GB2124210A - Indoles - Google Patents

Description

(112)UK Patent Application (ig)GB (11) 2 124 210 A (21) Application No

8315564 (54) Indoles (22) Date of filing 7 Jun 1983 Priority data 8216526 7 Jun 1982 United Kingdom (GB) Application published Fab 1984 (51) INT CLI C07D 209/14 A61 K 31/40 (52) Domestic classification C2C 1343 1344 200 213 220 221 225 226 227 22Y 246 247 250 251 25Y 28X 29X 29Y 305 30Y 313 31Y 321 322323 326 327 328 32Y 332 339340342 34Y 351 352 364 36Y 385 388 43X 510 512 51X 532 533 534536 537 538 620 634 635 650 652 660 680 699 761 763 802 80Y AA SJ TP UlS 2415 C2C (56) Documents cited None

(58) Field of search

C2C (71) Applicant Glaxo Group Limited (United Kingdom) Clarges House 6-12 Clarges Street London WlY 813H (72) Inventors Michael Dennis Dowle fan Harold Coates (74) Agent and/or Address for Service Elkington and Fife High Holborn House 52/54 High Holborn London WCIV 6SH (30 (31 (32) (33 (43) (57) Indole derivatives of the general formula R1R2NSO2CHR3 (I) .07Nf H (where R, is H or an alkyl or alkenyl group; R2 is H, or an alkyl, alkenyl, aryl, aralkyl or cycloalkyl group; R3 is H or an alkyl group; R, and R,, are independently H or an alkyl or propenyl group or together form an aralkylidene group; and Alk is an optionally substituted alkylene chain) and their physiologically acceptable salts and solvates are potentially useful for the treatment of migraine.

ERRATUM SPECIFICATION NO 2124210A

AWNROS Page 21, line 60, after methanesulphonamide; insert 3-(2-aminoethyl)-N-(2- propenyl)-IH-indole-5methanesulphonamide; THE PATENT OFFICE 16 July 1984 Reprinted front p&" c c h h 4 h C 1 GB 2 124 21 OA 1 SPECIFICATION

Hoterocyclic compounds This invention relates to heterocyclic compounds, to processes for their preparation, to pharmaceutical compositions containing them and to their medical use. The present invention provides an indole of the general formula (1):

R1R2NSO2CHR3 AWNROS 10 H 15 wherein R, represents a hydrogen atom or a C1-6 alkyl or C3-6 alkenyl group; R2 represents a hydrogen atom or a C,3 alky], C3,, alkenyl, aryi, ar(C1- Aalkyl or C5-, cycloalkyl group; R3 represents a hydrogen atom or a C1-3 alkyl group; R, and R, which may be the same or different, each represents a hydrogen atom or a C1-3 alkyl or propenyl group or R. and R5 together form an aralkylidene group; and Alk represents an alkylene chain containing two or three carbon atoms which may be unsubstituted or substituted by not more then two C,_3 alkyl groups, and physiologically acceptable salts and solvates (e.g. hydrates) thereof.

All optical isomers of compounds of general formula (1) and their mixtures including the racemic mixtures thereof, are embraced by the invention.

Referring to the general formula (1), the alkyl groups in the general formula (1) may be straight chain or branched chain alkyl groups containing 1 to 3 carbon atoms, or in the case of R, 1 to 6, preferably 1 to 3, carbon atoms. Examples of an alkyl group include methyl, ethyl, propyl 30 and isopropyl groups. The alkenyl groups preferably contain 3 or 4 carbon atoms, examples of which include propenyl and butenyl groups. The cycloalkyl groups preferably contain 5 or 6 carbon atoms and examples include cyclopentyl and cyclohexyl groups. The term aryl, used as such or in the term aralkyl, preferably means phenyl. The alkyl moieties of the aralkyl groups preferably contain 1 or 2 carbon atoms. Examples of an aralkyl group include benzyi and 35 phenethyl groups. The aralkylidene group is preferably and aryl methylidene group such as benzylidene.

Suitable physiologically acceptable salts of the indoles of general formula (1) include acid addition salts formed with organic or inorganic acids for example hydrochlorides, hydrobrom ides, sulphates, fumarates, maleates and succinates. Other salts may be useful in the preparation of the compounds of general formula (1) e.g. creatinine sulphate adducts.

It is generally believed that the pain of migraine is of vascular origin and caused by excessive dilation of branches of the common carotid arterial bed (J.W. Lance, Mechanisms and Management of Migraine, Butterworths, p 113-152 (1973)) and a variety of vasoconstrictor agents have been shown to alleviate the headache. The comppounds of the invention mimic methysergide in contracting the dog isolated saphenous vein strip (E. Apperley et al., Br. J.

Pharmacol., 1980, 68, 215-224). Methysergide and ergotamine are known to be useful in the treatment of migraine and produce an increase in carotid vascular resistance in the anaesthetised dog; it has been suggested (P.R. Saxena., Eur. J. Pharmacol, 1974, 27, 99- 105 and P.R.

Saxena and G.M. De V1aam-Schiuter, Headache, 142, 1974) that this is the basis of their efficacy. Those compounds which we have tested selectively constrict the carotid arterial bed of the anaesthetised dog and the compounds according to the invention are thus potentially useful for the treatment of migraine.

Accordingly the invention also provides a pharmaceutical composition adapted for use in medicine which comprises at least one compound of formula (1), a physiologically acceptable salt 55 or solvate (e.g. hydrate) thereof and formulated for administration by any convenient route.

Such compositions may be formulated in conventional manner using one or more pharmaceuti cally acceptable carriers or excipients.

Thus the compounds according to the invention may be formulated for oral, buccal, parenteral or rectal administration or in a form suitable for administration by inhalation or insufflation. 60 For oral administration, the pharmaceutical compositions may take the form of, for example, tablets or capsules perpared by conventional means with pharmaceutically acceptable excipients such as binding agents (e.g. pregelatinised maize starch, polyvinylpyrrolidone or hydroxypropyl methylcel 1 u lose); fillers (e.g. lactose, microcrystalline cellulose or calcium phosphate); lubricants (e.g. magnesium stearate, talc or silica); disintegrants (e.g. potato starch or sodium starch 65 2 GB 2 124 21 OA 2 glycollate); or wetting agents (e.g. sodium lauryl sulphate). The tablets may be coated by methods well known in the art. Liquid preparations for oral administration may take the form of, for example, solutions, syrups or suspensions, or they may be presented as a dry product for constitution with water or other suitable vehicle before use. Such liquid preparations may be prepared by conventional means with pharmaceutically acceptable additives such as suspending 5 agents (e.g. sorbitol syrup, methyl cellulose or hydrogenated edible fats); emulsifying agents (e.g. lecithin or acacia); non-aqueous vehicles (e.g. almond oil, oily esters or ethyl alcohol); and preservatives (e.g. methyl or propyl p-hydroxybenzoates or sorbic acid).

For buccal administration the composition may take the form of tablets or lozenges formulated in conventional manner. 10 The compounds of the invention may be formulated for parenteral administration by injection, including using conventional catheterisation techniques or infusion. Formulations for injection may be presented in unit dosage form e.g. in ampoules or in multi-dose containers, with an added preservative. The compositions may take such forms as suspensions, solutions or emulsions in oily or aqueous vehicles, and may contain formulatory agents such as suspending, 15 stabilising and/or dispersing agents. Alternatively, the active ingredient may be in powder form for reconstitution with a suitable vehicle, e.g. sterile pyrogen-free water, before use.

The compounds of the invention may also be formulated in rectal compositions such as suppositories or retention enemas, e.g. containing conventional suppository bases such as cocoa butter or other glycerides. 20 For administration by inhalation the compounds according to the invention are conveniently delivered in the form of an aerosol spray presentation from pressurised packs or a nebuliser, with the use of a suitable propellant, e.g. dichlorodifluoromethane, trichlorofluoromethane, dichlorotetrafluoroethane, carbon dioxide or other suitable gas. In the case of a pressurised aerosol the dosage unit may be determined by providing a valve to deliver a metered amount. 25 Capsules and cartridges of e.g. gelatin for use in an inhaler or insufflator may be formulated containing a powder mix of a compound of the invention and a suitable powder base such as lactose or starch.

