SU1482921A1 - Imidazo/1ъ,2ъ:1,6/pyrido/2,3-b/quinoxaline - Google Patents

Abstract

The invention relates to heterocyclic compounds, in particular to 4-amino-5-tosilymidazo [1,2: 1,6] pyrido [2,3-B] quinoxaline, whose derivatives can be used as intermediate products in the synthesis of biologically active preparations . The goal is to create a new heterocyclic system. The target compound is obtained by reacting α-tosyl- [3-chloroquinoxalin-2-yl] -acetonitrile with imidazole in dimethyl sulfoxide in the presence of potassium carbonate, followed by boiling the resulting product in dimethylformamide. Output%: 55

mp, ° С: 326-327

Gross for la C ₂₀ H ₁₅ N ₅ SO ₂ .

Description

The invention relates to a new heterocyclic system, specifically to imidazo [l. \ 2 ’: 1, b ^ pyrido [2,3-c] quinoxaline of the formula

derivatives of which may find application as intermediates in the synthesis of bioactive drugs.

The purpose of the invention is the creation of a new heterocyclic system, derivatives of which can be used in the synthesis of biologically active drugs.

The invention is illustrated by the following examples.

Example. 4-amino-5-tosylimidazo [1, 2 ': 1, b] pyrido [2,3-c] quinoxaline.

a). Getting <A. -tosyl [3- (imidazol-2-yl) -quinoxalin-2-yl] -acetonitrile.

0.71 g (0.002 mol) of A ~ toiyl- [z-chloroquinoxaline-2-acetonitrile is dissolved in 15 ml of dimethyl sulfoxide, 0.136 g (0.002 mol) of imidazole and 0.28 g (0.002 mol) of calcined potassium carbonate are added. The resulting mixture was stirred at 170 ° C for 10 hours, the solvent was removed in vacuo, 20 MP of water was added to the residue, the resulting solution was acidified with 1 ml of acetic acid, and the precipitate was filtered off. Yield 0.73 g <9g%);

SU „„ 1482921

Found,%: N 7.18; S 8.5.

C αο H45 Ny S0 _z .

Calculated,% :. N, 17.98; S 8.23,

T, pl. 210 ° C (from propanol).

b) Preparation of 4-amino-5-tosipimidazo [l '-, 2 ^z : 1, b] pyro ido [2,3 ~ c] quinoxaline.

0.78 g (0.002 mol) of d-tosyl-13- (imidazol-2-ip) quinoxaline-2-ip] acetonitrile is boiled in 10 ml of dimethylformamide for 12 hours, cooled, the solvent is removed in vacuo, 10 is added to the residue, 10 ml of water is filtered off, the resulting precipitate 15 is recrystallized from pyridine. Yield 0.41 g (55%), mp. 326-327 ° C (from dimethylformamide).

Found,%: C 61.3; H 3.9;

N, 18.26; S 8.26. 20

C _hell Щ ₅ n _s so ₂ .

Calculated,%: C 61.49; H 3.87; N, 17.93; S 8.23.

In the IR spectrum of the compound of the general formula recorded in the KBr tablet, 25 absorption bands characteristic of the primary amino group are observed at 3403, 3265 and 3165 cm. The absorption bands corresponding to the sulfonyl group are identified at 1140 ° and 1338 cm ^-4 .

In the PMR spectrum of a compound of the general formula recorded in deuterodimethyl sulfoxide with TMS as an internal standard, the most characteristic is; The presence of two broadened single-proton singlets at 8.29 and §, 54 ppm, exchanging with P ₂ 0 and corresponding to protons of the amino group in the 5th position of the molecule, is significant. Magnetic dd nal The nonequivalence of these protons is due to the coordination of one of them with a nitrogen atom in the 3rd position of the molecule, which confirms the proposed structural formula.

A three-proton inlet corresponding to the protons of the methyl group is observed at 3.31 ppm, aromatic protons of the P-toluenesulfonyl group are observed in the form of a characteristic doublet of doublets at 7.35 and 8.15 ppm, singlets corresponding to protons in 1- mi the 2nd position of the molecule, observed at 8.63 and 7.72 ppm respectively. The paramagnetic shift of the proton signal in the first position of the molecule is due to the de-screening effect of the pair of electrons of the nitrogen atom in the 2nd position of the molecule, which indicates the proximity of these atoms in space and, thus, confirms the proposed cyclic structure.

'The IR spectrum was recorded on an RUE and ICAM SP3 - 300 instrument. The PMR spectrum was recorded on a P - 100 Breker instrument. ·

Thus, a new heterocyclic system was obtained, the derivatives of which can be used in the synthesis of biologically active drugs.

Claims (1)

The claims' Imidazo [1 \ 2 *: 1,6] pyrido [2j3-b] quinoxaline of the formula