RU2306315C1 - Method for production of e-2-aroylmethylene-1-phenyl-1,2,3,4-tetrahydroquinazolin-4-ones - Google Patents

Abstract

FIELD: organic chemistry.

SUBSTANCE: invention relates to new method for production of E-2-aroylmethylene-1-phenyl-1,2,3,4-tetrahydroquinazolin-4-ones of general formula I

wherein R represents H, methyl, Cl. Claimed method includes interaction of 5-aryl-2,3-dihydro-2,3-furandiones with N-phenylanthranyl acid amide in medium of inert aprotic solvent (preferably benzene) followed by isolation of target products. Process is carried out preferably at 79-80°C. Claimed compounds have fluorescent properties and are useful in labeling and copying agents, intermediates for synthesis of new heterocyclic compounds, etc.

EFFECT: new fluorescent compounds.

3 cl, 1 dwg, 3 ex

Description

The invention relates to the field of organic chemistry, namely to new individual compounds of the quinazolinone class and to a method for their preparation, which exhibit fluorescent properties and can be used as starting materials for synthesis, new heterocyclic systems, and also as substances for labeling samples and additives for reflective paints.

Benzoxazin-4-ones with an aroylmethylene group in position 2 are known, having stable fluorescence, which can be used as labels for protecting documents and additives in reflective paints (see US Pat. RF No. 2240333, publ. 20.11.04).

Derivatives of quinazolin-4-one with aryl substituents in position 2 or quinoxalines, a ethoxycarbonylmethylene group in position 2, possessing stable fluorescence (see B.M. Krasovitsky, B.M. Bolotin "Organic phosphors", published by Chemistry, Moscow, p. 112-114).

Structural analogues of the claimed compounds E-2-ethoxycarbonylmethylene-1-substituted-1,2,3,4-tetrahydroquinazolin-4-ones are known from the literature (Chem. Pharm. Bull. 1983. Vol.31. No. 7. P. 2234 -2243).

The synthesis is carried out according to the following scheme:

In this way it is impossible to obtain E-2-aroylmethylene-1-phenyl-1,2,3,4-tetrahydroquinazolin-4-ones, exhibiting fluorescent properties.

The objective of the invention is to develop a simple, one-step method for obtaining not described in the literature E-2-aroylmethylene-1-phenyl-1,2,3,4-tetrahydroquinazolin-4-ones, exhibiting fluorescent properties, as well as expanding the arsenal of agents used as labels to protect documents from copying and additives to reflective paints.

The task is carried out by boiling 5-phenyl-2,3-dihydro-2,3-furandion with N-phenylanthranilic acid amide in an inert aprotic solvent according to the scheme:

The process is carried out at a temperature of 79-80 ° C, and benzene is used as an inert aprotic solvent.

Compounds II (a-c) in the solid state possess stable fluorescence (radiation in the yellow light region at λ = 580-595 nm) when irradiated with a UV lamp λ = 254 nm. Fluorescence is maintained when samples are stored under normal conditions for a long time.

From the patent and technical literature, no methods have been identified for the preparation of E-2-aroylmethylene-1-phenyl-1,2,3,4-tetrahydroquinazolin-4-ones, on the basis of which we can conclude that the claimed technical solution meets the criteria of patentability "novelty" and "inventive step".

The invention is illustrated by the following examples.

Example 1

E-2-phenacylidene-1-phenyl-1,2,3,4-tetrahydro-4-quinazolone.

A solution of 1.42 g (8.15 mmol) of 5-phenyl-2,3-dihydro-2,3-furandion (compound Ia) and 1.73 g (8.15 mmol) of N-phenylanthranilic acid amide in 25 ml of absolute benzene is boiled for 3 hours, cooled , the precipitate formed is filtered off, crystallized from benzene. 1.22 g (44%) are obtained. Compound IIa. C ₂₂ H ₁₆ N ₂ O _{2. Mp} 299-300 ° C.

Found,%: C 77.60; H 4.75; N, 8.25.

Calculated,%: C 77.63; H 4.74; N, 8.23.

Example 2

E-2-p-Toluoylmethylene-1-phenyl-1,2,3,4-tetrahydro-4-quinazolone.