A proposed dose of the compounds of the invention for oral, parenteral, rectal or buccal administration to man for the treatment of migraine is 0. 1 to 100 mg of the active ingredient 30 per dose which could be administered, for example 1 to 4 times per day.

Aerosol formulations are preferably arranged so that each metered dose or--puff---of aerosol contains 20 Itg- 1000 gg of a compound of the invention. The overall daily dose with an aerosol will be within the range 100 jug- 10 mg. Administration may be several times daily, for exa ple 2, 3, 4 or 8 times, giving for example 1, 2 or 3 doses each time. The overall daily dose and the 35 metered dose delivered by capsules and cartridges in an inhaler or insufflator could be double those with aerosol formulations.

A preferred class of compounds represented by the general formula (1) is that in which R, represents a hydrogen atom or a C1-6 alkyl group and R2 represents a hydrogen atom or a C1-3 alky], C3-6 alkenyl or ar(C,Aalkyl group.

Another preferred class of compounds represented by the general formula (1) is that in which R3, represents a hydrogen atom.

A further preferred class of compounds is that wherein, in the general formula (1), R. and R5, which may be the same or different, each represents a hydrogen atom or a C1-3 alkyi group, for example, a methyl group.

A preferred class of compounds failing within the scope of general formula (1) is that wherein R, represents a hydrogen atom or a C1-3 alkyl group e.g. a methyl group; R2 represents a hydrogen atom or a Cl-, alkyl group, e.g. a methyl, ethyl or isopropyl group, a C3-4 alkenyl group e.g. a propenyl group or an ar(C1-2)aikyl group e.g. a benzyl group; R3 represents a hydrogen atom; and R4 and IR,, which may be the same or different, each represents a hydrogen 50 atom or a Cl-3alkyl group e.g. a methyl group; and physiologically acceptable salts and solvates (e.g. hydrates) thereof.

A particularly preferred class of compounds according to the invention is that wherein R, represents a hydrogen atom or a C1-3 alkyl group e.g. a methyl group; R2 represents a C1-3 alkyl group e.g. a methyl group, or a C3-4 alkenyl group e.g. a propenyl group; R3 and R4 each represents a hydrogen atom; and R. represents a hydrogen atom or a C1-3 alkyl group e.g. a methyl group; and physiologically acceptable salts and solvates (e.g. hydrates) thereof.

Preferred compounds according to the invention include:3-(2-(methylamino)ethyi)-N-methyi-1 H-indole-5-methanesulphonamide; 3-(2-arn inoethyi)-N, N-d i methyl- 1 ki-indole-5-methanesulphonamide; 3-(2-aminoethyi)-N-(2-propenyi)-1 H-indole-5-methanesulphonamide; and physiologically acceptable salts and solvates (e.g. hydrates) of these compounds. A particularly preferred compound according to the invention is:- 3-(2-aminoethyl)-N-methyl-l H-indole-5-methanesulphonamide and the physiologically accept able salts (e.g. the hydrochloride and succinate salts) and solvates (e.g. hydrates) thereof. 65 3 GB 2 124 21 OA 3 According to another aspect of the invention, compounds of general formula (1) and their physiologically acceptable salts and solvates (e.g. hydrates) may be prepared by the general methods outlined hereinafter. In the following processes, IR,, R2, R3, R4, R,, and Alk are as defined for the general formula (1) unless otherwise specified.

According to a general process (A), compounds of general formula (1) may be prepared by 5 cyclisation of compounds of general formula (ii):

R1R2NSO2CHR3.".

10 NI-IN=CHCH2AikQ (wherein Q is the group NR4R. or a protected derivative thereof or a leaving group such as a 15 halogen atom (e.g. chloride or bromine), or an acyloxy group such as acetoxy, chloroacetoxy, dichloroacetoxy, trifluoroacetoxy or p- nitrobenzoyloxy or a sulphonate group such as p-toluene sulphonate or methyl sulphonate).

Particularly convenient embodiments of the process are described below.

When Q is the group NR,R. (or a protected derivative thereof), the process is desirably carried 20 out in a suitable reaction medium, such as an aqueous organic solvent, for example, an aqueous alcohol (e.g. methanol, ethanol and isopropanol) or aqueous ether (e.g. dioxan) in the presence of an acid catalyst. (In some cases the acid catalyst may also act as the reaction solvent). Suitable acid catalysts include inorganic acids such as sulphuric or hydrochloric acid or organic carboxylic acids such as acetic acid. Alternatively the cyclisation may be carried out using polyphosphate ester in a chlorinated solvent (e.g. chloroform) or using a Lewis acid such as zinc chloride in ethanol or boron trifluoride in acetic acid. The reaction may conveniently be carried out at temperatures of from 20 to 200C, preferably 50 to 125C.

When Q is a leaving group, such as a chlorine or bromine atom, the reaction may be effected in an aqueous organic solvent, such as an aqueous alcohol (e.g. methanol, ethanol or isopropanol) or an aqueous ether (e.g. dioxan), in the absence of an inorganic acid, conveniently at a temperature of from 20 to 200C, preferably 50 to 1 25C. This process results in the formation of a compound of formula (1) wherein R4 and R. are both hydrogen atoms.

According to a particular embodiment of this process, compounds of general formula (1) may be prepared directly by the reaction of a compound of general formula (111):

R1 R2NSO2CHR3 (11) NHNH2 or a salt (e.g. the hydrochloride salt) thereof, with a compound of formula (IV):

HCOCH2AIkQ (IV) (wherein G is as defined above) or a salt or protected derivative thereof (such as an acetal, for example, a dialkyl or cyclic acetal e.g. formed with an appropriate alkyl orthoformate or diol or protected as a bisulphite addition 50 complex), using the appropriate conditions as described above for the cyclisation of a compound of general formula (11) (The Fischer-Indole Synthesis, B. Robinson p 488- Wiley 1982).

Compounds of general formula (11) may, if desired, be isolated as intermediates by reacting a compound of formula (111), or a salt or protected derivative thereof with a compound of formula (]V) or a salt or protected derivative thereof, in a suitable solvent, such as an aqueous alcohol 55 (e.g. methanol) or an aqueous ether (e.g. dioxan) and at a temperature of, for example, from 20 to 3WC. If an acetal of a compound of formula (IV) is used it may be necessary to carry out the reaction in the presence of an acid (for example, acetic or hydrochloric acid).

As illustrated in the following general processes (B) and (C), the aminoalkyl substituent -AlkNRA, may be introduced at the 3-position by a variety of conventional techniques which 60 may, for example, involve modification of a substituent at the 3-position or direct introduction of the aminoalkyl substituent into the 3-position.

Thus a further general process (B) for preparing compounds of general formula (1) involves reacting a compound of general formula (V):

4 GB 2 124 21 OA 4 R1 R2NSO2CHR3 (M) lkY 4!p, ",n 1 Z1. 1 H (wherein Y is a readily displaceable group) or a protected derivative thereof, with a compound of formula R4R.NI-1.

This displacement reaction may conveniently be carried out on those compounds of formula (V) wherein the substituent group Y is a halogen atom (e.g. chlorine, bromine or iodine) or a group OR where OR is, for example, an acyloxy group, such as acetoxy, chloroacetoxy, dichloroacetoxy trifluoroacetoxy, or p-nitrobenzoloxy or a sulphonate group (e.g. p-toluene sulphonate or methyl sulphonate).

The above reaction is conveniently effected in an inert organic solvent (optionally in the presence of water), examples of which include alcohols, e.g. ethanol; ethers, e.g. tetrahydrofu ran; esters e.g. ethyl acetate; amides e.g. N,N-dimethyiformamide; and ketones e.g. acetone.

