The synthesis of methyl 2‐(benzyloxycarbonyl)amino‐3‐dimethylaminopropenoate. The synthesis of trisubstituted pyrroles, 3‐amino‐2H‐pyran‐2‐ones, fused 2H‐pyran‐2‐ones and 4H‐pyridin‐4‐ones (original) (raw)

1999, Journal of Heterocyclic Chemistry

Methyl 2‐(benzyloxycarbonyl)aimno‐3‐dimemylaminopropenoate (2) was prepared from methyl N‐(benzyloxycarbonyl)glycinate (1) and t‐butoxybis(dimethylamino)methane, and used as a reagent for preparation of substituted 3‐(benzyloxycarbonyl)amino‐4H‐quinolizin‐4‐ones 5 and 6, −2H‐pyran‐2‐ones 17–19, −2H‐1‐benzopyran‐2‐ones 28–31, and ‐naphthopyrans 32–35, −2H‐pyrano[3,2‐c]pyridine‐2,5‐dione 46, ‐pyrano‐[4,3‐b]pyran‐2,5‐dione 47, ‐pyrano[3,2‐c]benzopyran‐2,5‐dione 48, ‐pyrano[2,3‐c]pyrazol‐6‐ones 49 and 50, ‐pyrano[2,3‐d]pyrirnidin‐7‐ones 51 and 52 derivatives. In the reaction of 2 with 1,3‐diketones trisubsti tuted pyrroles 14–16 were formed. Selective removal of benzyloxycarbonyl group was achieved by cat alytic transfer hydrogenation with Pd/C in the presence of cyclohexene to afford free 3‐amino compounds 7, 8, 20, 36–38 and 53–57 in yields better than 80%.