IE44293B1

IE44293B1 - Novel n-(4(2-oxo-1-benzimidazolyl)piperidion)alkylbenzamide derivatives,processes for their preparation,and pharmaceutical compositions incorporating them.

Info

Publication number: IE44293B1
Application number: IE198276A
Authority: IE
Original assignee: Roussel Uclaf
Priority date: 1975-09-05
Filing date: 1976-09-06
Publication date: 1981-10-07
Also published as: DK142236B; ES451197A1; IE44293L; DK142236C; BE845817A; JPS5233680A; LU75724A1; CH614440A5; NL7609821A; GB1556502A; AT352725B; DE2638705A1; FR2322599A1; FR2322599B1; ATA659076A; CA1140132A; DK398176A

Abstract

The compounds correspond to the formula: <IMAGE> in which R represents hydrogen or a C1-C3 alkyl, n represents the number 2 or 3 and X represents hydrogen, fluorine, chlorine or bromine or a methoxy, trifluoromethyl, nitro or amino radical. They are prepared by reaction of a 4-[3-R-1,3-dihydro-2-oxo-1-(2H)-benzamid-azolyl]-1-piperidine-ethanami ne or -propanamine with a halide of a para-X-benzoic acid. The ethanamine or propanamine involved can be obtained by reaction of a 4-[3-R-1,3-dihydro-2-oxo-1-(2H)-benzamid-azolyl]piperidine with an N-haloethylphthalimide, then treatment of the intermediate product formed with hydrobromic acid in acetic medium and basification. The compounds I and their salts with acids have an antiemetic action and are free of psychotropic properties; they can be used in the treatment and the prevention of cases of vomiting and nausea. [CH614440A5]

Description

This invention concerns novel N-[d-(2-oxo-l-benzimidazolyl)piperidincTj alkyl-benzamide derivatives (hereinafter referred to for convenience as N-substituted benzamide derivatives, processes for the preparation, and pharmaceutical compositions incorporating them.

We have found that certain N-substituted benzamide derivatives 5 possess very interesting pharmacological properties, as will appear hereinafter.

Accordingly, as valuable new compounds, there are provided the N-substituted benzamide derivatives conforming to the general formula: (in which R represents a hydrogen atom or an alkyl radical containing from 1 to 3 carbon atoms, n is 2 or 3, and X represents a hydrogen, fluorine, chlorine or bromine atom, or a methoxy, trifluoromethyl, nitro or amino radical) and the acid addition salts thereof.

The term alkyl radical-containing from 1 to 3 carbon atoms, encompasses methyl, ethyl, n-propyl and iso-propyl radicals.

The acid addition salts may be those formed with mineral or organic acids, and include for example the salts formed with hydrochloric, hydrobromic, hydriodic, nitric, sulphuric, phosphoric, acetic, formic, benzoic, maleic, fumaric, succinic, tartaric, citric, oxalic, glyoxylic and aspartic acids, as well as with alkane-sulphonic acids such as methane sulphonic acid and arylsulphonic acids such as benzene sulphonic acid.

The more especially preferred N-substituted benzamide derivatives in accordance with the present invention are those conforming to general formula I above, in which R represents a hydrogen atom n. is 2 or 3 and X represents a fluorine atom, and of course their acid addition salts with mineral or organic acids.

Of these, the specific preferred compounds are N-[2-(4-(1,3-dihydro-2-oxo-l-(2H)-benzimidazoly1)-l-piperidinyl)-ethyl} -4-fluorobenzamide and its acid addition salts formed with mineral or organic acids, and most especially its hydrochloride.

According to another aspect of the invention there is also provided a process for preparing the N-substituted benzamide derivatives of general formula I above, as well as their salts, in which a starting material of general formula: (in which R and ji have the previously-indicated meanings) is reacted with a benzoyl halide derivative of general formula: A— CO (III) (in which A represents a halogen atom and X has the previouslyindicated meaning) to yield the desired N-substituted benzamide of general formula I in the form of a free base, and if desired the latter is then reacted with a mineral or organic acid to form the acid addition salt Thereof.