The process may be carried out at a temperature of, for example, - 10 to + 1 WC, preferably 20 to WC. 20 The compounds of formula (V) wherein Y is a halogen atom may be prepared by reacting a hydrazine of formula (111) with an aldehyde (or a protected derivative thereof) of formula (IV) in which G is a halogen atom, in an aqueous alcohol (e.g. methanol) or an aqueous ether (e.g.

dioxan) containing an acid (e.g. acetic or hydrochloric acid) or by reacting a compound of general formula (V) wherein Y is a hydroxy group with the appropriate phosphorus trihalide. The 25 intermediate alcohol, wherein Y is a hydroxy group, may also be used to prepare compounds of formula (V), wherein Y is a group OR, by acylation or sulphonylation with the appropriate activated species (e.g. anhydride or sulphonyl chloride) using conventional techniques.

Compounds of general formula (1) may also be prepared by another general process (C) involving reduction of a compound of general formula (Vi):

R1 R2N SO 2CHR3,,,, (M) H W (wherein W is a group capable of being reduced to give the required AWNR4R5 group or a 40 protected derivative thereof) or a salt or protected derivative thereof.

The required Alk and NR4R. groups may be formed by reduction steps which take place separately or together in any appropriate manner.

Examples of groups represented by the substituent group W include the following:- TN02 (where T is Alk or an alkenyl group corresponding to the group (Alk); AWN3; AWNR4COR51; -COCONR4R5; (CHRJ.CHR7M; CHR7COZ; (CHR.J.CR7= NOH; CH(O1-1)CHR,NR4R5; COCHR7Z (wherein R,, and R7 which may be the same or different, each represents a hydrogen atom or aCl-3alkyl group, Z is an azido group N3or the group NR4R5or a protected derivative thereof, x is zero or 1 and R.' is part of the group R5 or the group ORc where Rc is an alkyl or an aralkyl group).

Groups which may be reduced to the group Alk include corresponding unsaturated groups and corresponding groups containing one or more hydroxyl groups or carbonyl functions.

Groups which may be reduced to the group NR^ wherein R4 and R,, are both hydrogen include nitro, azido, hydroxyimino and nitrile groups. Reduction of a nitrile group yields the group CH2NH2 and thus provides a methylene group of the group Alk.

The required N114R., group wherein R4 and/or R,, are other than hydrogen may be prepared by reduction of a nitrile (CHRJ.CHR7CN or an aldehyde (CHRJ.CHRCl-10 (wherein R,, R, and x are as previously defined) in the presence of an amine, R4R,.M.

A particularly suitable method for preparing a compound of formula (1) wherein R, and/or Rr, is other than hydrogen, is reductive alkylation of the corresponding compound wherein R4 and/or R. represents hydrogen, with an appropriate aldehyde or a ketone (e.g. acetaldehyde or benzaidehyde or acetone) in the presence of a suitable reducing agent. In some instances (e.g. for the introduction of the group R,, where R. is ethyl) the aldehyde (e.g. acetaidehyde) may be condensed with the primary amine and the intermediate thus formed may subsequently be reduced using a suitable reducing agent.

GB 2 124 21 OA 5 A compound of general formula (1) where R. is a hydrogen atom, may also be prepared by reduction of a corresponding compound of general formula (1) wherein R. is a benzyi group, for example with hydrogen in the presence of a catalyst e.g. 10% palladium on carbon.

The required N%Rr, group wherein R4 and/or R. are other than hydrogen may also be prepared by reduction of a corresponding amide, for example, ARNR,COR1 (where R' is as 5 previously defined).

It will be appreciated that the choice of reducing agent and reaction conditions will be dependent on the nature of the group W.

Suitable reducing agnts which may be used in the above process for the reduction of compounds of formula (V1) wherein W represents, for example, the groups TN02, AWN3, 10 (CHR,).CHR,CN, (CHR6).Cr, = NOH, CH(OH)CHR,NRR, (where T, R51, R,, and R, and x are as previously defined) include hydrogen in the presence of a metal catalyst, for example Raney Nickel or a noble metal catalyst such as platinum, platinum oxide, palladium or rhodium, which may be supported, for example, on charcoal, kieselguhr or alumina. In the case of Raney Nickel hydrazine may also be used as the source of hydrogen. This process may conveniently be carried out in a solvent such as an alcohol e.g. ethanol, an ether, e.g. dioxan or tetrahydrofuran, an amide, e.g. dimethylformamide or an ester e.g. ethyl acetate, and at a temperature of from - 10 to + WC, preferably - 5 to + WC.

The reduction process may also be effected on compounds of formula (V1) wherein W represents, for example, the groups TN02, AWN31 CH(O1-1)CHR7M4R5 or COCHR7Z (where T, R7 20 and Z are as previously defined), using an alkali metal or alkaline earth metal borohydride or cyanoborohydride e.g. sodium or calcium borohydride or cyanoborohyd ride which process may conveniently be carried out in an alcohol such as propanol or ethanol and at a temperature of from 10 to 1 OWC, preferably 50 to 1 OWC. In some instances the reduction using a borohydride may be carried out in the presence of cobaltous chloride.

Reduction of compounds of formula (V1) wherein W represents, for example, the groups TN02, AWN3, AWNR,COR51, CHR7COZ, (CHRJ,,CR7 = NOH, CH(O1-1)CHR7NR,R5, - COCONR,R, and COCHR7Z (wherein T, %, R6, R71 Z and x are as previously defined) may also be carried out using a metal hydride such as lithium aluminium hydride. This process may be carried out in a solvent, for example, and ether such as tetrahydrofuran, and conveniently at a temperature of 30 from - 10 to + 1 OWC, preferably 50 to 100 C.

A particular embodiment of this process includes the reduction of a compound of formula (V1) wherein W is the group CHRCN, for example, by catalytic reduction with hydrogen in the presence of a catalyst such as palladium or rhodium on alumina, optionally in the presence of an amine I-INR,Rs, or using lithium aluminium hydride.

The starting materials or intermediate compounds of general formula (V1) may be prepared by analogous methods to those described in U.K. Published Patent Application No. 2035310 and ---AChemistry of Heterocyclic Compounds- 1 ndoles Part ll- Chapter VI edited by W.J. Houlihan (1972) Wiley Interscience, New York.

A compound of formula (V1) wherein W is the group AWNI-IC0Rj.' may be prepared by 40 acylation of the corresponding unsubstituted amine using conventional techniques.

The Fischer-indole cyclisation process may be employed to prepare a compound of formula (V1) wherein W is the group (CHR.),CHR7CN or CHR.CHR7NO2 in conventional manner.

The following reactions (D), in any appropriate sequence, may if necessary and/or desired be carried out subsequent to any of the above described processes: (i) conversion of one compound of general formula (1) or a salt or protected derivative thereof into another compound of general formula (1); (ii) removal of any protecting groups; and (iii) conversion of a compound of general formula (1) or a salt thereof into a physiologically acceptable salt or solvate (e.g. hydrate) thereof.

Thus, a compound of formula (1) according to the invention may be converted into another compound of the invention using conventional procedures.

For example, a compound of general formula (1) wherein one or more of R, IR, R, and R, are alkyl groups may be prepared from the corresponding compounds of formula (1) wherein one or more of R, R2, R4 and R. represent hydrogen atoms, by reaction with a suitable alkylating agent 55 such as an alkyl halide (e.g. methyl or ethyl iodide), alkyl tosylate (e.g. methyl tosylate) or dialkylsulphate (e.g. dimethyisulphate). The alkylation reaction is conveniently carried out in an inert organic solvent such as an amide (e.g. dimethylformamide), an ether (e.g. tetrahydrofuran) or an aromatic hydrocarbon (e.g. toluene) preferably in the presence of a base. Suitable bases include, for example, alkali metal hydrides, such as sodium hydride, alkali metal amides, such as 60 sodium amide, alkali metal carbonates, such as sodium carbonate or alkali metal alkoxides such as sodium or potassium methoxide, ethoxide or t-butoxide.

It should be appreciated that in some of the above transformations it may be necessary or desirable to protect any sensitive groups in the molecule of the compound in question to avoid undesirable side reactions. For example, during any of the reaction sequences described above, 65 so 6 GB2124210A 6 it may be necessary to protect the group NRRr,, wherein R4 and/or R., represents hydrogen, with a group easily removable at the end of the reaction sequence. Such groups may include, for example, aralkyl groups, such as benzyl, diphenylmethyl or triphenylmethyl; or acyl groups such as N-benzyloxycarbonyl or t-butoxycarbonyl or phthaloyl.

