GB2148280A

GB2148280A - Pyridinium compounds

Info

Publication number: GB2148280A
Application number: GB08422460A
Authority: GB
Inventors: John Terence Arnott Boyle
Original assignee: John Wyeth and Brother Ltd
Current assignee: John Wyeth and Brother Ltd
Priority date: 1983-09-07
Filing date: 1984-09-05
Publication date: 1985-05-30
Also published as: ES535704A0; PT79177A; GB2148280B; KR850002253A; GB8323949D0; FI843390A0; PH20851A; IL72819A; GR80222B; FI843390A; GB8422460D0; US4608379A; AU3250184A; CA1239644A; AU570718B2; IL72819A0; DK426484D0; JPS60155157A; EP0139440A2; ZA846590B

Description

1 GB 2 148 280 A 1

SPECIFICATION

Pyridinium compounds This invention relates to pyridiniurn compounds for use as anti-fungal agents. Some of the pyriclinium 5 compounds are novel perse. The invention also relates to a process of making the compounds and pharmaceutical compositions containing them.

The condensation between 4-dimethylaminobenzalclehyde and 1,2dimethylpyridinium iodide was investigated by Mills and Pope [J. Chem. Soc., 121,946 (1922)]. The product, 2-[4-(dimethylamino)styryll-l methylpyriclinium iodide (hereinafter called compound A), was found to have a powerful sensitising action 10 for green light upon the photographic plate. Condensation of the same alclehyde (4-dimethylamino benzalclehyde) with 1,4-dimethylpyridinium iodide was investigated by Clemo and Swan [J. Chem. Soc., 1938, page 14541. The condensation product, 4-[4-(dimethylamino)styryll-1 -methylpyriclinium iodide, is hereinafter called compound B. The 3-position isomer of compounds A and B, 3-[4-(dimethylamino)styryl]-l- methyI iodide, has been reported in the literature [J. Indian Chem. Soc., 24,301-6 (1947)]. However, an attempt by the inventor to repeat the reported synthesis of the compound by treating 1,3- dimethylpyridinium iodide with 4 dimethylaminobenzaldehyde in refluxing ethanol with pipericline as catalyst failed to secure the reported product. The alclehyde was recovered unchanged. It is believed that the methyl group at the 3-position of -the starting pyriclinium compound is insufficiently activated to undergo the condensation.

A number of compounds related to compounds A and B have been disclosed in the literature. They include 2-14-(dimethylamino)styryl]-5-ethyl-l-methylpyridinium iodide [see J. Org. Chem., 28,388 (1963)1; 2-[4-(diethylamino)styryll-l-methylpyridinium iodide (hereinafter referredto as compound Q [J. Org.

Chem., 12,333 (1947)1; 244-(d i m ethyl am i no)styryl 1-1 -(iso-pro pyl, sec-butyl, iso-butyl or iso-amyl) pyridi nium iodide [Chem. Abs., 41,3102c (1947)1; 2-[4-(dimethylamino)styryll-1 - (ethyl, propyl or butyl) pyriclinium 25 iodide [Chem. Abs., 36,6926 6 (1942)1; 2-[4-(diethylamino)styryll-1 - (ethyl, propyl or butyl) pyridinium iodide [Chem. Abs., 37,42496 (1943) 1; 2- or 4-[4-(diethylamino)styryl-1 -n-hexylpyridinium bromide and 2- or 4- [4-(di-n-hexyIamino)styryI1-1 -n hexylpyridinium bromide [U.S Patent 2,686,7841; 2-[4(dimethylamino)styryll-1 -(dodecyl or octaclecyl) pyridinium bromide [U.S. Patent 2,255,077]; and 4-[4-(di methylamino)styryl]-l -ethyl pyridiniu m iodide 30 (hereinafter referred to as compound D) [Chem. Abs., 40,15195 (1946)).

The compounds designated as compounds A, B, C and D above have been reported to show inhibition of the fungus Neurospora crassa (wild type 4A) in Ann. N.Y. Acad. Sci., 76, 413-441 (1958) at page 440.

However, when tested against other fungi these compounds may show no or little anti-fungal activity. In particular, our own results have found that compound A is not active against Cryptococcus neoformans (ATCC 14115). Moreover, compound B has been reported as inactive against Epidermophyton rubrum, Microsporum lanosum and Trichophyton gypseum in Mikrobiol. Zh. Akad. Nauk, Ukr, SSR., 25(5j, 58-67 (1963). The four pyriclinium compounds tested in the Ann. N.Y. Acad. Sci. reference have the characteristic that the substituent at the 1 -position of the pyridine ring is methyl or ethyl. It has now been found tht the potency against one or more fungi can be improved by using a substituent containing 3 or more carbon atoms at this position as is illustrated in Tables 1, 2 and 3 below.

The invention provides pyriclinium compounds for use as pharamceuticals, particularly as anti-fungal agents. The pyriclinium compounds are those containing a cation having the formula la or lb 45 R 22 (1a) N CR -CR4--&NR6R7 p:5- - R1 or 50 2 _5 4 (Ib) 4 R, -N/ CR =CR4--NR R 3 6 7 55 and a pharmaceutically acceptable anion. In formulae la and lb R, represents alkyl containing at least 3 carbon atoms or aralkyl; R2 and R5 are independently hydrogen, lower alkyl, lower alkoxy, halogen or nitro; R3 and R4 are independently hydrogen or lower alkyl; and R6 and R7 are independently lower alkyl or aryl 60 (lower) alkyl or R6 and R7, when joined together, represent a group having the formula 11 -(CH2)2-A-(CH2)2(11) (where A is -(CH2)n-, 0, S or NR8 where n is 0, 1 or 2 and R8 is lower alkyl) or a mono or di-(Iower alkyl) 65 2 GB 2 148 280 A 2 substitution product thereof.

