Reaction of five‐, six‐, seven‐, and eight‐membered cyclic amidines (1 n = 0‐3) with diethyl ethoxy‐methylenemalonate (2) yields isomeric 2,3‐polymethylene‐4(3H]‐ and 1,2‐polymethytlene‐4(1H)‐pyrimidinones (3 and 4) respectively, n = 0‐3). With 2‐aminopyrroline the isomer ratio was dependent upon the reaction conditions. The structure of the isomers 3 and 4 was studied by uv, ir and 1H‐nmr spectroscopy. Both isomers contain an active methylene group which can be deuterated. Deuteration was investigated with 1H‐nmr spectroscopy.
ASJC Scopus subject areas
- Organic Chemistry