In some cases, it may also be desirable to protect the indole nitrogen with, for example, an 5 aralkyl group such as benzyl.

Subsequent cleavage of the protecting group may be achieved by conventional procedures.

Thus an aralkyl group such as benzyl, may be cleaved by hydrogenolysis in the presence of a catalyst (e.g. palladium on charcoal) or sodium and liquid ammonia; an acyl group such as N- benzyloxycarbonyl may be removed by hydrolysis with, for example, hydrogen bromide in acetic 10 acid or by reduction, for example by catalytic hydrogenation. The phthaloyl group may be removed by hydrazinolysis (e.g. by treatment with hydrazine hydrate) or by treatment with a primary amine (e.g. methylamine).

Where it is desired to isolate a compound of the invention as a physiologically acceptable salt, for example as an acid addition salt, this may be achieved by treating the free base of general 15 formula (1), with an appropriate acid (e.g. succinic or hydrochloric acid) preferably with an equivalent amount in a suitable solvent (e.g. aqueous ethanol).

The starting materials or intermediate compounds for the preparation of the compounds according to this invention may be prepared by conventional methods analogous to those described in U.K. Published Patent Application No. 2035310.

As well as being employed as the last main step in the preparative sequence, the general methods indicated above for the preparation of the compounds of the invention may also be used for the introduction of the desired groups at an intermediate stage in the preparation of the required compound. Thus, for example, the required group at the 5- position may be introduced either before or after cyclisation to form the indole nucleus. It should therefore be appreciated that in such multi-stage processes, the sequence of reactions should be chosen in order that the reaction conditions do not affect groups present in the molecule which are desired in the final product.

The invention is further illustrated by the following Examples. All temperatures are in C.

The invention is further illustrated by the following examples. All temperatures are in C. 'Hyflo' 30 is a filtration aid. Chromatography was carried out using silica gel (Merck, Kieselgel 60, Art. 7734) and t.l.c.thin layer chromatography, on silica (Macherly-Nagel, Polygram) except where otherwise stated. The following abbreviations define the eluent used for chromatography and t.l.c.

(A) Methylene chloride-ethanol-0.88 ammonia 100:8A (B) Methylene chloride-ethanol-0.88 ammonia 40:8A (C) Cyclohexane-ethyl acetate 1:4 (D) Ethyl acetate-toluene 1:1 (E) Ethyl acetate-toluene 3:7 (F) Methylene chloride-ethanol-0.88 ammonia 30:8A (G) Methylene chloride-ethanol-0.88 ammonia 150:8A (H) Methylene chloride-ethanol-0.88 ammonia 25:13:1 (1) Chloroform- methanol 97:3 (J) Methylene chloride-ethanol-0.88 ammonia 20:8A (K) Ethyl acetate- isopropanol-water-0. 8 8 ammonia 20:10:8A (L) Ethyl acetate-isopropanol-water-0.88 ammonia 25:15:8:2 (M) Methylene chloride- methanol 95:5 (N) Methylene chloride-ethanol-0.88 ammonia 50:8A(0) Methylene chloride-ethanol-0.88 ammonia 10:8A (P) Chloroform- methanol 95:5 (G) Methylene chloride-ethanol-0.88 ammonia 200:8A Intermediates were routinely checked for purity by fl.c. employing u.v. light for detection and spray reagents such as DNP and potassium permanganate. In addition indolic intermediates 55 were detected by spraying with aqueous ceric sulphate and tryptamines by spraying with a colution of iodoplatinic acid or ceric sulphate.

Example 1

3-(2-Aminoethyi)-N-methyi-1H-indole-5-methanesulphonamide, maleate (a) 4-Amino-N-methylbenzenemethanesulphonamide, hydrochloride A suspension of N-methyl-4-nitrobenzenemethanesulphonamide (30g) in ethanol (1 50mi), water (300ml) and hydrochloric acid (2N, 65ml) was hydrogenated over 10% palladium oxide on charcoal (7.5g, 50% paste with water) until hydrogen uptake ceased (9. 751). The catalyst was 65 7 (c) 3-(2-Aminoethyl)-N-methyl-1H-indole-5-methanesulphonamide, maleate A solution of 4-Hydrazino-N-methylbenzenemethanesulphonamide hydrochloride (109) and 4chlorobutanal dimethyl acetal (6.59) in ethanol/water (5A, 500mi) was heated at reflux for 2h. The solution was then cooled and evaporated to dryness under reduction pressure. The orange- brown residue was purified by column chromatography (B) to give the tryptamine as an oil (3.99). A solution of this material (3.9g) in ethanol (50mi) and methanol (1 Omi) was treated with a solution of maleic acid (1. 7g) in ethanol (1 Orni) and the resulting solution was concentrated to a thick oil which solidified on cooling to give the title compound, m.p. 140-1 Analysis Found: C, 50. 1; H, 5.3; N, 10. 6.

C121-117N302S.C41-1404 requires C,50.1;1-1,5.5;N,11.0%. T.I.c. (F) Rf 0. 26 GB2124210A 7 removed by filtration through---hyflo- and the filter pad was washed with water (30mi). The filtrate was evaporated under reduced pressure to give the title compound as a pale yellow powder (28.29) m.p. 143-144C.

(b) 4-Hydrazino-N-methylbenzenemethanesulphonamide, hydrochloride A solution of sodium nitrite (1 3.72g) in water (1 60mi) was added slowly to a cooled stirred mixture of 4-Amino-N-methylbenzene methanesulphonamide (39.3g), water (240mi) and conc. hydrochloric acid (400mi) such that the temperature did not exceed 00. After stirring for 1 5min this mixture was added slowly to a cold solution of stannous chloride dihydrate (22 1.1 g) in conc. hydrochloric acid (400mi) again keeping the temperature below 00. Once the addition was 10 complete the mixture was allowed to warm to room temperature (1h). The solid was collected by filtration, washed well with diethyl ether (4 X 250mi) and dried at 45' to give the title compound as a white powder (31. 6g). An assay by periodate titration showed this to be 91.3% pure. T.I.c. (A) Rf 0.4.

Example 2 3-(2-Aminoethyi)-N-methyi- 1 H -indole-5-methanesulphonamide, maleate (a) 3-[2-(1,3-Dihydro-1,3-dioxo-2H-isoindol-2-yi)ethyi]-N-methyl-1Hindole-5-met hanesulphonamide A suspension of the product of example 1 (b) (7g) and 2-(4,4-diethoxybutyl)-1 H -isoindole1,3(2H)-dione (8. 15g) in dilute acetic acid (25%, 450mi) was stirred at room temperature for 0.5h and then heated at reflux for l h. The resulting suspension was partitioned between water 35 (11) and ethyl acetate (200mi). The aqueous layer was extracted with more ethyl acetate (3 X 250mi). The organic extracts were combined, washed with saturated sodium bicarbonate (to pH7) and dried (MgSO4). Evaporation of the solvent gave the title compound as a yelloworange foam (4.5g) which was used in the next stage without further purification. T.I.c. (C) Rf 0.63 impurities at Rf 0.45 and 0.07.

(b) Phenyimethyl[2-[5-[[(methylamino)sulphonyl]methyl]-lH-indol-3yi]ethyljcarba mate A hot solution of the product of stage (a) (4.5g) in ethanol (70ml) was treated with hydrazine hydrate (2.8mi) and heated at reflux for 2h. Solvent was evaporated, the residual solid suspended in sodium carbonate (2N; 50ml) and tetrahydrofuran (20ml) and treated with benzyl 45 chloroformate (3.1 5ml). After 2h the aqueous layer was also extracted with ethyl acetate (4 X 50mi), the extract dried (MgS04) and solvent evaporated. Chromatography (D) gave the title compound as a yellow foam (2.5g) which was used in the next stage without further purification.