The term---lower-herein as applied to alkyi or alkoxy means that the alkyl or alkoxy group contains 1 to 6 carbon atoms, preferably 1 to 4 carbon atoms. As examples, there may be mentioned methyl, ethyl, propyi, isopropyl, butyl, pentyl and hexyl and methoxy, ethoxy, propoxy, isopropoxy, butoxy, pentoxy and hexoxy.

The term "aryl (lower) alkyi" herein means lower alkyl (as defined above) monosubstituted by an aryl group, preferably a phenyl group. As examples benzyf and phenethyl may be mentioned.

The cations of formulae]a and lb are position isomers. The 4-position isomer, i.e. the cation of formula lb, is preferred.

R, may be an alkyl group containing at least 3 carbon atoms, preferably 3 to 20 carbon atoms, for instance, propyl, isopropyl, buty], pentyl, hexyi, heptyl, octyi, nony], decyl, undecyl, dodecyi, tetradecyl, hexadecy], 10 octadecyl and eicosyl. The alkyl group advantageously contains 3 to 12 carbon atoms. R, may also be arylalkyl, preferably aryl (lower) alkyl, advantageously benzyi or phenethyl. R3 and 24 are preferably hydrogen or methyl, advantageously hydrogen. R2 and R5 are independently hydrogen, lower alkyl or alkoxy (for instance as illustrated above), halogen (for instance chlorine or bromine) or nitro. R6 and R7, when separate, may be lower alkyl (for instance as illustrated above) or aryl (lower) alkyl, preferably phen (lower) 15 alkyl, advantageously benzy] or phenethy]. R6 and R7, when separate, are most advantageously methyi or ethyl. R6 and R7 may be joined so that -NR6R7 represents pyrrolidino, piperidino, morpholino, thiomorpholino, 4-loweralkylpiperazin-l-yi, preferably piperidino. The ring carbon atoms are optionally substituted by a total of up to two lower alkyl groups.

As examples of the pharmaceutically acceptable anion of the anti-fungal compound there may be 20 mentioned a halide (for instance, chloride, bromide or iodide), sulphate, nitrate, phosphate, an organosul phonate (for instance methane-su 1 phonate or p-tol uenesul phonate), acetate, maleate, citrate, fumarate, tartrate, malonate, or formate.

Some of the anti-fungal compounds of the invention are known perse. However, it is believed that none of the known compounds has been previously known for any therapeutic purpose.

The anti-fungal compounds that are novel perse include those containing a pharmaceutically acceptable anion and the cation of formula]a or lb where R,, R2, R3 R4, R5, R6 and R7 are as defined above subject to the proviso that, if both R6 and R7 are lower alkyl, then R2, R4 and R5 are not all hydrogen. The novel compounds of this invention especially include those where R2 is lower alkyl and also those where R6 and R7 together represent formula 11 or a mono- or di- (lower alkyl) substitution product thereof.

The anti-fungal compounds of the invention are prepared by condensing a pyridinium compound containing a cation having the formula Ilia or [lib R or 2 35 % CH 2 R 3. R, - N // C R 3 1 Ri (Ilia) (111b) 40 (where R,, R2 and R3 are as defined above) with a carbonyl compound having the formula IV 5 45 0 =c \ A NR 6 R7 1-6- R& (IV) (where R4, R5, R6 and R7 are as defined above) or a reactive derivative of such a carbonyl compound. The condensation of the carbonyl compound with the compound containing the cation of formula Illa or Illb may be carried out in known manner, normally in the presence of a catalyst such as piperidine. Alternatively the condensation may be carried out with a reactive derivative of the carbonyl compound, for instance an imine having the formula V1 CS Rg-N=C-&NP6R7 60 1 H4 (V1) (where R4, R5, R6 and R7 are as defined above and R9 is hydrogen or lower alkyl). The use of an imine is 3 GB 2 148 280 A 3 recommended particularly where R4 is lower alkyl.

The anion of the compound containing the cation Ilia or Illb is preferably the same as the pharmaceutically acceptable cation in the anti- fungal compound of the invention. Alternatively, the pharmaceutically acceptable anion may be incorporated by exchange of anions in known manner, as a subsequent step.

The anti-fungal compounds of the invention may be tested for activity by means of the following in vitro procedure.

Test substance is solubilised or suspended in appropriate reagent and further diluted in sterile distilled water to provide a range of concentrations from 200 to 10 I.Lg/ml. 20 lambda portions are placed on sterile dried 1/4" paper discs and allowed to dry for 20-30 minutes. Agar plates with a 10ml base layer are seeded with the fungi in a 4ml seed layer and allowed to solidify. The impregnated discs are then placed on the seeded agar surface and incubated for the time required for the particular culture.

The representative fungi are:

Candida albicans Cryptococcus neoformans Histoplasma capsulatum Blastomyces dermatitidis ATCC 10231 (CA) ATCC 14115 (CN) ATCC 11407 -yeast phase (HC) ATCC 28839 - Yeast phase (BD) Trichophyton mentagrophytes ATCC 9533 (TIVI) 20 The letters in brackets represent an abbreviation used for identification in the Tables of results below. All five fungi are human pathogens; the first four cause serious systemic mycotic infections as well as local. The trychophyton culture is mainly a dermatophyte. Clotrimazole may be used as a control. Activity is indicated by size in mm. of any zones exhibited by the compounds. A compound is regarded as inactive where no zone is exhibited at the highest concentration tested (200 [tg/mi).