The starting materials of general formula II are themselves new compounds, which however can in turn be prepared by reacting a compound conforming to the general formula: (in which R has the previously-indicated meaning) with a halide of formula: (in which Hal represents a chlorine or bromine atom, and £ has the previously-indicated meaning) to form a product of the general formula: 4423 3 (in which R and ri have the previously-indicated meanings) and the latter is subjected to the action of hydrobromic acid in an acetic acid medium to form the hydrobromide of the desired compound of general formula II, which is then rendered alkaline to yield the unsalified starting material of general formula II.

The invention of course extends to the N-substituted benzamides of general formula I and their acid addition salts whenever prepared by the processes herein described.

The N-substituted benzamides of general formula I provided by the present invention, no matter whether made by the processes herein described or otherwise, possess very interesting pharmacological properties. In particular they are endowed with remarkable antiemetic properties, while being practically devoid of psychotropic properties in the main tests for sedative and antipsychotic activity. These properties, which emerge clearly from the experimental results reported hereinafter, indicate the use of the N-substituted benzamides of general formula I, and of course of their acid addition salts formed with pharmaceutically-acceptable acids, as medicaments.

However, before the N-substituted benzamides of general formula I or the acid addition salts thereof can be used in medicine, they should preferably first be formed into pharmaceutical compositions by association with pharmaceutical vehicles.

The term pharmaceutical is used herein to exclude any possibility that the nature of the vehicle, considered of course in relation to the route by which the composition is intended to be administered, could be harmful rather than beneficial. The choice of a mode of presentation, together with an appropriate vehicle is believed to be within the competence of those accustomed to the preparation of pharmaceutical formulations.

According to another aspect of this invention there are therefore provided pharmaceutical compositions which contain one or more of the N-substituted benzamides of general formula I above and/or their acid addition salts formed with pharmacologically-acceptable acids in association with a pharmaceutical vehicle.

The preferred compositions are those wherein the N-substituted benzamide(s) of general formula I above are those in which R represents a hydrogen atom, ji is 2 or 3 and X represents a fluorine atom, as well as their acid addition salts. The specific preferred compositions are those wherein the N-substituted benzamide is N - jj2 - (4 - (1,3 - dihydro - 2 - oxo - 1 (2H) - benzimidazolyl) - 1 - piperidinyl)- ethylj - 4 - fluorobenzamide and/or its acid addition salts with pharmaceutically-acceptable acids, and especially its hydrochloride.

The pharmaceutical compositions of this invention are useful in the treatment of vomiting and nausea of any origin, including vomiting and nausea caused by medicament intolerance and/or by hepato-digestive complaints, and they are also useful in the prevention of nausea and vomiting.

The N-substituted benzamides of general formula I above, and their pharmaceutically-acceptable acid addition salts, can be administered in the form of any pharmaceutical composition intended for the digestive or parenteral route. Thus the pharmaceutical compositions of this invention may be administered orally, perlingually, transcutaneously or rectally, and in respect of these modes, the pharmaceutical vehicle is preferably:8 44283 a) the ingestible excipient of a tablet, such as a coated tablet, a sublingual tablet or a pill; the ingestible container of a capsule or cachet; the ingestible pulverulent solid carrier of a powder; or the ingestible liquid medium of a syrup, solution, suspension or elixir; b) a sterile, iniectable liquid solution or suspension medium; or c) a base material of low melting point capable of releasing the active ingredient to perform its pharmacological function, which base material when appropriately shaped forms a suppository.

Whilst the modes of presentation just listed represent those most likely to be employed, they do not necessarily exhaust the possibilities.

The N-substituted benzamides of this invention may preferably be administered in the form of tablets; of injectable solutions or suspensions dispensed in single-dose ampoules or multi-dose phials; and of suppositories or implants. For administration in these ways the pharmaceutical compositions of the invention can for example be solid or liquid, and can be presented in the pharmaceutical forms currently employed in human medicine, such as for example plain or sugar-coated tablets, gelatin capsules, granules, suppositories and injectable preparations, which can be prepared by conventional methods.

The N-substituted benzamides and/or acid addition salts thereof can be incorporated in excipients conventionally employed in pharmaceutical compositions, such as talc, gum arabic, lactose, starch, magnesium stearate, cocoa butter, aqueous or non-aqueous vehicles, fatty substances of animal or vegetable origin, paraffin derivatives, glycols, various wetting, dispersing or emulsifying agents and/or preservatives.