T.I.c. (E) Rf 0.35 (c) 3-(2-Aminoethyi)-N-methyl- 1 H -indole-5-methanesulphonamide, maleate A solution of the product of stage (b) (0.85g) in methanol (1 Orni) was hydrogenated over prereduced palladium oxide on carbon (10%, 300mg) at room temperature and atmospheric pressure for 6h (uptake of hydrogen 30mi). The catalyst was filtered off (hyflo)and washed with methanol (100mi). The filtrate was concentrated and the residual white solid (0.569) purified by column chromatography (F) to give the tryptarnine as a white foam (0.26g). Part of this (0. 1 3g) in absolute ethanol (5mi) was treated with maleic acid (0.0529) and the solvent was evaporated. The residual oil crystallised from tetrahydrofuran (5mi) with a few drops of ethanol to give the title compound as an off-white solid, m.p.. 150-40 (0.11 g).

Analysis Found Q50.2; H,5.6; W10.7; C121-117N.02S,C41-1404 requires: Q50.1; W5.5; W10.9% T.I.c. (F) Rf 0.26 8 GB 2 124 21 OA 8 Example 3

3-(2-Aminoethyl-N-methyl-1H-indole-5-methanesulphonamide (a) 4-[2-(3-Cyanopropylidene)hydrazino]-N- methyibenzenemethanesulphonamide A solution of the product of example 1 (b) (29) and 3-cyanopropanal dimethylacetal (1.4g) in water (25mi) was treated with dilute hydrochloric acid (2N; 5 drops) and stirred for 24h at room 5 temperature. The resulting white solid was filtered off, washed with water (20mi), ether (1 00mi) and dried in vacuo at 40' to give the title compound (2.1 g) m.p. 124-125.

(b) 3-(Cyanomethyi)-N-methyi-1H-indole-5-methanesulphonamide A suspension of the product from stage (a)(0.7g) in polyphosphate ester (7g) and chlorform 10 (1 4mi) was heated at ref lux for 5 min. and then poured onto ice. The resulting suspension was stirred with ice for 20 min., then extracted with chloroform (4 X 20mi) and the extract dried.

Solvent was then removed and the residue purified by column chromatography (G). The title compound was obtained as a reddish semi-solid (0.389) which was impure and was employed directly in the next stage.

T.I.c. (G) Rf 0.4 with impurities at Rf 0.44 and 0.46.

(c) 3-(2-Aminoethyl)-N-Methyl-1H-indole-5-methanesulphonamide A solution of the product of stage (b) (0. 1 5g) in methanolic ammonia was hydrogenated over pre-reduced rhodium on alumina (5%, 0.15g) for 18h at room temperature and atmospheric 20 pressure. T.I.c (F) showed the solution contained a major component Rf 0. 26 identical with that of 3-(2-aminoethyi)-N-methyi-l H-indole-5-methanesulphonamide prepared by the method of example 1.

Example 4

3-(2-Aminoethyl)-N-methyl-1H-indole-5-methanesulphonamide To a solution of the product of example 3(b) (0. 159) in dry tetrahydrofuran (20mi) was added lithium aluminium hydride (0. 1 5g) and the resulting suspension was heated at ref lux (under a nitrogen atmosphere) for 1 h. Excess lithium aluminium hydride was destroyed by addition of ethyl acetate (5mi), followed by addition of aqueous potassium carbonate (1 Omi; saturated). The 30 aqueous layer was extracted with ethanol (1 Orni). Solvent was evaporated under reduced pressure, and the residual oil purified by column chromatography (H) to give the title compound slightly impure as an oil (21 mg) which was shown by -n.m.r. and fl.c. (F) Rf 0.26 to be identical with a sample prepared by the method of example 1.

Example 5

3.(2-Aminoethyl)-N-methyl- 1 H -indole-5-methanesulphonamide (a) N-Methyl-4-[2-(4-Nitrobutylidene)hydrazinolibenzenemethane sulphonamide.

To a solution of the product of example 1 (b) (19) in water (20mi) was added 4-nitrobutanal (0.5g) and an oil separated within a few minutes. The resulting suspension was extracted with 40 dichloromethane (4 X, 20mi), the extracts dried (M9S04) and the solvent evaporated in vacuo to give the title compound as a thick oil (1.089) Analysis Found: CA5.3;H,5.6Xl 7.3.

C,,H,,N40,S.O.2H20 requires C,45.6;1-1,5.2;PJA 7.7% T.I.c. isopropyl acetate /cyclohexane (11) Rf 0.26 (b) N-Methyl-3-(2-nitroethyl)-lH-indole-5-methanesulphonamide A solution of the product of stage (a) (2g) in chloroform (40ml) and polyphosphate ester (20g) was heated under reflux for 3 min. and then poured onto ice (50g) and sodium bicarbonate (8%, 20ml). The mixture was stirred at room temperature for 30 minutes and extracted with chloroform (4 X 50mi). The organic extracts were dried (MgS04) and concentrated. The residue was purified by flash chromatography (Merck 9385) (1) to give the title compound as an oil (0.729) which was used in the next stage without further purification. T. I.c. (Q) Rf 0.26 N.m.r. 5.2, (triplet CH2 N02) ' (c) 3-(2-Aminoethyi)-N-methyl-1H-indole-5-methanesulphonamide A solution of the product of stage (b) (0. 1 3g) in ethyl acetate (5mi) was hydrogenated over pre reduced 10% palladium oxide on charcoal (0.29, 50% paste with water) for 2h, whereupon hydrogen uptake (20mi) ceased. The catalyst was removed by filtration (hyflo) and the filtrate concentrated. The residue was purified by flash chromatography (Kiselgel 9385) to give the title 60 compound (8mg) as an oil which was shown by t.l.c. (F) Rf 0.26 to be identical with the product of example 1.

Example 6

3-(2-Aminoethyl)-N-methyi-1H-indole-5-methanesulphonamide 9 GB 2 124 21 OA 9 (a) 4-[2-(4-Chlorobutylidene)hydrazinol-N-methyibenzenemothanesulphonamide A mixture of the product of example 1(b) (0.54), 4-chlorobutanal dimethyl acetal (0.30g), water (4mi) and hydrochloric acid (2N; 2 drops) was stirred at room temperature for 1.5h. The mixture was filtered, and the solid was washed with water (20mi), air-dried (1 h), and dried overnight in vacuo over phosphorus pentoxide to give the title compound as a cream solid (0.44g), m.p. 5 77-79 (dec.).

(b) 3-(2-Chlorethyl)-N-methyi-1H-indole-5-methanesulphonamide A solution of the product from stage (a) (0.29g) in chloroform (3mi) was added to a solution of polyphosphate ester (2.92g) in chloroform (2mi), and the yellow solution was heated at reflux 10 for 5min. The resulting brown solution was then immediately poured onto ice (ca 20g), carefully diluted with sodium bicarbonate solution (8%; ca 50mi) until basic, and stirred at room temperature for 15min. The mixture was then extracted with chloroform (3 X 20mi), and the combined organic extract was washed with brine (20mi), dried (M9SOJ and evaporated in vacuo to give the title compound crude as a yellow-brown oil (0.609) which was used in the 15 next step without further purification. T.I.c. (1) major components Rf 0. 25, 0.32, minor products Rf 0.0, 0.05, 0.43 and 0.57.

(c) 3-(2-Aminoethyi)-N-methyl-1H-indole-5-methanesulphonamide A solution of the product of stage (b) (0.609) in methanol (4mi) was diluted with ammonium 20 hydroxide (30mi), and the suspension was stirred in an autoclave at 90 for 11 Ornin. The mixture was filtered, and the filtrate was evaporated in vacuo to give a yellow gum, which was azeotroped with absolute ethanol (2 X 30mi) to give a sticky solid (0. 46g). This material was purified by chromatography (J) to give the title compound as a pale yellow oil (0.036g) shown by t.l.c. (J) Rf 0.23 and n.m.r. to be identical with that of the product of example 1.

Example 7

3-(2-Aminoethyl)-N-methyl-lH-indole-5-methanesulphonamide, hydrochloride To a solution of the tryptamine free base (0.267g) prepared by the method of example 1 in ethanol (3ml) was added 3.1 N ethanolic hydrogen chloride until the solution was just acidic. 30 The yellow solution was heated to boiling and on cooling the title compound separated as pale cream micro needles (0.26g), m.p. 229-231 C.