Table 1 below illustrates the effect of increasing the number of carbon atoms in the alkyl group at the 1 position of the pyridine ring of 1 alkyl-2-[4-(dimethylamino)styryI pyridinium compounds of the formula VII CC),-CH=CH N p X E) Ri (VII) TABLE 1

Compound Compound A Compound of Compound of Example3 Example 5 Meanings of R, methyl hexyl dodecyl Symbols in 45 Formula V11 X8 iodide bromide bromide Illustrating invention or for Comparison Invention Invention 50 comparison l 'I mm at 10.8mm at 1Omm at Fungus CA 200 Lg/mi 200 lig/m 1 100 Kg/m 1 55 No 26mm at 9mm at Tested CN activity 100 [Lg/m 1 10 l.Lg/m 1 1Omm at 16.3mm at 8mrn at and TIVII 200 i.Lg/m 1 100 L9/M 1 100 [Lg/m 1 60 4 GB 2 148 280 A 4 TABLE 1 (Continued) Compound CompoundA Compound of Compound of Example3 Example 5 5 8mm at 15.3mm at 12.3mm at Results HC 100 Rg/m 1 100 gg/m 1 10 Lg/m 1 13mm at 13mm at 8mm at BD 100 11g/m 1 10 Rg/M1 10 Kg/M11 0 Table 1 shows thatthe 1-hexyl compound of the invention demonstrated anti- fungal activity atthe same concentration as the 1-methyl comparison compound in the case of two fungi and at a lower concentration in the case of the otherthree fungi. The 1-clodecyl compound of the invention demonstrated an anti-fungal response at a lower concentration than the 1-methyl comparison compound in the case of all five fungi tested. Thus the increase in the number of carbon atoms in the 1-alkyl substituent tends to improve activity. Table 2 below compares two 1-alkyl- 2-(4-diethylaminostyryl)pyridinium compounds of the formula VIII CIZ-1 C,-CH=CH _(YN(C2H 5)2 Ne (D 1 X K (Vill) 25 TABLE 2

Compound Compound C Example4 30 Meaning of the R, symbols in formula Vill methyl X- iodide hexyl bromide 10.3mm at 12mm at Fungus CA 200 Kg/mf 100 [Lg/M1 1Omm at 14m m at Tested CN 100 Lg/m 1 10 iiglml 40 1Omm at 13mm at and TM 100 119/M 1 10 [úg1M 1 1Omm at 14m m at 45 Results HC 100 Kg/M1 logg/M1 9mm at 14m m at BD 10 K91M1 10 1Lg/m 1 50 Table 2 shows that the 1-hexyl compound of the invention showed an anti- fungal response atthe same concentration as the 1-methyl comparison compound in the case of one fungus (BD) but exhibited activity at a lower concentration than the 1-methyl comparison compound in the case of the otherfourfungi. Again the increase in the number of carbon atoms in the 1-alkyl group tends to improve potency.

GB 2 148 280 A 5 Table 3 below compares 1-propyl and 1-ethyl compounds having the formula]X C H 2 \\-N(CHh 5'C, -CH=CH N exe 1 R 1 OX) TABLE 3

Compound Comparison Invention 15 (invention or Comparison) (Example 2) Meanings of symbols R, ethyl propyl in formula IX XE) iodide bromide 20 No 1Omm at Fungus CA activity 100 Kg/m 1 18.3mrn at l 'I mm at 25 Tested CN 100 11g/M 1 100 Lg/m 1 No 11.7mm at and TM activity 100 [jg/m 1 9.5mm at 16.3mrn at Results HC 100 Kg/m 1 10 K91m] I 'I mm at 14.3mm at BD 100 tig/m l 10 Kg/M1 35 In the case of fungus CN, the two compounds both exhibited a zone at the same concentration. In the case of the otherfourfungi, the 1-propyl compound exhibited zones at a lower concentration than the 1-ethyl compound.

Table 4 below presents results for other anti-fungal compounds of this invention.

TABLE 4

Compound Fungus obtained in Example No.

CA CN TM I-IC BD 1 12mrn at 23.3mm at 19.3mrn at 15mrn at 12.7mm at 50 K91M 1 100 [lg/m 1 100 [úg1M 1 10 gg/mi 10 iig/m] 6 9mm at 9.3mrn at 9mm at 9mrn at 9mrn at 100 gg/m] 100 Kg/m 1 200 gg/m l 10 fig/m 1 100 lig/m 1 55 7 9mm at 12mrn at 9mm at 11.3mm at 7mm at pg/m 1 100 Lg/m 1 100 119/M 1 100 Itg/m 1 10 Lg/m 1 6 GB 2 148 280 A TABLE 4 (Continued) 6 Compound Fungus obtained in Example No. 5

