SU374308A1 - METHOD FOR OBTAINING 1,4-DIHYDRAIN DERIVATIVES IMIDAZO- - Google Patents

Description

one

The invention relates to a process for the preparation of imidazotriazine derivatives, which can be used in the pharmaceutical industry or in organic synthesis.

There are two known methods for the preparation of 1,4-dihydro-derivatives of imidazo- (2,1-c) -triazine-1,2,4. For example, a method is known in which the substituted imidazo- (2,1-c) -triazine-1, 2.4 is subjected to reduction with sodium borohydride followed by isolation of the products by known methods. However, this method is complicated by the fact that the substituted imidazo (2,1-c) -triazine-1,2,4 used as starting materials is usually obtained either by oxidation of 1,4-dihydro derivatives (i.e., the target products obtained from this method), or by condensation of Z-amino-1,2,4 triazine with bromoketon. The latter reaction results in a mixture of two isomeric imindazo- (2,1-c) -triazin1a-1,2,4 derivatives, the separation of which is very difficult because of the closeness of their properties.

A known method for the preparation of 1,4-dihydro-derivatives of imidazo- (2,1-c) -triazin-1,2,4 of the general formula:

B -R

1 Lo

y-tg-

Vf

at,

where R, Ri, Cs have the same or different meanings — hydrogen, alkyl, aryl, Ka-alkyl, aryl, or a residue of a pn-six-membered heterocycle — are characterized by the complexity of the process.

According to the proposed method, in order to simplify the process, 1-acylalkyl-2-haloimidazole is condensed with hydrazine hydrate or its monosubstituted derivative, followed by isolation of products in a known manner; the process is conducted in an organic solvent medium. The intermediate hydrazones of 1-acylalkyl-2-haloimidazole formed in the first stage, as a rule, are not isolated, and with preferably 180-190 cyclized in an autoclave. Products are isolated in a known manner. Yield 65-70%.

The proposed method allows the reaction to be carried out in a single step. Using available source materials, which can be obtained in a known manner.

Example 1. 1,4-Dihydro-3-p-bromophenyl 6, 7-diphenyl.-imidazo- (2,1-c) -triaz1 H-1,2,4. To a suspension of 4.96 g (0.01 mol) of 1-l-bromophenacyl-2-bromo-4, 5-biphenyl-1-HM-imidazole in 20 ml of methanol, 1.47 g (0.025 mol) of 85% psbrazinehydrate was added. The mixture is heated in a stainless steel autoclave (50 ml capacity) at 180-190 ° for 10 hours, then cooled, the precipitate is filtered, washed with water and then with aqueous methanol. The output of 3 g (70%), so pl. 285-288 ° (with decomposition from aqueous dimethylformamide).

Found%: C 64.56; H 4.10; N 13.31;

C23Hi7N4Br.

Calculated%: C 64.34; H 3.99; N 13.05.

Example 2. 1,4-Dihydro-1,3,6,7-tetrafinylimidazo- (2,1-c) -triazin-1,2,4. A mixture of 4.17 g (0.01 mol) of 1-phenacyl-2-bromo-4,5-diphenylimidazole and 2.7 g (0.025 mol) of phenylhydrazine in 20 ml of methanol is heated and worked up as in Example 1. The yield of 2.77 g (65%), t. Pl. 248-250 ° (with decomposition from aqueous dimethylformamide).

Found,%: C 81.31; H 5.10; N 13.24;

C29H22N4 Calculated,%: C 81.66; H 5.20; N 13.14.

Subject invention

Claims (2)

1. A method for preparing 1,4-dihydropro-derivative imidazo- (2,1-c) -triazin-1,2,4 of the general formula: Ky R. hgvt x II / N N N RI where R, RI, Rz can have the same or different values - hydrogen, alkyl or aryl, R-2 is alkyl, aryl or a residue of five to six membered heterocycle, characterized in that, in order to simplify the process, 1-acylalkyl-2 -halogenimidazole is subjected to condensation with hydrazine hydrate or its monosubstituted derivative, followed by isolation of products in a known manner. 2. A method according to claim 1, characterized in that the process is conducted in an organic solvent medium.