N-[(2-Oxopyrrolidin-1-yl)-acetyl]piperazine derivatives and drug for senile dementia

Abstract: A compound of the formula: (wherein R is -SO₂R¹ or -CONHR²; R¹ is C₁-C₅ alkyl, C₈-C₁₂ phenyl­ alkenyl, amino, dimethylamino, optionally substituted C₆-C₁₂ aryl, or 5- or 6-membered heterocyclic group including at least one hetero atom selected from the group consisting of N, S, and O; R² is amino, C₁-C₅ alkylamino, C₁-C₅ alkyl, or optionally substituted C₆-C₁₂ aryl) or its pharmaceutically acceptable acid-addition salt, being useful as a drug for senile dementia, psychotropic, or antiamnesia agent is provided through several routes.

Description: BACKGROUND OF THE INVENTION This invention relates to N-[(2-oxopyrrolidin-1-yl)acetyl]piperazine derivatives. More particularly, this invention is directed to N-[(2-oxopyrrolidin-1-yl)acetyl]piperazine derivatives, to pharmaceutical compositions comprising such a compound, their use for the preparation of a pharmaceutical composition for use in the treatment of senile dementia, psychosis or to their preparation. N-[(2-Oxopyrrolidin-1-yl)acetyl]piperazine derivatives have heretofore been known as useful antiamnesia agents, for example, in GB Unexamd. Pat. Publn. No. 2162843-A and EP Pat. Publn. No. 89900-B. FR-A-2 382 441 discloses N-(aminoalkyl substituted)-2-oxo-1-pyrrolidines which are useful in the treatment of conditions such as senility. In GB-A 2 162 843 psychogeriatric N-((2-oxo-1-pyrrolidinyl) acetyl) derivatives are described. The inventors of the present invention have been studying on antiamnesia agents of the piperazine family including such compounds. Thus, the present invention has been established. Pharmaceutical compositions containing compounds of the present invention can be used for treating some kinds of senile dementia. SUMMARY OF THE INVENTION According to the present invention, there is provided an N-[(2-oxopyrrolidin-1-yl)acetyl]piperazine derivative of the formula: (wherein R is -SO₂R¹ or -CONHR²; R¹ is C₁-C₅ alkyl, C₈-C₁₂ phenylalkenyl, amino, dimethylamino, optionally substituted C₆-C₁₂ aryl, or 5- or 6-membered heterocyclic group including at least one hetero atom selected from the group consisting of N, S, and O; R² is amino, C₁-C₅ alkylamino, C₁-C₅ alkyl, or optionally substituted C₆-C₁₂ aryl) or its pharmaceutically acceptable acid-addition salt. The terms used in the above definition are explained below. As the alkyl, methyl, ethyl, n-propyl, isopropyl, n-butyl, secbutyl, isobutyl, tert-butyl, n-pentyl, and isopentyl are exemplified. As the phenylalkenyl, styryl, phenylpropenyl, phenylbutenyl, and phenylpentenyl are exemplified. Phenyl comprises substituted or unsubstituted phenyl. As the heterocyclic group, thienyl, furyl, pyridyl, and pyrimidinyl are exemplified. As the substituent which may be present on phenyl, the alkyl above-illustrated alkoxy, halogen, acetylamino, and nitro are exemplified. As the halogen, chlorine, fluorine, bromine, and iodine are indicated. As the alkoxy, methoxy, ethoxy, and propoxy are illustrated. The compound (I) of this invention is mainly prepared in accordance with the scheme shown below. (wherein Hal and X each is halogen; R¹ and R² have the same meaning as defined above. In method B, however, R² is alkyl or optionally substituted phenyl). Method A The compound (II) is allowed to react with sulfonyl halide (III) in an appropriate solvent to obtain a compound (Ia). As the solvent, any inert organic solvent that can dissolve the reaction agent can be used. For examples, aromatic solvents such as benzene, toluene, and xylene; alkanols such as methanol, ethanol, and isopropanol; ethers such as dioxane, tetrahydrofuran, diethylene glycol, diethyl ether, and dibutyl ether; dimethylformamide, and dimethyl sulfoxide can be used. Further the reaction may be accelerated by adding a tertiary amine such as