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Quite unlike the reported facile ene reactions on the periphery of many related heterocyclic systems, similarly disposed moieties on the periphery of the chromen-4-one ( 4H-1-benzopyran-4-one) system fail to undergo an ene reaction and display a rather unusual preference for an overall [1,5] shift of the allylic C-atom. Thus, heating xylene solutions of 2-(N-allylanilino)-, 2-(N-crotylanilino)-, and 2-(N-cinnamylamino)-substituted (E)-(oxochromenyl)propenoates 9a ± c and 2-[allyl(benzyl)amino]-, 2-[benzyl(crotyl)amino]-, and 2-[benzyl(cinnamyl)amino]-substituted (E)-(oxochromenyl)propenoates 16a ± c in a sealed tube at 220 ± 2308 leads to a [1,5] shift of the allylic moieties (allyl, crotyl, cinnamyl), which is followed by intramolecular cyclization involving the N-atom and the ester function, to give the 3-allyl-3-crotyl-, and 3-cinnamyl-substituted- Introduction. ± Recently, ene reactions on the periphery of a number of heterocyclic systems such as pyridinones, pyrimidinones, pyrido[1,2-a]pyrimidinones, and coumarin ( 2H-1-benzopyran-2-one) have been utilized [1] to obtain heteroannulated azepines 1 ± 3 (Scheme 1), which are anticipated to display useful biological activities; an intramolecular hetero-DielsÀAlder reaction has been reported to intervene only in one case leading to a minor product 4 (Scheme 1). Subsequent kinetic and theoretical investigations on these reactions have also been reported [2], which support a concerted mechanism for these transformations.We have recently reported [3] that C-(4-oxo-4 H-1-benzopyran-3-yl)-N-phenylnitrone 5 undergoes intramolecular rearrangement to 2-anilino-4-oxochromene-3-carboxaldehyde (6) in 70 ± 90% yield and 3-(anilinomethylene)chromene-2,4-diones (7) in 10 ± 25% yield (Scheme 2), and that the yield of 6 could be improved to > 95% by refluxing 5 in benzene under acidic conditions [3b]. It was, therefore, decided to utilize 6 to investigate similar reactions at the periphery of the chromen-4-one ( 4H-1-benzopyran-4-one) system. The investigations were of considerable interest as the targeted azepino-chromenones were potentially biologically active molecules.

Synthesis of Isatin-N 1-methyl-thiosemicarbazone (H 2 itsc-N 1-Me, H 2 L 1) and isatin-N 1-ethylthiosemicarbazone (H 2 itsc-N 1-Et, H 2 L 2) has been carried out and the effect of substituents (at N 1 atom of isatin-3-thiosemicarbazones) on nuclearity of copper(I) halide complexes has been investigated. Reactions of copper(I) halides (X = I, Br, Cl) with H 2 L 1 and H 2 L 2 using Ph 3 P as coligand in 1 : 1 : 1 (M : L : PPh 3) molar ratio in acetonitrile yielded complexes of stiochiometry [CuX(H 2 L 1)(Ph 3 P)] (X = I, C1; Br, C2; Cl, C3) and [CuX(H 2 L 2)(Ph 3 P)] (X = I, C4; Br, C5; Cl, C6) respectively. All these complexes have been characterized using analytical and spectroscopic data (IR, 1 H NMR and ESI mass). The single crystal structure has been solved for H 2 L 1 and C2. The complex C2 has distorted tetrahedral geometry around copper(I) and isatin

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