CA CN TM HC BD 8 12.3m m at 18mm at 23.3mrn at 10.3mm at 9mm at llg/m 1 100 [Lg/m 1 100 119/M1 10 gg/m] 10 gg/mi 10 9 8mm at 8.7mm at 8mm at 12mrn at NOT [lg/m 1 100 11g/m 1 10 [Lg/m 1 10 Kg/M1 TESTED 1Omm at 17.7mm at 1Omm at 26mm at NOT 10 lig/m 1 10 gg/m] 10 K91M1 10 [lg/M1 TESTED 15 11 15.3mm at 25.3mm at 23mm at 35mm at NOT Kg/M1 10 fig/m 1 10 Lg/m 1 10 Kg/M1 TESTED 20 The antifungal compounds of this invention may be administered internally (for instance orally) or topically in the form of compositions containing the compound in association with a pharmaceutically acceptable carrier. Any suitable carrier known in the art can be used to prepare the pharmaceutical compositons. In such a composition, the carrier may be a solid, liquid or mixture of a solid and a liquid. Solid form compositions include powders, tablets and capsules. A solid carrier can be one or more substances which may also act as flavouring agents, lubricants, solubilisers, suspending agents, binders or tablet-disinteg rating agents; it can also be an encapsulating material. In powders the carrier is a finely divided solid which is in admixture with the finely divided active ingredient. In tablets the active ingredient is mixed with a carrier having the necessary binding properties in suitable porportions and compacted in the shape and size desired. The powders and tablets preferably contain from 5 to 99, preferably 10-80% of the active ingredient. Suitable solid carriers are magnesium carbonate, magnesium stearate, talc, lactose, pectin, dextrin, starch, gelatin, tragacanth, methylcellulose, sodium carboxymethyl cellulose, a low melting wax, and cocoa butter. The term "composition" is intended to include the formulation of an active ingredient with encapsulating material as carrier to give a capsule in which the active ingredient (with or without other carriers) is surrounded by the carrier, which is thus in association with it. Similarly cachets are included.

Sterile liquid form compositions include sterile solutions, suspensions, emulsions, syrups and elixirs. The active ingredients can be dissolved or suspended in a pharmaceutically acceptable sterile liquid carrier, such as sterile water, sterile organic solvent or a mixture of both. Preferably a liquid carrier is one suitable for parenteral injection. Where the active ingredient is sufficiently soluble it can be dissolved in normal saline as a carrier; if it is too insoluble for this it can often be dissolved in a suitable oranic solvent, for instance 40 aqueous propylene glycol or polyethylene glycol solutions. Aqueous propylene glycol containing from 10 to 75% of the glycol by weight is generally suitable. In other instances other compositions can be made by dispersing the finely-divided active ingredient in aqueous starch or sodium carboxymethyl cellulose solution, or in a suitable oil, for instance arachis oil. Liquid pharmaceutical compositions which are sterile solutions or suspensions can be utilised by intramuscular, intraperitoneal or subcutaneous injection. In many instances a compound is orally active and can be administered orally either in liquid or solid composition form.

Preferably the pharmaceutical composition is in unit dosage form, e.g. as tablets or capsules. In such form the composition is sub-divided in unit doses containing appropriate quantities of the active ingredients; the unit dosage form can be packaged compositions, for example packeted powders or vials or ampoules. The 50 unit dosage form can be a capsule, cachet or tablet itself, or it can be the appropriate number of any of these in package form. The quantity of the active ingredient in a unit dose of composition may be varied or adjusted from 5 mg. or less to 500 mg. or more, according to the particular need and the activity of the active ingredient. The invention also includes the compounds in the absence of the carrier where the compounds are in unit dosage form.

Where the antifungal compound of the invention is to be administered topically it may be presented in the form of an aerosol, a semi-solid pharmaceutical composition, a powder or a solution. By the term "a semi-solid composition" there is meant an ointment, cream, salve, jelly or other pharmaceutical composition of substantially similar consistency suitable for application to the skin. Examples of semi-solid compositions are given in Chapter 17 of The Theory and Practice of Industrial Pharmacy, Lachman, 60 Lieberman and Kanig, published by Lea and Febiger (1970) and in Chapter 67 of Remington's Pharmaceutical Sciences, 15th Edition (1975) published by Mack Publishing Company.

Preferably, the topical compositions of the present invention contain from about 0.1% to about 20% by weight of the active ingredient. The compositions may, for example, contain from about 0.5% (preferably from about 1 %) to about 10% by weight of the active ingredient.

7 GB 2 148 280 A 7 The carrier used in the topical compositions of the present invention may be any carrier suitable for preparing topical semi-solid compositions or topical aerosol compositions. Examples of suitable carriers for semi-solid compositions are given in Lachman, Lieberman and Kanig (loc- cit) and in Chapter 67 of Remington's Pharmaceutical Sciences, (lot-cit). The carrier for the semi- solid composition may be, for example, an emulsion base of the oil in water class (e.g. an emulsion of soft and liquid paraffins in water). 5 Alternatively, the carrier may be an absorption base (e.g. a mixture of wool fat and soft paraffin). A third class of suitable carriers are water miscible bases (e.g. mixtures of high and low molecular weight polyethylene glycols).

When the composition is in aerosol form for topical administration, the composition may comprise the active ingredient and an easily liquifiable gas. Examples of such liquifiable gases are halogenated hydrocarbons and liquified lower hydrocarbons, both of which are well known as propellants in the aerosol art. (By 1ower hydrocarbon" is meant a hydrocarbon containing up to six carbon atoms).

In addition to the active ingredient and the carrier base, the topical compositions of the invention may contain other ingredients such as antioxidants, buffers, emulsifying agents, perfumes, preservatives and solvents which confer on the product properties desirable in a topical formulation.

As an example of a solution for topical administration there may be mentioned tinctures, in particular solutions of the active ingredient in alcohol or aqueous alcohol at concentrations of, for instance, 0.1 % - 1%.

The following Examples illustrate the preparation of antifungal compounds of this invention.

