The thermal ring transformation of 2‐substituted 4‐oxo‐4H‐pyrido[1,2‐a]pyrimidine‐3‐acrylates gave 2‐substituted 1,8‐naphthyridine‐3‐acrylates, pyrano‐1,8‐naphthyridines and anthyridine, depending upon the nature of the 2‐substituent. A longer reaction period and a higher reaction temperature favored the formation of tricyclic products from 1,8‐naphthyridine‐3‐acrylate after isomerization of the side‐chain at position 3. The products were characterized by means of uv, ir and 1H nmr spectroscopy.
ASJC Scopus subject areas
- Organic Chemistry