No abstract

Keywords: 2-hydrazino-3,4,5,6-tetrahydro-2H-azepine, 2,3-dioxopyrrolo[2,1-a]isoquinolines, 3,3-dimethyl-1-(1,2,4-triazolo[4,5-a]azepan-8-ylcarbonylmethylideno)-1,2,3,4-tetrahydroisoquinolines, opening of the dioxopyrroline ring.In previous work [1, 2], we showed that the reaction of 2,3-dioxopyrrolo[2,1-a]isoquinolines with several dinucleophiles might proceed with opening of the lactam bond and concurrent heterocyclization. The reactions of these compounds with cyclic hydrazidines have not yet been reported. In a continuation of a study of the chemical properties of these compounds, we found that dioxopyrrolines 1a,1b readily undergo opening of the pyrroline ring upon moderate heating in benzene to give enamino ketones 2a,b.This method was used to synthesize various compounds with potential biological activity. In the case R = H, the compounds obtained are enamino ketones, which are capable of further transformations.The 1 H NMR spectra were taken on a Bruker-300 spectrometer at 300 MHz in CDCl 3 with HMDS as the internal standard. The IR spectra were taken on a Specord M-80 spectrometer for vaseline mulls. The electron impact mass spectra were taken on an MAT-311 at 70 eV.

No abstract

No abstract

No abstract

No abstract

No abstract

547.913+547.94+547.833.3 E. S. Limanskii, and M. I. VakhrinAlkylation under phase-transfer catalysis conditions (18-crown-6/KOH) of eugenol was used for cyclocondensation with nitriles (Ritter reaction), the products of which were isoquinoline derivatives.Eugenol (1, 4-allyl-2-methoxyphenol) is the main constituent of essential oil from Syzygium aromaticum (Eugenia caryophyllata) (Myrtaceae), Camelia sasanqua (Theaceae), certain basil species (Ocimum) (Lamiaceae), and other plants [1,2].Various isoquinoline derivatives, many of which can be viewed as synthetic alkaloid analogs, were prepared earlier by cyclocondensation of nitriles with dialkylbenzylcarbinols (Ritter reaction) [3]. The capability for this type of cyclocondensation involving instead of a carbinol 3,4-dimethoxy-and 3,4-methylenedioxyallylbenzenes, which are very similar to eugenol, was demonstrated in classical seminal studies [4,5]. The goal of the present study was to use in analogous syntheses eugenol derivatives and nitriles that were verified by us earlier in reactions with carbinols.Syntheses with a protected phenol hydroxyl were carried out first. The studies showed that the eugenol hydroxyl can be alkylated practically quantitatively under phase-transfer catalysis conditions using 18-crown-6/KOH. Alkylation of 1 by iodomethane or iodoethane formed the corresponding ethers 2 and 3, which were used without further purification in the next step of the Ritter cyclocondensation. Use of hydrogen cyanide [6], acetonitrile [7], and homoveratryl nitrile instead of benzylcyanide [8], chloroacetonitrile [9], and 3-cyanocoumarin [10] as the nitrile component formed the corresponding 3,4-dihydroisoquinolines 4-8. By analogy, reaction of allylbenzenes 2 and 3 with cyanoacetic acid amide produced amides 9 and 10 [11]. The fact that the cyclization occurred without protecting the phenol hydroxyl was interesting. The reaction of eugenol with cyanoacetamide gave enaminoamide 11. Me H 8 5 4 1 a b MeO R 1 O NH Me H O NH 2 2, 3 4 -8 c c 9 -114: R 1 = Et, R 2 = H; 5: R 1 = R 2 = Me 6: R 1 = Me, R 2 = 3,4-dimethoxybenzyl; 7: R 1 = Me, R 2 = CH 2 Cl 8: R 1 = Me, R 2 = 3-coumarinyl; 2, 9: R 1 = Me; 3, 10: R 1 = Et; 11: R 1 = H a. R 1 I, 18-crown-6/KOH; b. R 2 CN; c. NCCH 2 C(O)NH 2