Example 1

2[4-(Diethylamino)styryll-5-ethyl- 1-propylpyridinium salt 5-Ethyl -2-m ethyl- 1-propylpyridinium bromide (7.32g, 0.03 mole) and 4diethylaminobenzaldehyde (7.0g, 0.04 mole) were refluxed forfour hours in methanol (50mi) in the presence of piperidine (lmi) under nitrogen. On cooling and addition of ether no precipitate was obtained. The solution was evaporated to give a red oil which was dissolved in isopropanol and twice the volume of ether was added, when a red crystalline 25 solid was obtained (5.4g). 2 Grams were re-dissolved in isopropanol and isopropyl ether was added to give red crystals of 2-[4-(diethylamino)styryll-5-ethyl-l-propylpyridinium bromide hernihydrate (1.6g), melting point 165-1670 (decomposition).

Analysis 30 Found: C, 63.9%; H, 7.77%; N, 6.44%.

C22H3,BrN2.1/2H20 requires C, 64.1 %; H, 7.82%; N, 6.79%.

35 Example 2

2-[4-(Dimethylamino)styryll-5-ethyl- 1-propylpyridinium salt 5-Ethy]-2-methyl-l -propyl pyridi niu m brom ide (8.19, 0.033 mole) and 4di methylam inobenzal dehyde (6.0g, 0.04 mole) were ref luxed in metha nol (50m 1) i n the presence of pi peridine (1.5m 1) u nder n itrogen for fou r hours. Ether was added to the cool solution and, on scratching, a red solid crystallised which was collected 40 and washed with a little isopropanol to give 2-[4-(dimethylamino)-styryll- 5-ethyi-1 -propylpyridinium bromide (7.7g). Melting point 236-237' (decomposition).

Analysis Found: C201-127BrN2 requires C, 63.9%; H, 7.50%; N, 7.33%.

C, 64.0%; H, 7.25%; N, 7.46%.

Example 3

2-[4-(Dimethylamino)styryll- 1hexylpyridinium salt 1-Hexyi-2-methylpyridiiiium bromide (7.8g, 0.03 mole) and 4dimethylaminobenzaidehyde (6.0g, 0.04 mole) were refluxed in methanol (50mi) in the presence of piperidine (1. Omi) under nitrogen for four hours.

On cooling and the addition of about 1 00mf of ether a solid crystallised which was collected and washed with a little isopropanol to give 2-[4-(dimethylamino)styryll-1 - hexylpyridinium bromide (6.3g), melting point 55 217-218' (decomposition).

Analysis Found: C, 64.6%; H, 7.51 %; N, 7.15%. 60 C21]-129Bri\12 requires C, 64.8%; H, 7.51 %; N, 7.19%.

8 GB 2 148 280 A 8 Example 4

2-[4-(Dieth y1aminojstyry1j- 1-hexylp yridinium saft 1 -Hexyl-2-methylpyridinium bromide (7.8g, 0.03 mole) and 4diethylaminobenzaidehyde (7.0g, 0.04 mole) were refluxed in methanol (50ml) in the presence of piperidine (1.0ml) under nitrogen for four hours. The solution was evaporated and the resulting oil was redissolved in a small amount of isopropanol. Addition of 5 twice the volume of ether gave a red crystalline solid which was collected and washed with isopropanol/ ether to give 2-[4-(diethylamino)styryll-1 -hexylpyridinium bromide hemillydrate (5.8g), melting point 222-223' (decomposition).

Analysis 10 Found: C, 65.0%; H, 7.73%; N, 6.46%.

C23H33BrN.1/2H20 requires C, 64.8%; H, 8.04%; N, 6.57%.

Example 5 2-[4-(dimethylamino)styryl- 1-dodecylp yridinium salt 1-Dodecyl-2-methylr)yridinium bromide (3.429, 0.01 mole) and 4dimethylaminobenzaidehyde (1.69, 0.011 mole) were refluxed in ethanol (15mi) in the presence of piperidine (0.2mi) under nitrogen fortwo hours. The 20 solution was cooled and ether was added when an orange solid crystallised which was collected giving 2-[4-(clim ethyl am in o)styryl 11 -dodecylpyridinium bromide quarter hydrate (2.4g), melting point 197198'C.

Analysis Found: C, 67.7%; H, 8.97%; N, 5.85%. 25 C27H4,BrN2.1/4H20 requires C, 67.8%; H, 8.75%; N, 5.86%.

Example 6 30 2-[4-(Diethylamino)styryll- l-dodecylpyridinium salt 1 -Dodecyi-2-methylpyridinium bromide (3.42g, 0.01 mole) and 4diethylaminobenzaidehyde (1.9g), 0.011 mole) were refluxed in ethanol (1 5mi) in the presence of piperidine (0.2mi) under nitrogen for two hours. The solution was cooled and ether was added when an orange solid crystallised which was collected giving 2-[4-(diethylamino)styryll-ldodecylpyridinium bromide hemihydrate, (2.1g), melting point 199-200'C.

Analysis Found: C29H45Bri\12.1/2F120 requires C, 68.4%; H, 9.13%; N, 5.35%.

C, 68.2%; H, 9.08%; N, 5.4%.

Example 7

1-Benzyl-2-[4-(dimethylamino)styryllpyridinium salt 2-Picoline (9.3g, 0.1 mole) and benzy] bromide (17.1g, 0.1 mole) were refluxed in isopropanol (50mi) overnight. The solventwas evaporated giving an oil which was heated at 1OWC for six hours. The resulting 45 crude oil (8.0g, 0.03 mole) and 4-dimethylaminobenzaidehyde (4.6g, 0.03 mole) were refluxed in methanol (50mi) in the presence of piperidine (0.2mi) under nitrogen forthree hours. On cooling dark-coloured crystals were obtained which were collected to give 1 -benzyl-2-[4-(di methyl am in o)styryll pyridi n i u m bromide (6.8g), melting point 250-251'C.