Analysis Found: CA7.7; H, 6. 1; N, 13.4.

C,H17N3025MC1 requires CA7A H, 6.0; N, 13.8% 35 T.I.c. (J) Rf 0.3 Example 8

3-(2-Aminoethyl)-N-methyi-lH-indole-5-methanesulphonamide, hemisuccinate To a hot solution of the tryptamine free base (0.267g) prepared by the method of example 1 in 40 ethanol (3ml) was added a hot solution of succinic acid (0.059g) in ethanol (3ml). On cooling the title compound separated as an off-white powder (0.29g), m.p. 179-181 C Analysis Found: C,51.5;H,6.22;N,12.6.

C12H17N.O2S.0.5C4H6O4 requires C,51.5;H,6.2;N, 12.9% T.I.c. (J) Rf 0.30 Example 9

3-(2-Aminoethyl)-N-(phenyimethyl)-1H-indole-5-methanesulphonamide, compound with creatin ine, sulphuric acid and water (1: 1: 1: 1.2) (a) 4-Nitro-N-(phen methyl)benzenemethanesulphonamide Benzylamine (0.8ml) was added in one portion to a solution of 4- nitrobenzenemethanesulphonyl chloride (0.6g) in dichloromethane (50ml) stirred at ambient temperature. A white solid precipitated at once. Stirring was continued for 1 h, solvent was evaporated and the residual solid washed with water (1 00mi), ether (200mi) and dried. The title compound was obtained as a white solid (0.64g) m.p. 180-1. A sample (0.2g) was recrystallised from hot ethanol (5ml) to 55 give analytically pure material as an off-white solid (0. 1 5g), m.p. 182- 3% (b) 4-Amino-N-(phenylmethyl)benzenemethanesulphonamide A suspension of the product of stage (a) (5g) in methanol (1 50ml) was hydrogenated over pre reduced 10% palladium oxide on charcoal (1 g) at room temperature and pressure. Hydrogen 60 uptake was complete in 20 min. after 1. 11 had been adsorbed. Catalyst was filtered off (hyflo), washed with more methanol (500ml) and the solvent evaporated. The product was obtained as an off-white solid (3.75g), m.p. 116-7. A small sample (0.1 5g) was crysallised from hot methanol (3ml) and few drops of ether to give the title compound (0.1g) m. p. 117-1118% GB2124210A 10 (c) 4-Hydrazino-N-(phenylmethyl)benzenemethanesulphonamide, hydrochloride A thick suspension of the product of stage (b) (3.68g) in conc. hydrochloric acid (50mi) was stirred at - 5' whilst a solution of sodium nitrate (0. 9g) in water (1 Omi) was added dropwise so that temperature did not exceed 0'. Stirring was continued for 30min. The resulting suspension was filtered to remove starting material and the filtrate added in a few portions to a solution of 5 stannous chloride dihydrate (1 3.5g) in hydrochloric acid (1 5mi) at - 20' and warmed to ambient temperature. The solid that separated was filtered off and recrystallised from hot methanol (1 00mi) to give the title compound as white plates (0.39g) m.p. 192-193. The mother liquors afforded a second crop (0.52g).

(d) 3-(2-Aminoethyi)-N-(phenyimethyl)-1H-indole-5-methanesulphonamide, compound with crea tinine, sulphuric acid and water (1: 1: 1: 1. 2) A solution of the product of stage (c) (0.47) and 4-chlorobutanal dimethylacetal (0.24g) in ethanot (50mi) and water (1 Orni) was heated at reflux for 4h. Solvent was evaporated and the residual oil purified by column chromatography (F) which afforded the tryptamine slightly impure as an oil (0. 34g). A second chromatography (K) gave pure free base as an oil (0. 1 g) which was taken up in hot ethanol (8mi) and water (1 mi) and treated with a solution of creatinine and sulphuric acid (1: 1,2N,O. 1 5mi). The salt which crystallised on cooling was filtered off, dried in vacuo at 60 and the title compound obtained as an off-white powder (0.125g), m.p. 230-231.

Analysis Found: CA5.9; H,5.7; W14.6; C,8H2,N302S,C4H7N3O.H2S04.1.2H20 requires: C,45.7; H,5.3; N,14.2% T.I.c. (K) Rf 0.41 Example 10

3-(2-Aminoethyl)-N-phenyi-1H-indole-5-methanesulphonamide, compound with creatinine, sul phuric acid and water (1: 1: 1: 1) (a) 4-Amino-N-phenylbenzenemethanesulphonamide A solution of 4-Nitro-N-phenyibenzenemethanesulphonamide (11.09), in ethyl acetate (400mi) 30 was hydrogenated at room temperature and pressure over pre-reduced 10% palladium oxide on charcoal (1.0g, 50% paste with water) for 4h until hydrogen uptake ceased (2.71). Methanol (400mi) was added, the catalyst filtered off, and the filtrate evaporated in vacuo to give the title compound as a white solid (8.98g), m.p. 180-182.

(b) 4-Hydrazino-N-phenylbenzenemethanesulphonamide, hydrochloride By a procedure similar to that described in example 9(c), the product of stage (a) (7.4g) was diazotised and then reduced with stannous chloride to give the title compound as a fawn solid (2.0g), m.p. 168-170 (from ethanol).

(c) 3-(2-Aminoethyi)-N-phenyl-1 H -indole-5-methanesulphonamide, compound with creatinine, sulphuric acid and water (1: 1: 1: 1) By a procedure similar to that described in example 9(d), the product of stage (b) (0.59) was condensed with 4-chlorobutanal dimethyl acetal (0.259) to give the tryptamine as an oil. The oil was dissolved in a hot mixture of ethanol (40mi) and water (5mi) and an aqueous solution of 45 creatinine and sulphuric acid (1A, 2M, 0.9mi) added. Filtration of the cooled mixture acid gave the title compound as a pale fawn solid (0. 3g), m.p. 198200.

Analysis Found: CA5.6; H,5A W14.8.

C,7H,,N302S.C4H,N3O.H20,.H20 requires C,45.2; H,5.4; N, 15.0% T.I.c. (L) Rf 0.4 Example 11 3-(2-Aminoethyi)-N-cyclohexyl- 1H -indole-5methanesulphonamide, compound with creatinine, sulphuric acid, and water (1: 1: 1: 1) (a) N-Cyclohexyl-4-nitrobenzenemethanesulphonamide By a procedure similar to that described in example 9(a) 4-nitro-benzenemethanesulphonyl chloride (0.39) was treated with cyclohexylamine (0.36mi) to give the title compound (0.25g) m.p. 170-171 (from ethanol).

(b) 4-Amino-N-cyclohexyibenzenemethanesulphonamide By a procedure similar to that decribed in example 9(b) the product of stage (a) (6.49) was hydrogenated to give the title compound (5.0g), m.p. 141-143 (from isopropanol).

(c) N-Cyclohexyl-4-hydrazinobenzenemethanesulphonamide, hydrochloride By a procedure similar to that described in example 9(c) the product of stage (b) (1.09) was 65 1 11 GB 2 124 21 OA 11 diazotised and then reduced with stannous chloride to give title compound as a white solid (0.25g), m.p. 158-160', 90% pure. T.I.c. (N) Rf 0.16.

(d) 3-(2-Aminoethyl)-N-cyclohexyl-1H-indole-5-methanesulphonamide, compound with creatinine, sulphuric acid, and water (1: 1: 1: 1) By a procedure similar to that described in example 9(d) the product of stage (c) (0. 199) was condensed with 4-chlorobutanal dimethyl acetal (0.099) and flash chromatographed (Kieselgel 9385) (B) to give the tryptamine as a colourless glass (0. 1 g) which was dissolved in a hot mixture of ethanol (gmi) and water (1 mi) and treated with a solution of creatinine and sulphuric acid (2M, 1: 1, 0. 1 5mi). On cooling and scratching the title compound was deposited as a plate cream-coloured crystalline solid (0. 1 g), m.p. 218-221 (dec) after drying in vacuo over P20. for 10h at 60.