While the optimum dosages of the N-substituted benzamides of general formula I and/or their acid addition salts may, ' to a certain degree, depend upon the route by which they are to be administered, it can for general guidance be said that, subject to variation according to the product used and patient and the complaint under treatment, the usual dosage rate in the adult male will be from 5 mg to 100 mg per day, bv oral route.

In order that the invention may be well understood it will now be described in more detail, though only by way of illustration, in the following examples.

EXAMPLE 1: Preparation of N-£2-{4-(l,3-dihydro-2-oxo-l-(2H)-benzimidazolyl)-l15 pi peri di nyl)-ethyfj-4-f 1 uorobenzami de.

G of 4-0,3-dihydro-2-oxo-l-(2H)-benzimidazolylj-l-piperidineethaneamine dihydrobromide (prepared as described in Preliminary .

Stages A and B below) were suspended in 450 cc. of anhydrous tetrahydrofuran, and 10 g of sodium carbonate were added.

The mixture was cooled in a bath of iced water, and over a period of 10 minutes 7.7 ccs. of £-fluoro-benzoyl chloride were added.

G of sodium carbonate were then added in small portions, the internal temperature being kept between 5° and 10°C.

The suspension was agitated for 2 hours at ambient temperature, poured into 800 cc. of iced water, and extracted three times with 1 litre of methylene chloride and once with 500 cc. of methylene chloride. The organic phase was then washed with salt water, dried over magnesium sulphate and evaporated to dryness.

G of crude product were thus obtained, and redissolved in 350 cc. of chloroform at reflux. The resultant solution was filtered, concentrated and left to crystallise.

After recrystallisation from dioxane, 4.4 g of N-[2-(4~ (1, 3-dihydro-2-oxo-l-(2H)-benzimidazolyl)-1-piperidinyl)-ethylj-4fluorobenzamide were recovered, in the form of a colourless solid melting at 242°C.

Analysis: C 21Η23Ρ!^4θ2 = 38^.446 Calculated: C% = 65.95 H% = 6.06 FiS = 4.97 NiS = 14.65 Determined : 65.7 6.0 4.8 14.3 The 4-0,3-dihydro-2-oxo-l-(2H)-benzimidazolylJ-l-piperidineethaneamine dihydrobromide used as starting material in Example 1 above was prepared as follows: Preliminary Stage A: Preparation of 2-0-(4-(1,3-dihydro-2-oxol-(2H)-benzimidazolyl )-1 -piperidinyl )-ethylJ~ jlHj-isoindol-1,3, [2h]-dione.

G of 4-0,3-dihydro-2-oxo-l-(2H)-benzimidazolylj-piperidine and 23.6 g of N-bromoethylphthalimide were dissolved in 400 cc. of dimethylformamide. The solution was heated to 120°C, and 8.4 g of sodium carbonate were added.

The resultant suspension was agitated for 45 minutes at 120°C, poured into 500 cc. of water and ice, and extracted with methylene n 4 2 9 3 chloride. Then the organic phase was washed with water, dried over magnesium sulphate and evaporated to dryness.

G of crude product were thus obtained, and dissolved with heating in A litres of methyl ethyl ketone. The resultant solution was filtered, concentrated and left to crystallise.

After drying, 20.5 g of 2-[2-(4-(l,3-dihydro-2-oxo-l-(2H)benzimidazolyl )-l-piperidinyl)-ethylj-[jHj-isoindole-l ,3 y2Hj-dione were recovered, in the form of a pale yellow solid, melting at 220°C.

Analysis: Calculated Determined C22H22N403 = 390.448 = 67.67 H% = 5.68 = 14.35 67.4 5.7 14.1 Preliminary Stage B: Preparation of 4-Q,3-dihydro-2-oxo-l-(2H)benzimi dazolyl] -1-pi peri di ne-ethananrine di hydrobromide.

G of 2-^2-(4-(1,3-dihydro-2-oxo-l-(2H)-benzimidazolylj-l15 piperidinyl)-ethyfJ-[lH]-isoindole-l,3[2H]-dione were dissolved in cc. of 48% hydrobromic acid and 43 cc. of acetic acid The solution was taken to 100°C, and this temperature was maintained for 16 hours; the solution was then allowed to cool to about 50°C, and the hydrobromic acid and the acetic acid were evaporated off under vacuum. The residue was cooled on an ice-bath, and drop by drop 35 cc. of methanol were added. The whole was then left to crystallise, filtered off and rinsed with methanol, then with diethyl ether.