Analysis Found: C22H23Bri\12 requires C, 66.9%; H, 5.99%; N, 6.77%.

C, 66.8%; H, 5.86%; N, 7.09%.

Example 8

1-Benzyl-2-[4-(diethylamino)styryllpyridinium salt 2-Picoline (9.3g, 0.1 mole) and benzyl bromide (17.1g, 0.1 mole) were refluxed in isopropanol (50mi) overnight. The solvent was evaporated giving an oil which was heated at 1000C for six hours. The resulting 60 crude oil (8.5g, 0.032 mole) and 4-diethylaminobenzaidehyde (6.09, 0.033 mole) were refluxed in methanol (40mi) in the presence of piperidine (0.2mi) under nitrogen forthree hours. On cooling dark-coioured crystals were obtained which were collected to give 1-benzyi-2-[4- (diethylamino)styryllpyridinium bromide (6.2g), melting point 231-2330C.

9 GB 2 148 280 A 9 Analysis Found: C24H27BrN2 requires C, 67.8%; H, 6.41 %; N, 6.38%.

C, 68.1 %; H, 6.43%; N, 6.62%.

Example 9 1-Dodecyl-2-[(4-piperidino)styryllpyridinium salt 1-Dodecyl-2methylpyridinium bromide (2.3g, 0.0067 mole) and 4-piperidinobenzaldehyde (1.27g, 0.0067 mole) were refluxed in methanol (20mi) in the presence of piperidine (0.1 mi) under nitrogen for three hours.10 The solution was cooled and addition of ether gave a crystalline solid which was collected giving 1-dodecyi-2-[(4-piperidino)styryllpyridinium bromide (0.85g), melting point 203-205'C.

Analysis Found: C30H45BrN2 requires C, 70.0%; H, 8.82%; N, 5.79%.

C, 70.2%; H, 8.83%; N, 5.45%.

Example 10

1-Hexyl-2[(4-piperidino)styryllpyridinium salt 2-Picoline (2.79g, 0.03 mole) and 1-bromo-hexane (5.0g, 0.03 mole) were heated in an oil bath at 130oC for five hours. The resulting oil was cooled and dissolved in methanol (40mi). 4-Piperidinobenzaidehyde (5.67g, 0.03 mole) and piperidine (0.25mi) were added and the mixture was refluxed under nitrogen fortwo hours.

The addition of about 100m] of etherto the cold solution gave red crystals which were collected and washed 25 to give 1-hexy]-2-[(4-piperidino)styryll-pyridinium bromide (2.1g), melting point 212-214'C (decomposition).

Analysis Found:

C241-133BrN2.1/41-120 requires C, 66.6%; H, 7.77%; N, 6.42%.

C, 66.4%; H, 7.80%; N, 6.50%.

Example 11 35 4-[4-(DimethylaminO)Styryll- 1-hexylpyridinium salt 4-Picoline (2.79g, 0.03 mole) and 1 -bromohexane (4.25mi, 0.03 mole) were heated in an oil bath at 130oC for 2 hours. The resulting brown oil was cooled. Methanol (40mi), 4-dimethylaminobenzaidehyde (4.5g, 0.03 mole) and piperidine (0.25mi) were added. The mixture was refluxed for 3 hours and cooled. A large volume of ether was added to form a crystalline product which was recrystallised by dissolving in isopropyl alcohol and adding either to give crystals of 4-[4-(dimethylamino)styryll-1 - hexylpyridinium bromide quarter hydrate (2.2g), melting point 224-226'C (decomposition). The compound exhibited infra-red spectral bands at 720, 815,835,883,940 987,1158,1330,1362,1522,1575 and 1640 wavenumbers.

Analysis Found: C2,H29BrN2.1/4H20 requires C, 64.0%; H, 7.58%; N, 7.20%.

C, 64.0%; H, 7.55%; N, 7.11 %.

Example 12 4-[4-(diethylamino)styrylj 1-hexylpyridinium salt By using a similar procedure to Example 11 with 4- diethylaminobenzaidehyde instead of 4dimethylaminobenzaidehyde,4-[4(diethylamino)styryll-1-hexylpyridinium bromide hernihydrate, meltingpoint 203-WC was prepared. The compound exhibited infra-red spectral bands at 703,729,813,829,891, 55 1001,1047,1076,1153,1175,1192,1269,1354, 1401,1517,1577 and 1641 wavenumbers.

Example 13 1-Hexyl-4-[4-(piperidino)styryllpyridinium saft By using a similar procedure to Example 11 with ethanol instead of methanol and 460 piperidinobenzaldehyde instead of 4- dimethylaminobenzaldehyde, 1-hexyl-4-[4(piperidino)styryllpyridinium bromide quarter hydrate was prepared. The compound exhibited infra-red spectral bands at 722, 846,889, 946,992,1168,1227,1335,1526,1592 and 1642 wavenumbers.

GB 2 148 280 A Example 14 4-[4-(dimethylamino)styryll-l-dodecylpyridinium salt By using a similar procedure to Example 11 with 1-bromododecane instead of 1- bromohexane, 4-[4-(dimethylamino)styryll-l-dodecylpyridinium bromide is prepared.

Example 15 1-Decyl-4[4-(Dimethylamino)styryllpyridinium saft The title compound bromide saltwas prepared by using a similar procedure to Example 11 with 1-bromodecane instead of 1-bromohexane and ethanol instead of methanol. The compound obtained 10 exhibited infra-red spectral bands at722, 846,889,946,992,1168,1227,1335,1526,1592 and 1642 wavenumbers.

