Aromatic demethoxylation in the cyclization of 3-(.beta.-dialkoxyarylethylamino)phthalides to 2,3-dihydro-7H-dibenzo[da,h]quinolines

Abstract

2,3-DIHYDR0-7H-DIBENZO [de, h]QUINOLINESrespectively. No unreacted aziridine could be detected after these prolonged reactions at high temperature.Reversibility of the Thermal Valence Isomerization of 1-Cyclohexyl-6-(cyclohexylimino)-la-phenylindano [ 1,241 aziridine. A. Reaction in the Absence of Dipo1arophile.-A deoxygenated solution of 1.15 g (3 mmol) of 4 in 30 ml of toluene was heated to 135-145" for 24 hr giving a deep red color. Evaporation of the solvent and trituration of the residue with ethanol gave recovered indano[l,2-6] aziridine 4 as a slightly yellow solid, mp 158-159", 0.702 g (6lY0 recovery). Evaporation of the ethanol mother liquor afforded 0.068 g (19'%) of 28, 123-124".B. Parallel Reaction in the Presence of a Dipolarophi1e.-A similar experiment was performed with 1.5 g (3 mmol) of 4 and 0.519 g (3 mmol) of N-phenylmaleimide under exactly comparable conditions and resulted in the isolation of adduct 6 (see above), 1.34 g (8O' %), mp 235-236", but no aziridine 4 could be recovered.Reversibility of Photochemical Valence Isomerization of 1-Cyclohexyl-6-(6-cyclohexylimino)-la-phenylindano [ 1,241 aziridine -A solution of 1.063 g (2.8 mmol) of the indano[l,2-b]aziridine 4 in 100 ml of tetrahydrofuran was irradiated under nitrogen a t 0 to -10" in a quartz cell using a 450-W Hanovia high-pressure lamp for 8 hr. A deep red solution was obtainedz4 and when exposed to visible light the color rapidly faded to a pale yellow resulting in a virtually complete restoration of the infrared absorption spectrum of the original compound 4.Photochemical Reaction between l-Cyclohexyl-6-(cyclohexylimino)-la-phenylindano [ 1,2-b] aziridine and Cyclohexylamine Hydrobromide.-A mixture of 1.15 g (3 mmol) of the indano[l,2-b]-aziridine 4 and 1.08 g (6 mmol) of cyclohexylamine hydrobromide in 150 ml of ether and 20 ml of methanol was irradiated for 8 hr under nitrogen with a 450-W high-pressure Hanovia lamp in a quartz reaction vessel. The resulting yellow solid 29 was colected and recrystallized from ether-methanol, 0.527 g (38%): mp 298-299"; ir (CHC13) 1617 (C=N), 3230 cm-l (NH); nmr (24) The very close similarity of the absorption spectrum of this species [Amax (dioxane) 500 mN, 520 (sh), 565 (ah)] to that obtained by heating 4 [Amax (xylene) 505 mN, 534 (ah), and 570 (ah) ] may be noted. ~T M B (CDCla) 0. 20, CeHl,), 3.0-3.6 (m, 1, CHNHC=), 3.9-4.5 (m, 1, =N+CH), 6. 9, aromatic protons), 8.51 (d, 1, D2O exchangeable XH), 9.65 (d, 1, J = 7 Hz, aromatic protons); uvmax (95'3$ EtOH-HBr) 393 mp (log e 4-12), 335 (3.77), 324 (sh, 3.72), 288 (3.86), 279 (3.89); mass spectrum (70 eV) 384.Anal. Calcd for C2,Ha3N2Br: N, 6.02. Found: N, 5.56. The identical compound was obtained by heating the indano-[ 1,241 aziridine with cyclohexylamine hydrobromide or ammonium bromide in toluene.Photochemical Reaction between l-Cyclohexyl-6-(cyclohexylimino)-la-phenylindano [ 1,241 aziridine and cis-1 ,Z-Dichloromethylene.-A mixture of 1.15 g (3 mmol) of the indano[l,2-b]-aziridine 4 and 20 ml of cis-1,2-dichloroethylene in 100 ml of ...

¹H AND 13C NMR SPECTRAL ASSIGNMENTS AND X-RAY CRYSTALLOGRAPHY OF 4,5,8,12b-TETRAHYDRO-ISOINDOLO[1,2 -α ]ISOQUINOLINE AND DERIVATIVES

“…6 We have now confirmed that the LiAlH 4 reduction of lactam 3 generates the expected 5 and a high yield of 4, together with the previously unreported 6. In particular, we have provided convincing proof of the structure of 5 (as its hydrochloride monohydrate 5a) based on a complete study of its 1 H and 13 C NMR spectra, those of 3 and 4, and an X-ray crystallographic analysis of 5a.…”

“…This is of particular interest in relation to the likely DNA interactions of the planar isoindolo[1,2-a]isoquinolin-8-ones and the effect of unprecedented tertiary amines like 5 on enzymes, receptors, structural or transporter proteins. We have now proved beyond all doubt the identity of the latter compound, whose structure has only been reported with some uncertainty in the older literature, 6 and which holds much promise for future elaboration.…”

“…Reduction of 4,5,8,12b-tetrahydroisoindolo[1,2-a]isoquinolin-8one (3) with LiAlH 4 /THF for 48 h under N 2 generated, in moderate yield, 12b-hydroxy-5,6,8,12b-tetrahydroisoindolo[1,2-a]isoquinolin-8-one (4, 55%), plus small amounts of 5,6,8,12b-tetrahydroisoindolo[1,2-a]isoquinoline (5, 6%) and a previously undocumented product, 6 12b-hydroxy-5,6,8,12b-tetrahydroisoindolo[1,2-a]isoquinoline (6) in 3% yield. Walker and Kempton carried out this reduction under slightly different conditions, reporting 23% and 18% yields of 4 and 5, respectively.…”

“…Walker and Kempton carried out this reduction under slightly different conditions, reporting 23% and 18% yields of 4 and 5, respectively. 6 Compound 5 oxidizes rapidly in the presence of air, and therefore its hydrochloride 5a was prepared and studied. The complete 1 H and 13 C NMR assignments of compounds 3-5a, based on oneand two-dimensional NMR experiments (e.g.…”

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ABSTRACT 6,8,isoquinolin-8-one (4), 5,6,8,12b-tetrahydroisoindolo[1,2-a]isoquinoline (5) and 12b-hydroxy-5,6,8,12b-tetrahydroisoindolo[1,2-a]isoquinoline (6) were obtained by reduction of 4,5,8,12b-tetrahydroisoindolo[1,2-a]isoquinolin-8-one (3) with LiAlH 4 /THF/N 2 . The precursor and products were characterized by NMR spectroscopy and the X-ray crystal structure of 5 hydrochloride monohydrate (5a) was determined.

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