Analysis Found C,44.7; H,6.1; N,14.7; C17H2r,N302SC4H7N3O.H2S04.H20 requiresC,44.7; H,6.4; NA4.9% Example 12

3-(2-Aminoethyi)-N,N-dimethyi-1H-indole-5-methanesulphonamide, maleate.

(a) 4-Amino-NN-dimethyibenzenemethanesulphonamide.

A suspsension of N, N-dimethyi-4-nitrobenzenemethanesulphonamide (4.29) in methanol 20 (300mi) was hydrogenated over pre-reduced 10% palladium oxide on charcoal (1 g) at atmospheric pressure and temperature. Hydrogen uptake was complete in 1 h. The catalyst was filtered off (Hyflo), washed with ethyl acetate (400mi), the solvent evaporated and the title compound obtained as a cream solid (3.3g), m.p. 151-2.

(b) 4-hydrazino-N,N-dimethylbenzenemethanesulphonamide, hydrochloride. To a stirred suspension of the product of stage (a) (3.2g) in conc. hydrochloric acid (35mi) and water (1 7mi) at - 5 (ice-salt bath) was added a solution of sodium nitrate (1. 1 g) in water (3mi) at such a rate that the temperature did not exceed 0. After stirring for 1 Ornin, the yellow solution was added to a solution of stannous chloride dihydrate (1 7g) in conc. hydrochloric acid 30 (40mi) at - 10 at such a rate that the temperature did not exceed WC. Stirring was continued for 1 h at room temperature, the solid was collected by filtration, washed with ether (500mi) and dried in vacuo at room temperature. The crude product (2.95g) was crystallised from hot ethanol (40mi) and methanol (20mi) to give the title compound as a white solid (1.6g), m.p.

155-6.

(c) 3-(2-Aminoethyl)-N,N-dimethyl-lH-indole-5-methanesulphonamide, maleate.

A solution of the product of stage (b) (1 g) and 4-chlorobutanal, dimethyl acetal (0. 7g) in ethanol:water (5:1, 50ml) was heated at reflux for 1 h 40min. The cooled solution was evaporated to dryness under reduced pressure. The red-brown residue was purified by column 40 chromatography (B) to give the tryptamine as an oil (0. 1 3g). A solution of this in ethanol (5ml) was treated with maleic acid (0.054g) and then concentrated to a foam which was triturated with ether and dried in vacuo at 80 to give the title compound as a hygroscopic solid (0.06g).

Analysis Found: C,51.6;K6.0X 10. 1.

C13H19N302S,C4H404 requires C,51.4;H,5.8;N,10.6%.

T.I.c. (F) Rf 0.34.

In another experiment a hot solution of the tryptamine (0.079) in ethanokwater (8A, 6mi) was treated with a solution of creatinine and sulphuric acid (1: 1,0. 1 25mi, 2N) added in one portion 50 and on cooling, the title compound crystallised as the creatinine sulphate adduct (85m9), m.p.

197-198, dried at 60.

Analysis Found: C, 40.3; H, 5. 7; N, 16. 1.

C13H19N302S,C4H7N3O.H2S04.H20 Requires C,40.0;H,5.9;N,16.5%.

Example 13 3-(2-Aminoethyl)-N-(2-phenylethyl)- 1 H -indole-5methanesulphonamide, hydrochloride quarter hydrate.

(a) 4-Nitro-N-(2-phenylethyi)benzenemethanesulphonamide. By a procedure similar to that described in example 9(a) 4-nitrobenzenemethanesulphonyl chloride (6.0g) was condensed with 2-phenylethylamine (Bml) to give the title compound as a light brown solid (7.5g), m.p. 101-103.

(b) 4-Amino-N-(2-phenylethyl)benzenemethanesulphonamide.

12 GB2124210A 12 By a procedure similar to that described in example 9(b) the product of stage (a) (7.0g) was hydrogenated in ethanol to give the title compound as a white solid (6.0g), m.p. 123-125 (from ethanol).

(c) 4-Hydrazino-N-(2-phenylethyi)benzenemethanesulphonamide, hydrochloride.

By a procedure similar to that described in example 9(c) the product of stage (b) (4g) was diazotised and reduced to give the title compound (3. 0g), m.p. 160-163 (from ethanol).

(d) 3-(2-Aminoethyl)-N-(2-phenylethyi)- 1 H -indole-5-methanesulphonamide, hydrochoride, quarter hydrate. By a procedure similar to that described in example 9(d) the product of stage (c) (2.0g) was condensed with 4-chlorobutanal dimethyl acetal (1.09) and flash chromatographed (Kieselgel 9 385) to give the tryptamine as a yellow oil. The oil was dissolved in methanol (1 Omi) acidified with ethanolic hydrogen chloride (ca 2mi) and diluted with ether (200mi). The ether was decanted off the resulting gum, and replaced with more dry ether (200mi). Scratching caused 15 the gum to crystallise, and the resulting solid was filtered off, and dried in vacuo to give the title compound as a cream solid (0.659), m.p. 115-11 WC.

Analysis Found: C, 5 7.2 5; H, 6.2; N, 10. 3.

C,9H23N302S.HCI.0.25H20 requires c,57.3;H,6.2;N,10.5%. T.I.c. (J) Rf 0.4 Example 14

3-[2-Aminoethvi)-N-t2-Drot)envi)-1H-indole-5-methanesulphonamide, hydrochloride.

(a) 4-Nitro-N-(2-propenyi)benzenemethanesulphonamide.

4-Nitrophenylmethanesulphonyl chloride (5.0g) was added dropwise in dry dichloromethane (50ml) to a stirred solution of allylamine (3.3ml) in dry dichloromethane (50mi) at room temperature under nitrogen over 15min. Stirring was continued for 45min. The mixture was washed with water (3 X 50ml), dried (MgSO,,) and the solvent evaporated to give a very pale 30 yellow solid (5.22g). A sample (0.26g) was recrystallised from ethanol to give the title compound as very pale yellow needles (0. 1 82g), m.p. 118-120.5.

(b) 4-Amino-N-(2-propenyl)benzenemethanesulphonamide, hydrochloride.

Sodium borohydride (0. 3 7g) in ethanol (1 20mi) was added dropwise over 30min to a stirred solution of the product of stage (a) (5.0g) and stannous chloride dihydrate (22g) in ethanol (400ml) at 65 under nitrogen. After stirring at 65' for a further 30min, the mixture was cooled in an ice bath, and iced water (400ml) followed by 5N sodium hydroxide (40mi, to pH 8) were added, giving a milky emulsion. The ethanol was evaporated at reduced pressure, more 5N sodium hydroxide (11 Oml) was added, and the mixture was extracted with ethyl acetate 40 (3 X 250ml). The organic layers were washed with brine, dried (MgS04) and evaporated to give a yellow solid (4.96g). A sample (0.3g) was dissolved in ethanol (1.5ml), and ethanolic hydrogen chloride (ca 3M, 0.6ml) was added giving a pale yellow precipitate which was filtered off and dried in vacuo at 45% to give the title compound as pale yellow crystals (0.239g), m.p.

153.5-155% (c) 4-Hydrazino-N-(2-propenyi)benzenemethanesulphonamide, hydrochloride.

A solution of sodium nitrite (1.06g) in water (2.5mi) was added dropwise to a stirred suspension of the product from stage (b) (3.5g) in 5N hydrochloric acid (28mi) between - 8 and - 3 under nitrogen and stirring was continued at ca - 3 for 80min. The mixture was filtered, and 50 the clear yellow filtrate was added dropwise from an ice-cooled, jacketed dropping funnel to a stirred solution of stannous chloride dihydrate (17.59) in concentrated hydrochloric acid (1 7.5mi) between - 2' and + 1 over 35min. After warming up to 10 over 1 5min, the mixture was filtered, and the residue was washed with concentrated hydrochloric acid (4 X 5mi) and dry ether (4 X 30mi) and dried to give the title compound as a very pale yellow solid 55 (2.449), m.p. 163-166', containing 5% inorganic material.

(d) 3-(2-Aminoethyl)-N-(2-propenyl)-lH-indole-5-methanesulphonamide, hydrochloride.

