SU523091A1 - Derivatives of 2-phenacyltetrahydro-3,4,5,6-pyrazinone-3, possessing anti-inflammatory activity - Google Patents

Description

acids with ethylene diamine in an environment of boiling inert solvent at 100-120 ° С 2.

Example 1. 2- Phenaciltetrahydro-3,4, 5,6 - pyrazinone - 3.

To a boiling toluene solution of 4.12 g (0.02 g-mol) of benzoyl pyruvic acid methyl ester and stirring very slowly an alcohol solution of 1.2 g (0.02 g-mol) of ethylene diamine is added dropwise. After the completion of the dropping, the reaction mixture is heated for another 30 minutes. After cooling during the reflux in the refrigerator, the crystallized substance is filtered off.

Obtain 3.5 g (81%) of yellow crystals with T. Il. 217 ° C.

After recrystallization from C2H50N, m.p. 22GS.

Found: -N 13.39%.

Ci2Hi2O2N2

Calculated: N 12.95%.

Example 2. 2 - p - Chlorfenaciltetrahydro - 3,4,5,6 - pyrazinon-3.

Similarly, from 5 g (0.02 g-mol) of ethyl ester of α-chlorobenzoyl pyruvic acid and 1.2 g of ethyldiamine, 4.2 g (85%) of the substance with m.p. 244 ° C.

Found: N 11.41%.

Ci2Hn02N2Cl

Calculated: N 11.2%.

Example 3. 2 - l - Methylphenacyltetrahydro - 3,4,5,6 - nirazinon - 3.

Similarly, from 2.4 g of ethyl ester "-methylbenzoylpyruvic acid and 0.6 g of etilepdiamip get 2.36 g (96%) of the substance with so pl. 224 ° C.

Found: N 12.79%.

Ci3Hi202N2

Calculated: N 12.2%.

Example 4. 2-p-Bromfenaciltetrahydro-3,4,5,6 - cyrazinon-3.

In Example 1, from 6 g (0.02 g-mol) of p-bromobenzoyl pyruvicogradic acid ethyl ester and 1.2 g (0.02 g-mol) of ethylenediamine, 4.65 g (79%) of the indicated target product with a melting point . 257 ° C.

Found,%: N 9.79; Br 27.25.

Cl2HuO2N2Br.

Calculated,%: N 9,5; Вг 27.1.

Example 5. 2 - p - Methoxyphenacyltetrahydro - 3,4,5,6 - pyrazinone-3.

In Example 1, out of 4.5 g (0.018 g-mol) of p-methoxybenzoyl-pyruvic acid ethyl ester and 1.1 g (0.018 g-mol) of ethylenediamine, 3.9 g (88%) of the indicated target product with a mp. 224 ° C.

Found: N 11.64%. С1зНиОзМ2.

Calculated: N 11.4%.

The synthesized compounds are crystalline substances of yellow color with high melting points, well soluble in alcohol and little soluble in acetone, benzene, chloroform.

IR spectra of the synthesized compounds are fully consistent with the given

structure. The spectrum contains Li 1690 CM (stretching vibrations of amide carbonyl), 1610 (stretching vibrations of ketone carbonyl), 1580 cm (bond C N) and there is no absorption,

characteristic of the primary amino group. The cyclical structure of the synthesized compounds is also evidenced by the identity of the products formed by the interaction of ethyl and methyl

benzoyl pyruvic acid esters with ethylene diamine. The UV spectra of the compounds obtained contain Yamax 350-370 nm.

Claims (2)

1. Derivatives 2 - phenacyltetrahydro-3, 4,5,6 - pyrazinone-3 of the general formula B v NPS-- VO HnC-v. , N where R is a hydrogen atom, chlorine, bromine, methyl, methoxy group, possessing anti-inflammatory activity. 2. 2 - p - Methylphenacyl-3,4,5,6 - tetrahydropyrazinone - 3. Sources of information taken into account in the examination 1. Patent of England No. 980387, cl. C 2c; 01.25.62. 2. R. Elderfield, Heterocyclic Compounds, 1960, Vol. 6,336.