A solution of 1.53 g (8.15 mmol) of 5-p-tolyl-2,3-dihydro-2,3-furandion (compound Ia) and 1.73 g (8.15 mmol) of N-phenylanthranilic acid amide in 25 ml of absolute benzene are boiled for 3 hours , cooled, the precipitate formed is filtered off, crystallized from benzene. Obtain 1.30 g (46%). Compound IIb. C ₂₃ H ₁₈ N ₂ O ₂ . _Mp 253-255 ° C.

Found,%: C 77.95; H 5.13; N, 7.92.

Calculated,%: C 77.93; H 5.12; N, 7.90.

Example 3

E-2-p-Chlorobenzoylmethylene-1-phenyl-1,2,3,4-tetrahydro-4-quinazolone.

A solution of 1.70 g (8.15 mmol) of 5-phenyl-2,3-dihydro-2,3-furandione (compound Ia) and 1.73 g (8.15 mmol) of N-phenylanthranilic acid amide in 25 ml of absolute benzene is boiled for 3 hours, cooled , the precipitate formed is filtered off, crystallized from benzene. Obtain 1.12 g (37%). Compound IIc. C ₂₂ H ₁₅ ClN ₂ O ₂ . _Mp 250-251 ° C (from benzene).

Found,%: C 70.48; H 4.04; Cl 9.50; N, 7.50.

Calculated,%: C 70.50; H 4.03; Cl 9.46; N, 7.47.

Compounds II (a-c) are colorless, high-melting crystalline substances, readily soluble in DMSO, DMF, insoluble in benzene, alcohol, insoluble in water and alkanes.

In the PC spectra of compounds II (a-c), taken in liquid paraffin, there is a wide stretching band of the NH group involved in the formation of the H-chelate type air force in the region of 3060-3080 cm ^-1 , the absorption band of the lactam carbonyl group of the quinazoline cycle in region 1670-1690 cm ^-1 , a wide absorption band of an aroyl carbonyl group involved in the formation of an intramolecular hydrogen bond of the H-chelate type, in the region 1605-1615 cm ^-1 .

In the ¹ H NMR spectra of compounds II (a-c), taken in solution in DMSO-d ₆ , in addition to the signal group of aromatic protons in the region of 6.43-8.24 ppm there is a vinyl proton singlet in the region of 4.90-4.99 ppm, a proton singlet of the NH group in the region of 14.59-14.71 ppm. and a singlet of protons of the methyl group at 2.33 ppm (compound IIb).

In the ¹³ C NMR spectrum of compound IIa, along with the signals of carbon atoms of aromatic rings in the region of 123.84-142.91 ppm there is a signal of the vinyl carbon atom of the phenacylidene fragment at 79.29 ppm, signals of the carbon atoms of the quinazolone cycle at 116.88 (C ^4a ), 142.60 (C ^8a ), 154.56 (C ⁴ ), 158.49 (C ² ) and the ketone carbonyl C OPh at 186.08 ppm, which is in good agreement with the proposed structure.

The proposed method is simple to implement, one-step and allows to obtain E-2-aroylmethylene-1-phenyl-1,2,3,4-tetrahydroquinazolin-4-ones not described in the literature with a yield of 37-46%.

The optical activity of the proposed compounds allows you to use them individually and in compositions for applying fluorescent labels, invisible in normal lighting, on banknotes or documents requiring copy protection.

In a mixture with dyes, they can be used for the manufacture of fluorescent paints, the luminescence of which is caused by UV and short-wave visible radiation.

Claims (3)

1. The method of obtaining E-2-aroylmethylene-1-phenyl-1,2,3,4-tetrahydroquinazolin-4-ones of the General formula

where R-H (a), CH ₃ (b), Cl (c), characterized in that 5-aryl-2,3-dihydro-2,3-furandiones are reacted with N-phenylanthranilic acid amide in an inert aprotic solvent, followed by isolation of the desired products. 2. The method according to claim 1, characterized in that the process is carried out at 79-80 ° C. 3. The method according to claim 1 or 2, characterized in that benzene is used as an inert solvent.