Example 16 1-Hexyl-4-[4-(pyrrolidin- l-yl)styryllpyridinium salt The title compound bromide salt hernihydrate was prepared in a similar mannerto Example 13 using 15 4-(pyrrolidin-l-yi)benzaidehyde instead of 4-piperidinobenzaidehyde. The compound obtained exhibited infra-red spectral bands at 726,814,832,962, 999,1045,1173,1189,1211,1332,1524,1589 and 1642 wavenumbers.

Example 17 1-Decyl-4-[4-pryrrolidin-l-yl)styryllpyridinium salt The title compound bromide salt was prepared in a similar mannerto Example 16 using 1-bromodecane instead of 1-bromohexane and exhibited infra-red spectral bands at 723,847,888,1000,1177,1210,1333, 1526,1592 and 1642 wavenumbers.

Example 18- topical formulations (A) Oil in water emulsion base % w/w Compound of Example 11 (active compound) 1-2 30 White soft paraffin 15.0 Liquid paraffin 6.0 Cetostearyl alcohol 7.2 Cetomacragoi 1000 1.8 Benzyl alcohol 1.5 35 Propyl hydroxybenzoate 0.08 Methyl hydroxybenzoate 0.15 Water to 100.00 40 Meittogetherthe white soft paraffin, cetostearyl alcohol, cetomacragol 1000 and the liquid paraffin. Heat the water to about 60'C, dissolve the methyl and propyl hydroxybenzoate and the benzyl alcohol and add the resulting solution to the melted oil phase. Mix vigorously until cold.

The active compound may be incorporated into the aqueous phase or into the formed emulsion.

(B) Water in oil emulsion base Compound of Example 11 (active compound) Wool alcohols Hard paraffin White soft paraffin Liquid paraffin Water % w/w 1-2 3.0 12.0 5.0 30.0 100.0 Melt together the wool alcohols andthe paraffins. Heatthe waterto about60'C and addto the melted oil phase. Mix vigorously until cold.

The active compound may be incorporated into the water or into the formed emulsion.

11 GB 2 148 280 A 11 (C) Water soluble (miscible) base Compound of Example 11 (active compound) Polyethylene glycol 4000 Polyethylene glycol 400 Stearyl alcohol Water % W/W 1-2 31.5 54.0 4.5 100.0 Heat the glycols, stearyl alcohol and waterto about 6WC and mix together until cold. Incorporate the active 10 compound.

Example 19

Oral tablet mgItablet 15 Compound of Example 11 (active compound) 200.0 Avicel PH 101 200.0 Lactose BP 87.5 Water q.s. 20 AeDisol (a cellulose based disintegrant) 10.0 Magnesium Stearate BP 2.5 - 500.Omg Process Mix the active compound, Avicel PH 101 and lactose in a suitable mixer. Granulate with water, grade into a suitable size and dry in a suitable drier. Mix the dried granule with AcDisol and magnesium stearate. Compress on a suitable machine using round N/C tooling.

Example 20

Vaginal tablet mgItablet Compound of Example 11 (active compound) 100.0 35 Anhydrous lactose USP or Emcompress 4332.5 Maize starch BP 45.0 Magnesium stearate BP 22.2 4500.Omg 40 Emcompress is directly compressible dicalcium phosphate Process Mix the active compound, anhydrous lactose USP (or Emcompress), maize starch BP and magnesium stearate BP in a suitable mixer. Compress on a suitable machine fitted with almond shaped toolings.

A further aspect of the invention resides in the use of compounds containing a cation having formula la or lb and an anion as anti-fungal agents in agriculture or horticulture. Accordingly the invention further provides a method of combating fungal disease in a plant, comprising applying to the plant or seed of the 50 plant or to the locus of the plant or seed (for instance, land in which the plant is growing or to be grown) a compound containing a cation having formula la or lb. The invention further provides an anti-fungal composition comprising a compound containing a cation having formula la or lb as active ingredient and a carrier for the active ingredient. The compositions may be in the form of mixtures with fertilisers or liquid preparations for use as dips or sprays. The most appropriate amount of the active ingredient to be used for 55 horticultural or agricultural applications may be determined experimentally in known manner.

12 GB 2 148 280 A 12

Claims

1. For use as a pharmaceutical a compound containing a cation having the formula]a or 1b N CR CR NR6R 1 (E) 3r 4- 7 (1a) RI or C 2 'S R CRrCR4-(:YNR6R7 (1b) [in which R, represents alkyl containing at least 3 carbon atoms or aralkyl; R2 and R5 are independently hydrogen, lower alkyl, lower alkoxy, halogen or nitro; R3 and R4 are independently hydrogen or lower alkyl; and R6 and R7 are independently lower alkyl or aryl flower)alkyl or R6 and R7, when joined together, represent 20 a group having the formula 11 -(CH2)2-A-(CH2)2- (11) (where A is -(CH2)n-, 0, S or NRs where n is 0, 1 or 2 and R8 is lower alkyl) or a mono- or di- (lower alkyl) substitution product thereof] and a pharmaceutically acceptable anion.

2. A compound as claimed in Claim 1, for use as an anti-fungal agent.

3. A compound as claimed in Claim 1 or 2, wherein R5 and R6 are independently lower alkyl or aryl(lower)alkyl or R6 and R7, when joined together represent a group having formula 11.

4. A compound as claimed in Claim 1 or 2, wherein the said cation has formula lb.

5. A compound as claimed in Claim 3, wherein the said cation has formula lb.

6. Acompound as claimed in Claim 3 or5,wherein R, is alkyl of 3to 20 carbon atoms.

7. A compound as claimed in anyone of Claims 3,5 and 6, wherein R6 and R7 are independently methyl or ethyl or -NR6R7 is piperidino.

