Reaktion von 1,3‐Oxazin‐6‐onen mit Inaminen und Keten‐N,O‐acetalen

Heterocyclic β‐Enamino Esters, 48 1) Heterocondensed Pyridines by Cycloaddition‐Extrusion Sequence of Bi‐ and Tricyclic 1,3‐Oxazinones with N,N ‐Diethyl‐1‐propynylamine

“…Additionally, the new heterocondensed 1,3-oxazinones 6, 8,10, 12 have been prepared on the same route by acylation of the 2-amino group of 5b, 7b, 9b, l l b and subsequent ring closure with the aid of dihalotriphenylphosphoranes. with subsequent C 0 2 expulsion to furnish pyridines, and employing ynamines this transformation reaction has been also observed with 4H-3,l-benzo~azinones'~).…”

ChemInform Abstract: Heterocyclic β‐Enamino Esters. Part 48. Heterocondensed Pyridines by Cycloaddition‐Extrusion Sequence of Bi‐ and Tricyclic 1,3‐Oxazinones with N,N‐Diethyl‐1‐propynylamine.

“…-MS: m/z = 290 (M+). (C-12), 129.09 (C-9,-13), 129.42 (C-14), 131.59 (C-ll), 134.79 (C-l5), C17H10N203 (290.3) Calcd.C 70.34 H 3.47 N 9.65 Found C 71.02 H 3.59 N 9.54 2,3]oxazin-4-one(12) is obtained like 10 from 0.76 g (3.2 mmol) of hexachloroethane, 0.86 g (3.2 mmol) of triphenylphosphane, 1.0 g of 11 b in 20 ml of dry acetonitrile, and 1 ml of triethylamine solved in 5 ml of acetonitrile; yield 0.38 g (41 %), yellow crystals of m.p. 224°C.…”