triethylamine or pyridine as an acceptor of an acid. The reaction is carried out at a temperature from -20 to 100 °C, preferably -5 to 30 °C. Method B The compound (II) is allowed to react with an isocyanate (IV) in an appropriate solvent to obtain an objective compound (Ib). As the solvent, methanol, ethanol, benzene, chloroform, dichloromethane, and carbon tetrachloride may be used. The reaction is carried out at a temperature from -10 to 100 °C, preferably around room temperature (1 to 30 °C). Method C (1) The compound (II) is allowed to react with phenyl halogenoformate (V) in an appropriate solvent to obtain a compound (VI). As the solvent, methanol, ethanol, benzene, chloroform, dichloromethane, and carbon tetrachloride may be used, and as the acceptor of an acid, bases such as triethylamine or pyridine can be used. The reaction is carried out at a temperature from -10 to 100 °C, preferably around room temperature. (2) The compound (VI) obtained in the preceding step (1) is allowed to react with the amine (VII) to obtain an objective compound (Ib). The reaction is carried out at a temperature from 50 to 150 °C, preferably around 100 °C. Aside from above method A to method C, the following methods are indicated as the synthesis of the objective compound (Ia). (a) (wherein R¹ has the same meaning as defined above; R³ is C₁-C₃ alkyl.) (b) (wherein R¹ has the same meaning as defined above; Hal is halogen; M is a metal atom (e.g. sodium, potassium)). (c) (wherein R¹ has the same meaning as defined above; R⁴ is hydroxy or halogen.) The starting material (II) is produced, for example, in the following process. (wherein R³ has the same meaning as defined above.) The compound (I) can be converted into its pharmaceutically acceptable acid addition salt. Such acids illustratively include inorganic acids such as hydrochloric acid, sulfuric acid, phosphoric acid, nitric acid, hydrobromic acid, and hydrogen iodide and organic acids such as acetic acid, maleic acid, malic acid, citric acid, lactic acid, succinic acid, and methanesulfonic acid. Pharmaceutical compositions containing compound (I) of this invention are effective for treating patients suffering from senile dementia, psychosis, or amnesia and useful as a drug for senile dementia, psychotropic, or antiamnesia agent. The objective compound (I) of this invention can be administered to humans or animals either orally or parenterally. For example, the compound (I) may be orally administered in the form of tablets, granules, powder, capsules or liquid, or parenterally as injection or suppository. These preparations are manufactured in a known process by using additives such as diluents, binders, disintegrators, lubricants, stabilizers, corrigents, suspenders, dispersants, solubilizers and antiseptics. As the diluents, lactose, sucrose, starch, cellulose, and sorbit; as the binders, gum arabic, gelatin, and polyvinylpyrrolidone; and as the lubricants magnesium stearate, talc, and silica gel are exemplified, respectively. When a pharmaceutical composition containing the objective compound (I) of this invention is used in the therapy of senile dementia, a daily dose of about 0.01 to 20 mg/kg of the compound may be orally or parenterally administered once or several times. Embodiments of this invention are illustrated below by indicating Examples, Referential Examples, and Preparations. The abbreviations used in the Examples, Referential Examples, and Tables have the following meanings. Me: methyl, Et: ethyl, i-Pr: i-propyl, n-Bu: n-butyl, Ac: acetyl, MeOH: methanol, EtOH: ethanol, Et₂O: diethyl ether, Et₃N: triethylamine Example 1 1-[(2-Oxopyrrolidin-1-yl)acetyl)-4-(4-methoxybenzenesulfonyl) piperazine 1.030 g (4.88 mmol) of [(2-Oxopyrrolidin-1-yl)acetyl]piperazine (II) was dissolved in 15 ml of dichloromethane, and 1.108 g (5.36 mmol) of 4-methoxybenzenesulfonyl chloride and 0.748 ml (5.36 mmol) of triethylamine were added to the mixture with stirring under ice-cooling and the mixture was stirred for 5 hr. and 45 min. at room temperature and diluted with CH₂Cl₂. The solution was washed with diluted HCl, water, aqueous NaHCO₃, and water, respectively and was dried. After evaporating the solvent, the residue was subjected to silica gel column chromatography (silica gel : 91 g), and was eluted with CHCl₃, - MeOH (30:1 to 9:1 v/v). 