After drying under vacuum at ambient temperature, 20 g of λ Oj k-iO ,3-dihydro-2-oxo-l-(2H}-berziinidazolylj“i-piperidine-ethananrine dihydrobromide were recovered, in tbs form of beige crystals melting at 239°C.

EXAMPLE 2: Preparation of N-f2-(4-(1,3-dihydro-2-o/o-l-(2H)-benzimidazolyl) -2-?iperidinyl}-ethy1j-4-f1uorober,zaraide neutral oxalate.

To a solution of 5.04 g of N-jj!-(4-(] ,3-dihydro-2-oxo-i-(2H;benzimidazolyl)-1-piperidinyl)-ethyl·-4-fluorobenzamide in 500 cc. of methanol there was added a solution of 1.65 g Of Oxalic acid dihydr? in 15 cc. of methanol. The mixture was then concentrated under vacuum at 40°C, and 4.8 g of the crude product thus obtained was filtered off.

This crude product was tnen redissolved in ethanol at reflux, concentrated, ice-cooled, filtered and rinsed with iced ethanol.

G of[N- 2-(4-(1,3-dihydro-2-oxo-l-(2H)-benzimidazolyl-l15 piperidinyl)-eihylj -4-fluorobenzamide neutral oxalate were recovered, in the form of a colourless product melting at 250°C.

Analysis: Ο^Η^θΕ,ΝθΟβ = 854.904 Calculated: Ci = 61.71 HZ = 5.66 NS = 13.1 r% = 4.40 Determined: 61.5 5.8 12.9 4.7 EXAMPLE 3: Preparation of Μ-Γ2-(4-(1,3-dihydro-2-oxo-l-(2H)-benzimidazolyl) 1-pi peri dinyl)-ethylj -4-fluorobenzaaide hydrochloride.

G of N-[2-(4-(l,3-dihydro-2-oxo-1-(2H)-benzimidazolyl)-1piperidinyl}-ethylj-4-f1uorobenzamide (obtained as described in Example 1) were suspended in 20 cc. of water, and 25 cc. of 2N-hydrechloric acid were added under agitation. The mixture was allowed to react for 30 minutes, and then filtered.

After filtration, 13.4 g of crude hydrochloride were recovered, and redissolved in 200 cc. of isopropanol containing 102 of water.

The resultant solution was concentrated to 70 cc., and left to crystallise in the refrigerator. The desired product was then filtered off, and rinsed with Isopropanol and with diethyl ether.

G of N-[2-(4-(l,3-dihydro-2-oxo-l-(2H)-benzimidazoly1)-1piperidinyl)-ethylj-4-fluorobenzamide hydrochloride were thus recovered, in the form of colourless crystals. M.Pt. = 245-247°C.

Analysis: C2lH24C1™402 = 418.911 Calculated: C% = 60.21 H% = 5.77 CIS = 8.46 F5£ = 4.54 ΓΚί = 13 Determined: 59.9 5.8 8.2 4.2 13.

EXAMPLE 4: Preparation of Tablets for Oral Administrations.

Tablets were made up, corresponding to the formula: N-02-(4-(1,3-di hydro-2-oxo-l-(2H)-benzimi dazolyl) -l-piperidinyl)-ethy] -4-fluorobenzamide hydrochloride Excipient, q.s. for one tablet up to mg: 100 mg.

[Note: the excipient consisted of lactose, starch, talc and magnesium stearate] 2 9 3 EXAMPLE 5: Preparation of Solution for Injection.

An injectable solution was prepared, of formula: N-j_2-(4-(l,3-dihydro-2-oxo-l-(2H)-benzimidazolyl)-15 piperidinyl)-ethyi]-4-fluorobenzamide hydrochloride 10 mg.

Aqueous excipient q.s.v. 2 ccs.

It was made ready for injection by sterilisation in the conventional manner.

