clearly at concentrations as low as 1%. Arylamines most likely to give significant proportions of guanidinoquinazoline byproducts are 2‐naphthylamines and anilines containing one or more electron‐donating meta ‐substituents.