1.63 g of crystals obtained from the eluted fraction were recrystallized from MeOH, whereby 1.339 g of the objective compound (yield : 72.0%) were obtained as prisms. Anal. Calcd. (%) for C₁₇H₂₃N₃O₅S C, 53.53; H, 6.08; N, 11.02; S, 8.41 Found (%) C, 53.30; H, 6.06; N, 10.97; S, 8.29 IR (Nujol) : 3082, 1687, 1668, 1598, 1578, 1498, 1458, 1448, 1408 cm⁻¹ NMR (CDCl₃ - CD₃OD = 4:1 v/v) : δ 1.9 - 2.2 (m, 2H), 2.41 (t, J=7Hz, 2H), 3.03 (br, 4H), 3.45 (t, J=7Hz, 2H), 3.61 (br, 4H), 3.89 (s, 3H), 4.04 (s, 2H), 7.05 (d, J=10Hz, 2H), 7.71 (d, J=10Hz, 2H) Examples 2 - 17 (wherein R¹ has the same meaning as defined above.) In the same method as in Example 1, the reactions were carried out under the conditions shown in Table 1, and the objective compounds (Ia) were obtained. Their properties are shown in Table 2. Example 18 1-Methylcarbamoyl-4-[(2-oxopyrrolidin-1-yl)acetyl]piperazine (Ib-1) 700 mg (3.31 mmol) of [(2-oxopyrrolidin-1-yl)acetyl]piperazine (II) was dissolved in 10.5 ml of CH₂Cl₂, and 0.215 ml (3.64 mmol) of methyl isocyanate was added to the mixture under ice-cooling, and the mixture was warmed to room temperature and stirred for 1 hr. After evaporating CH₂Cl₂, the precipitated crystals were washed with Et₂O and collected by filtration. By recrystallizing from EtOH - Et₂O, 856 mg of the objective compound (yield : 96.3%) were obtained as colorless prisms. m.p. : 203.0 - 205.0 °C Anal. Calcd. (%) for C₁₂H₂₀N₄O₃ C, 53.72; H, 7.51; N, 20.88 Found (%) C, 53.77; H, 7.53; N, 20.69 IR (Nujol) : 3347, 1681, 1658, 1620, 1552, 1492, 1469, 1454, 1411, 1398 (cm⁻¹) NMR (CDCl₃ - CD₃OD = 4:1 v/v) : δ 2.14 (q, J=7Hz, 2H); 2.46 (t, J=7Hz, 2H); 2.77 (s, 3H); 3.37 - 3.60 (m, 10H); 4.13 (s, 2H) Examples 19 - 22 (wherein R² has the same meaning as defined above.) In the same method as in Example 17, the reactions were carried out under the conditions shown in Table 3, whereby the objective compounds (Ib) were obtained. Their properties are shown in Table 4. Example 23 1-[(2-Oxopyrrolidin-1-yl)acetyl]-4-hydrazinocarbonylpiperazine (Ib-5) (1) 5.026 g (23.790 mmol) of [(2-oxopyrrolidin-1-yl)acetyl]piperazine was dissolved in 90 ml of dichloromethane, and 3.283 ml (26.169 mmol) of phenyl chloroformate and 3.982 ml (28.549 mmol) of triethylamine were added to the mixture with stirring under ice-cooling. After 10 min., the mixture was warmed to room temperature and stirred for 1 hr. The reaction solution was washed with diluted HCl, aqueous NaHCO₃, and water, respectively. After drying, the solvent was distilled off. The residue was washed with Et₂O and recrystallized from CH₂Cl₂ - Et₂O, whereby 7.710 g of the objective compound (yield 97.8 %)were obtained as prisms melting at 185.0 - 186.0 °C. Anal. Calcd. (%) for C₁₇H₂₁N₃O₄ C, 61.62; H, 6.39; N, 12.68 Found (%) C, 61.56; H, 6.40; N, 12.65 IR (Nujol): 1722, 1679, 1661, 1592, 1494, 1460, 1443, 1419 cm⁻¹ IR (CHCl₃): 1719, 1682, 1664, 1594, 1495, 1461, 1421 cm⁻¹ NMR (CDCl₃) : δ 2.12 (quintet, J=7Hz, 2H), 2.43 (t, J=7Hz, 2H), 3.30 - 3.85 (m, 10H), 4.12 (s, 2H), 7.00 - 7.50 (m, 5H) (2) To 3.380 g (10.200 mmol) of 1-phenoxycarbonyl-4-[(2-oxypyrrolidin-1-yl)acetyl]piperazine was added 10 ml of hydrazine hydrate (100 %), and the mixture was stirred for 30 min. at 90°C. Under the reduced pressure, the solution was concentrated, and the residue was subjected to silica gel column chromatography (silica gel : 273.9 g), and eluted