Claims

1. The N-substituted benzamide derivatives conforming to the general formula: (I) R 5 (in which R represents a hydrogen atom or an alkyl radical containing from 1 to 3 carbon atoms, £ is 2 or 3, and X represents a hydrogen, fluorine, chlorine or bromine atom, or a methoxy, tri fluoro-methyl, nitro or amino radical) and the acid addition salts thereof.

2. The N-substituted benzamide derivatives claimed in claim 1, which 10 conform to general formula I in which R represents a hydrogen atom, _n is 2 or 3 and X represents a fluorine atom, and their acid addition salts.

3. Ν-[2-(4-(1,3-Di hydro-2-oxo-l-(2H)-benzimidazolyl)-1-piperidinyl)ethyfj-4-f 1 uorobenzamide and its acid addition salts.

4. The acid addition salts claimed in any of the preceding claims, when formed with hydrochloric, hydrobromic, hydroidic, nitric, 5. Sulphuric, phosphoric, acetic, formic, benzoic, maleic, fumaric, succinic, tartaric, citric, oxalic, glyoxylic or aspartic acid, or with any alkanesulphonic or arylsulphonic acid.

5. N-[2-(4-(1,3-Dihydro-2-oxo-l-(2N)-benzimidazolyl)-1-piperidinyl) -ethyl] -4-f1uorobenzamide hydrochloride. 10

6. · A process for preparing the N-substituted benzamide derivatives including acid addition salts thereof as claimed in claim 1, in which a starting material of general formula: (in which R and ji have the meanings defined in claim 1) is reacted with a benzoyl halide derivative of general formula A —CO X (in which A represents a halogen atom and X has the meaning 5 defined in claim 1) to yield the desired N-substituted benzamide in the form of a free base, and if desired the latter is then reacted with a mineral or organic acid to form the corresponding acid addition salt thereof.

7. A process as claimed in claim 6 and substantially as herein 10 described.

8. A process as claimed in claim 6 or claim 7, in which the starting material of general formula II is first prepared by reacting a compound conforming to the general formula: 44393 (in which R has the meaning defined in claim 1) with a halide of formula: 5 (in which Hal represents a chlorine or bromine atom, and £ bas the meaning defined in claim 1) to form a product of general formula: *44293 ζ Ν Ν~ ( C H 2 )—Ν Ο (VI) (in which R and ji have the previously-indicated meanings) and the latter is subjected to the action of hydrobromic acid in an acetic acid medium to form the hydrobromide of the desired compound of general 5 formula II, which is then rendered alkaline to yield the unsalified starting material aforesaid.

9. A process as claimed in claim 8 and substantially as herein described.

10. The N-substituted benzamides of general formula I and their 10 acid addition salts whenever prepared by the processes claimed in any of claims 6 to 10.

11. Pharmaceutical compositions which contain one or more of the N-substituted benzamides of general formula I and/or their acid addition salts formed with pharmacologically-acceptable acids as claimed 15 in any of claims 1 to 5 or 10, in association with a pharmaceutical vehicle. 4 4 393

12. Compositions as claimed in claim 11 wherein the N-substituted benzamide(s) of general formula I and their acid addition salts are those in which R represents a hydrogen atom, £ is 2 or 3 and X represents a fluorine atom.

13. Compositions as claimed in claim 11 or claim 12 wherein the N-substituted benzamide is N-jj2-(4-(l ,3-dihydro-2-oxo-l-(2H)benzimidazolyl)-l-pi'peridinyl)-ethyl]-4-fluorobenzamide and/or its hydrochloride.

14. Compositions as claimed in any of claims 11 to 13 in which the 10 pharmaceutical vehicle is the ingestible excipient of a tablet, or pill, the ingestible container of a capsule or cachet, the ingestible pulverulent solid carrier of a powder, or the ingestible liquid medium of a syrup, solution, suspension or elixir.

15. Compositions as claimed in any of claims 11 to 13 in which the 15 pharmaceutical vehicle is a sterile, injectable liquid solution or suspension medium.

16. Compositions as claimed in any of claims 11 to 13 in which the pharmaceutical vehicle is base material of low melting point capable of releasing the active ingredient to perform its pharmacological function, 20 which base material when appropriately shaped forms a suppository.

17. Compositions as claimed in any of claims 11 to 16 and substantially as herein described.