Premium
3‐Phenacylidene‐3,4‐dihydro‐1 H ‐pyrido[2,3‐ b ]pyrazin‐2‐ones and 2‐Phenacylidene‐1,2‐dihydro‐4 H ‐pyrido[2,3‐ b ]pyrazin‐3‐ones
Author(s) -
Seki Taketsugu,
Sakata Hisanori,
Iwanami Yasuo
Publication year - 1995
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.5570320157
Subject(s) - chemistry , enamine , condensation , medicinal chemistry , stereochemistry , nmr spectra database , spectral line , organic chemistry , catalysis , physics , astronomy , thermodynamics
Condensation of 2,3‐diaminopyridine ( 1 ) with ethyl o‐, m ‐ and p ‐substituted benzoylpyruvates 2–9 gave two isomeric products. The preferential formation of one or the other isomer has been achieved by different reaction conditions. All the products appear to exist in the enamine form as evidenced by their 1 H nmr and ir spectra.