✍ Scribed by Kunio Ito; Shingo Miyajima
No coin nor oath required. For personal study only.
Methyl (E)‐4,4‐dimethyl‐5‐oxo‐2‐pentenoate (1, X = O) reacted with 1,2‐ or 1,3‐aminoalcohols 3 to yield oxazolidines 4a‐c or tetrahydro‐1,3‐oxazines 4d,e. The corresponding imino ester 1 (X = NBu‐t) also gave 4 on reaction with 3. Compounds 4 on heating at 230° yielded 4,5‐dihydrooxazoles 5a‐c or 5,6‐dihydro‐4__H__‐1,3‐oxazines 5d,e along with methyl 4‐methyl‐3‐pentenoate (6).
📜 SIMILAR VOLUMES
\(N\) - \(t\)-Butylbenzamidines 1 reacted with diphenyl phenylmalonate or diphenyl methylmalonate to give 6-hydroxypyrimidin-4(3H)-ones 4 or 5 . Amidines 1 on reaction with diphenyl imidodicarboxylate afforded \(1,3,5\)-triazine- \(2,4(1 H, 3 H)\)-diones 8 .
Retro-Ene Reactions in Heterocyclic Synthesis. Part 4. A New Synthetic Method for 6-Hydroxypyrimidin-4(3H)-ones and 1,3,5-Triazine-2,4(1H,3H)-diones. -Reaction of benzamidines (I) with substituted malonates (II) and imidodicarboxylate (IV) provides an efficient access to 6-hydroxypyrimidinones (III
## Abstract magnified image __N__‐__t__‐Butylamidines **1** on heating with diphenyl carbonate (**2**) at 150‐180° gave the 1,3,5‐triazine‐2,4(1__H__,3__H__)‐dione derivatives **5**. Acylation of amidines **1** and cyclocondensation of the resulting carbamates **3** gave [1,3,5,7]tetrazocine‐2,6‐d