8. A compound as claimed in anyone of Claims 3 and 5 to 7, wherein R3 and R4 are, independently, hydrogen or methyl.

9. A compound as claimed in anyone of Claims 3 and 5to 8 wherein R2 and R5 are, independently, hydrogen or lower alkyl.

10. A compound as claimed in Claim 3, wherein the said cation is 2-[4(dimethylamino)styryll-lhexylpyridinium.

11. A compound as claimed in Claim 3, wherein the said cation is 2-[4(diethylamino)styryll-lhexylpyridinium.

12. A compound as claimed in Claim 3, wherein the said cation is 2-[4(dimethylamino)styryll-l- dodecylpyridinium.

13. A compound as claimed in Claim 3, wherein the said cation is 2-[4(diethylamino)styryll-ldodecylpyridinium.

14. A compound as claimed in Claim 3, wherein the said cation is4-[4(dimethylamino)styryll-lhexylpyridinium.

15. A compound as claimed in Claim 1 or 2, wherein the said cation is 4[4-dimethylamino)styryll-l- 50 dodecylpyridinium.

16. A compound as claimed in Claim 1 or2, wherein the said cation is 4-[4(diethylamino)styryll-l hexylpyridinium.

17. A compound as claimed in Claim 1 or2, wherein the said cation is 1decy]-4-[4 (dimethylamino)styryllpyridinium.

18. A compound as claimed in Claim 3, wherein the said cation is 1-benzyi2-[4 (dimethylamino)styryllpyridinium.

19. A compound as claimed in Claim 3, wherein the said cation is 1-benzyi2-[4 (diethylamino)styryllpyridinium.

13 GB 2 148 280 A 13

20. A compound containing a cation having the formula la or lb R:::-n z \ 5 d 1) CR=CR NR6 4 R7 R., or 2 ?5 4 R -NO / -CR2rCR J b) 4-NR6R7 (1' 1 -1\ A [in which R, represents alkyl containing at least 3 carbon atoms or aralkyl; R2 and R5 are independently hydrogen, lower alkyl, lower alkoxy, halogen or nitro; R3 and R4 are independently hydrogen or lower alkyl; and R6 and R7, when separate, are independently lower alkyl or aryl(lower)alkyl subject to the proviso that, if R6 and R7 are both lower alkyl, then R2. R4 and R5 are not all hydrogen or R6 and R7. when joined together, are 20 a group having the formula -(CH2)2-A-(CH2)2- (11) (where A is -(CH2)n-, 0, S or NR8 where n is 0, 1 or 2 and Ra is lower alkyl) or a mono- or di- (lower alkyl) 25 substitution product thereof) and a pharmaceutically acceptable anion.

21. A compound as claimed in Claim 20, wherein R6 and R7 areas defined in Claim 3.

22. A compound as claimed in Claim 21, wherein R2 is lower alkyl.

23. A compound as claimed in Claim 1, wherein R6 and R7 have formula 11.

24. A compound as claimed in Claim 21, wherein the said cation is 2-[4(diethylamino)styryll-5-ethyl-l- 30 propylpyridinium.

25. A compound as claimed in Claim 21, wherein the said cation is 2-[4(dimethylamino)styryll-5-ethyl-l- propylpyridinium.

26. A compound as claimed in Claim 21, wherein the said cation is 1dodecyl-2-[(4 piperidino)styryllpyridinium.

27. A compound as claimed in Claim 21, wherein the said cation is 1-hexyl2-[(4 piperidino)styryllpyridinium.

28. A compound as claimed in Claim 20, wherein the said cation is 1-hexyl4-[(4-piperidino)styrylI pyridinium.

29. A pharmaceutical composition comprising a compound as claimed in anyone of Claims 1, 2,4,15, 40 16,17, 20 and 28 in association or combination with a pharmaceutically acceptable carrier.

30. A pharmaceutical composition comprising a compound as claimed in anyone of Claims 3, 5to 14,18, 19 and 21 to 27 in association or combination with a pharmaceutically acceptable carrier.

31. A pharmaceutical composition as claimed in Claim 29 in unit dosage form.

32. A pharmaceutical composition as claimed in Claim 30 in unit dosage form.

33. A pharmaceutical composition as claimed in Claim 29 or 31 in the form of a tablet, capsule, sterile liquid composition, aerosol or a "semi-solid composition" (as defined herein).

34. A pharmaceutical composition as claimed in Claim 30 or 32 in the form of a tablet, capsule, sterile liquid composition, aerosol or a "semi-solid composition" (as defined herein).

35. A pharmaceutical composition as claimed in Claim 29 or 31 adapted fortopical administration. 50

36. A pharmaceutical composition as claimed in Claim 30 or 32 adapted for topical administration.

37. A compound as claimed in Claim 20, wherein the cation having formula [a or Ibis 1-(decyl or hexyl)-4-(4-(pyrro(idin-1-yl)styryllpyridinium.

38. A method of combating fungal disease in a plant, comprising applying a compound containing a cation having formula la or lb as defined and illustrated in Claim 1 to the plant or seed of the plant orto the 55 locus of the plant or seed.

39. An anti-fungal composition for horticultural or agricultural use containing a compound containing a cation having formula la or lb as defined and illustrated in Claim 1.

Printed in the UK for HMSO, D8818935, 4185, 7102.

Published by The Patent Office, 25 Southampton Buildings, London, WC2A lAY, from which copies may be obtained.