with a solution of CHCl₃ - MeOH - concentrated aqueous ammonia (32:6:1 v/v/v), whereby 1.302 g of the titled compound (yield : 46.8 %) were obtained as prisms. m.p. : 164.0 - 166.0 (°C) (recrystallized from i-propyl alcohol) Anal. Calcd. (%) for C₁₁H₁₉N₅O₃·1/5H₂O: C, 48.41; H, 7.17; N, 25.66 Found (%) C, 48.35; H, 7.12; N, 25.88 IR (Nujol) : 3200, 1683, 1648, 1510, 1500, 1454, 1412 cm⁻¹ NMR (CDCl₃ - CD₃OD = 10:1 v/v) : δ 2.09 (quintet, 2H), 2.44 (t, 2H, J=7Hz), 3.20 - 3.80 (m, 10H), 4.11 (s, 2H) Referential Example (2-Oxopyrrolidin-1-yl)acetylpiperazine To 18,133 g (115 mmol) of methyl 2-oxo-1-pyrrolidinyl acetate was added 19.778 g (230 mmol) of piperazine , and the mixture was heated at 100°C for 2 hours and 20 minutes. After evaporating the excess piperazine under the reduced pressure, the residue was subjected to silica gel column chromatography and eluted with a mixture of CHCl₃ - MeOH - concentrated aqueous ammonia (32:4:0.5 to 32:6:1 v/v/v). The eluted fraction was concentrated under the reduced pressure, whereby 16.856 g of the objective compound (yield : 69.1%) was obtained as crystals. m.p.: 116.0 - 117.0 (°C) (recrystallized from i-propanol - Et₂O) Anal. Calcd. (%) for C₁₀H₁₇N₃O₂: C, 56.85; H, 8.11; N, 19.89 Found (%) C, 56.74; H, 8.08; N, 19.75 IR (Nujol) : 3295, 1676, 1642, 1488, 1463, 1451, 1436, 1408 cm⁻¹ NMR (CDCl₃) : δ 1.87 (br. s. 1H; eliminated by addition of CD₃OD), 1.95 - 2.25 (m, 2H), 2.43 (t, J=7Hz, 2H), 3.84 (t, J=6Hz, 4H), 3.4 - 3.6 (m, 6H), 4.10 (s, 2H) Experiment Prevention against the ECS-Induced Amnesia in Mice The test apparatus was a black acrylic resin box (30 × 30 × 30 cm) with an electrifiable grid floor in which a white wooden platform (10 × 10 × 1 cm) was placed in one corner. The step-down passive avoidance test was conducted on 3 groups of 10 SD mice each (male, 4 to 5 weeks age). A solvent was orally administered to the animals of the first group as a control group and the test compounds at doses of 5 and 50 mg/kg were orally given to other 2 groups 60 min. before the acquisition trial. In the acquisition trail, mice were individually placed on the platform and a scrambled foot shock (3 mA, for 5 sec.) was delivered through the grid floor as soon as the mouse moved off the platform. Five to ten min. after the foot shock, a single electroconvulsive shock (30 mA, 100 Hz (rectangular wave), for 0.2 sec.) was administered transcorneally and then each animal was placed in the home cage. After 24 hr. later, each mouse was again placed on the platform and the latency for descending on the grid floor was measured. A long latency in the retention test indicates good acquisition. The step-down latencies were evaluated using the Mann-Whitney U-test. In Table 5, the results were shown as percent change in latencies over control defined as 100. Effects of Compounds against Amnesia Induced by Electro Convulsive Shock Compound No. 5 mg/kg 50 mg/kg Ia - 4 176 70 5 244 265 8 226 181 Ib - 5 232 340

Claims: Claims for the following Contracting States : AT, BE, CH, DE, FR, GB, IT, LI, LU, NL, SE A compound of the formula: (wherein R is -SO₂R¹ or -CONHR² ; R¹ is C₁-C₅ alkyl, C₈-C₁₂ phenylalkenyl, amino, dimethylamino, unsubstituted phenyl or phenyl substituted by alkyl, alkoxy, halogen, acetylamino or nitro, or 5- or 6-membered heterocyclic group including at least one hetero atom selected from the group consisting of N, S, and O; R² is amino, C₁-C₅ alkylamino, C₁-C₅ alkyl, or unsubstituted phenyl or phenyl substituted by alkyl, alkoxy, halogen, acetylamino or nitro, or its pharmaceutically acceptable acid-addition salt. A compound claimed in Claim 1, namely 1-[(2-oxopyrrolidin-1-yl)acetyl]-4-[(4-fluorobenzene)sulfonyl]piperazine. A compound claimed in Claim 1, namely 1-[(2-oxopyrrolidin-1-yl)acetyl]-4-[(2-phenylethenyl)sulfonyl]piperazine. A compound claimed in Claim 1, namely 1-methylcarbamoyl-4-[(2-oxopyrrolidin-1-yl)acetyl]piperazine. A process for preparing a compound according to Claim 1, which comprises reacting a compound of the formula: with a sulfonyl halide of the formula: Hal-SO₂-R¹ (III) in an inert organic solvent and at a temperature from -20 to 100 °C or a compound of the formula: R²NCO (IV) in methanol, ethanol, benzene, chloroform, dichloromethane, or carbon tetrachloride and at a temperature from -10 to 100 °C (wherein R¹ and R² have the same meaning as defined in Claim 1; Hal is halogen) or comprises reacting said compound (II) with phenyl halogenoformate (V): X-COO-Ph (V) in methanol, ethanol, benzene, chloroform, dichloromethane, or carbon tetrachloride and at a temperature from -10 to 100 °C to give a compound (VI): and reacting a compound (VI) with amine (VII): R²NH₂ (VII) at a temperature from 50 to 150 °C (wherein Ph is phenyl; X is halogen; R² is as defined in claim 1. A pharmaceutical composition comprising a pharmacologically effective amount of a compound according to any of Claims 1 to 4. A pharmaceutical composition for treating patients suffering from senile dementia, psychosis, or amnesia comprising a pharmacologically effective amount of a compound according to any of Claims 1 to 4. Use of the compounds of any of Claims 1 to 4 for the preparation of a pharmaceutical composition. Use of the compounds of any of Claims 1 to 4 for the preparation of a pharmaceutical composition against senile dementia, psychosis or amnesia. Claims for the following Contracting States : ES, GR A process for making a compound of the formula: (wherein R is -SO₂R¹ or -CONHR²; R¹ C₁-C₅ alkyl, C₈-C₁₂ phenylalkenyl, amino, dimethylamino, unsubstituted phenyl or phenyl substituted by alkyl, alkoxy, halogen, acetylamino or nitro, or 5- or 6-membered heterocyclic group including at least one hetero atom selected from the group consisting of N, S, and O; R² is amino, C₁-C₅ alkylamino, C₁-C₅ alkyl, or unsubstituted phenyl or phenyl substituted by alkyl, alkoxy, halogen, acetylamino or nitro, or its pharmaceutically acceptable acid-addition salt comprising when R is -SO₂R¹ reacting a compound of the formula: with a sulfonyl halide of the formula : Hal-SO₂-R¹ (III) in an inert organic solvent and at a temperature from -20 to 100 °C or when R is -CONHR² reacting a compound of formula (II) with a compound of the formula: R²NCO (IV) in methanol, ethanol, benzene, chloroform, dichloromethane, or carbon tetrachloride and at a temperature from -10 to 100 °C (wherein R¹ and R² have the same meaning as defined above; Hal is halogen) or with phenyl halogenoformate (V): X-COO-Ph (V) in methanol, ethanol, benzene, chloroform, dichloromethane, or carbon tetrachloride and at a temperature from -10 to 100 °C to give a compound (VI): and reacting a compound (VI) with amine (VII): R²NH₂ (VII) at a temperature from 50 to 150 °C (wherein Ph is phenyl; X is halogen; R² is as defined above. The process, claimed in Claim 1, wherein the compound of formula (I) is 1-[(2-oxopyrrolidin-1-yl)acetyl]-4-[(4-fluorobenzene)sulfonyl]piperazine, The process claimed in Claim 1, wherein the compound of formula (I) is 1-[(2-oxopyrrolidin-1-yl)acetyl]-4-[(2-phenylethenyl)sulfonyl]piperazine. The process claimed in Claim 1, wherein the compound of formula (I) is 1-methylcarbamoyl-4-[(2-oxopyrrolidin-1-yl)acetyl]piperazine. A process for making a a pharmaceutical composition comprising combining a pharmacolgically effective amount of compound (I) obtainable according to any one of Claims 1 to 4 with a pharmaceutically acceptable carrier.

Inventors: EIGYO MASAMI, HASHIZUME HIROSHI, MATSUMURA HIROMU, MATSUSHITA AKIRA, EIGYO, MASAMI, HASHIZUME, HIROSHI, MATSUMURA, HIROMU, MATSUSHITA, AKIRA
Applicants: SHIONOGI & CO, SHIONOGI & CO., LTD.
Application year: 1988
Main classification: C07D207
IPC codes: C07D207, C07D409, C07D401