The product from stage (c) (1.5g) was heated under reflux with 4chlorobutanol dimethyl acetal (0.83g) in 5:1 ethanoi:water (75mi) with stirring under nitrogen for 1.5h. The mixture was 60 poured into 8% aqueous sodium bicarbonate (25mi), and the ethanol was evaporated off at room temperature (vacuum pump). The mixture was extracted with ethyl acetate (4 X 40ml) and the organic layers were washed with brine, dried (MgS04) and evaporated to give a brown oil (1.62g). Further extraction of the aqueous layers with butanone (3 X 40ml), drying (MgS04) and 13 GB 2 124 21 OA evaporation gave a further quantity (0.39) of brown oil. The combined crude products were purified by flash chromatography (Kieselgel 9385, H) to give a pale yellow foam (0.55g). The foam was dissolved in absolute ethanol (2mi), and ethanolic hydrogen chloride (ca 3M, 0.6mi) was added giving a clear solution (pH 3). Addition of ethyl acetate (10mi) followed by dry ether (60mi) gave a white precipitate, which was triturated with dry ether (3 X 70mi), filtered off and dried in vacuo at room temperature, to present the title compound as a powdery white solid (0.484g), m.p. ca 90- 150' which was - dried at 75. T.I.c (L) Rf 0.45.

Analysis Found: C, 503; H, 5. 9; N, 12.3.

C14H19N302S.HO requires Q51.0;H,6AX12.7%.

Example 15

3-(2-Aminoethy/)-N-(l-methylethyl)-lH-indole-5-methanesulphonamide compound with maleic 15 acid (2:3) (a) N-(l-Methylethyl)-4-nitrobenzenemethanesulphonamide By a procedure similar to that described in example 9(a) 4- nitrobenzenemethanesulphonyl chloride (5g) was reacted with isopropylamine (5.63mi) to give the title compound (4.14g) m.p.

146-147 (from ethanol).

(b) 4-Amino-N-(l-methylethyi)benzenamethanesulphonamide By a procedure similar to that described in example 9(b) the product of stage (a) was hydrogenated in ethanol to give the title compound (2.45g) m.p. 105-107 (from isopropanol) (c) 4-Hydrazino-N-(1-methylethyi)benzenemethanesulphonamide, hydrochloride By a procedure similar to that described in example g(c) the product of stage (b) was diazotised and reduced to give the title compound as a white powder (1.59), 79% pure by periodate titration. T.I.c. (A) Rf 0.36.

(d) 3-(2-Aminoethyl)-N-(1 -methylethyl)- 1 H -indole-5methanesulphonamide compound with ma leic acid (22) A mixture of the product of stage (c) (1.5g) and 4-chlorobutanal dimethyl acetal (0.79) ina mixture of ethanol (35mi) and water (5mi) was heated at 50' for 30 min. Ammonium acetate (0.97g) was added and the mixture heated at reflux for 4h. The suspension was then diluted 35 with water (200mi) and the solid removed by filtration. The filtrate was washed with ethyl acetate (3 X 50mi) and the washings discarded. The aqueous layer was basified by the addition of solid potassium carbonate (30g) and the mixture extracted with ethyl acetate (4 X 50mi), the extracts were dried (Na2S04) and evaporated under reduced pressure. The residual oil was chromatographed (B) and the tryptamine (0.2g) was dissolved in ethanol (5mi), maleic acid 40 (78.5m9) in ethanol (5mi) was added and the solution reduced to dryness to give a pale brown gum. Trituration with isopropanol (3 X 5mi) gave the title compound as a pale brown powder (0.219) m.p. 150-152'.

Analysis Found: Q50.9; H,5.9; W8.6.

C14H2,N302S.1.5C4H404 requires Q51.2; H,5.8; N,9.0% T.I.c (H) Rf 0.30 Example 16

3-(2-Aminoethyl)-N-ethyi-1H-indole-5-methanesulphonamide, maleate, hernihydrate compound with diethyl ether (10: 10: 5: 1) (a) 4-Amino-NEthylbenzenemethanesulphonamide A solution of N-ethyi-4nitrobenzenemethanesulphonamide (4.359) in warm ethanol (1 25mi) was added to 10% palladium oxide on carbon (0.759, 50% aqueous paste) prereduced in ethanol (25mi) and hydrogenated at atmospheric pressure. Hydrogen uptake (1 400mi) ceased after 20 minutes. The suspension was filtered and the catalyst was washed with methanol (1 00mi) and ethanol (1 00mi). Evaporation of the combined filtrate and washings produced a grey solid (2.0g) which was crystallised from isopropanol (1 20mi) to the present the title compound as cream micro needles (1.48g), m.p. 161-164.

(b) N-Ethyl-4-hydrazinobenzenemethanesulphonamide hydrochloride Sodium nitrate (1.01) in water (1 2mi) was slowly added to a stirred suspenssion at - 5 of the finely ground product of stage (a) (3.14g) in concentrated hydrochloric acid (30mi) keeping the temperature below 0. The resulting mixture was stirred at - 5 for 1 5min. then slowly added 65 14 GB 2 124 21 OA 14 to a cold ( - 5) stirred solution of stannous chloride (16.529) in concentrated hydrochloric acid (30mi) keeping the solution below W. After allowing the mixture to warm up to room temperature over a period of 1 h, the suspension was filtered and the solid washed with ether to give the title compound as a white aolid (2.06g), m.p. 169-170.

(c) 3-(2-Aminoethyi)-N-ethyl-1H-indole-5-methanesulphonamide maleate hernihydrate compound with diethylether (10: 10: 5: 1) A solution of the product of stage (b) (0.425g) and 4-chlorobutanal dimethyl acetal (0. 244g) in ethanol-water (5:1) (20mi) was stirred at 50 for 40min. Ammonium acetate (0.7394g) was 10 added and then the pH of the solution adjusted to pH 4 by hydrochloric acid. The resultant solution was heated under reflux for 2h. The pale brown mixture was diluted water (200mi) and washed with ethyl acetate (3 X 1 00mi). The aqueous solution was basified with potassium carbonate (solid) and then extracted with ethyl acetate (4 X 1 00mi). Subsequent evaporation of the dried (M9S04) organic extracts yielded a brown foam (0.38g) which was purified by chromatography (N) to give the tryptamine as a pale brown gum (0. 1 435g). A solution of the base (0. 1 435g, in methanol (2mi) was treated with maleic acid (0.0591 6g) in methanol (2mi). Subsequent evaporation of the clear solution under reduced pressure gave a pale brown gum which was triturated with anhydrous diethyl ether to present the title compound as a cream powder (0.09g), m.p. 139142 T.I.c. (H) Rf 0.4 Analysis Found: Q50.1;W5.8X9.4; C13H19N302SC4H4040.5H20011C4H,00 C,50.5:H,6.1;N,10.2% Example 17 3-(2-Aminoethyl)-lH-indole-5-methanesulphonamide, hydrochloride.

(a) 4-Aminobenzenemethanesulphonamide.

A suspension of 4-nitrobenzenemethanesulphonamide (7.11 g) and 5% palladium oxide on charcoal (1.4g) in ethanol (1. 11) was hydrogenated at room temperature and pressure. The reaction was terminated after 2.51 of hydrogen had been absorbed and the catalyst was removed by filtration. The filtrate was concentrated to give the title compound as a solid (4.72g). Recrystallisation of a sample from ethanol gave analytically pure material m.p. 166 35 (bubbles).

(b) 4-Hydrazinobenzenemethanesulphonamide hydrochloride.

A solution of sodium nitrate (1. 1 2g) in water (1 Omi) was added dropwise with stirring over a period of 1 Omin to a paste of the product of stage (a) (3.0g) in conc. hydrochloric acid (4.8mi) 40 at 0 to - 5. The mixture was chilled to - 5' and added in portions over 1 Omin to a vigorously stirred solution of sodium sulphate (5.029) and sodium acetate (5g) in water (40mi) at 0 to - 5. After 20min the mixture was allowed to warm to room temperature over 1 h and was then heated at 75-85 for 1 h. The solution was filtered and acidified with conc. hydrochloric acid (5.2mi) and heated at 80-85 and then more conc. hydrochloric acid (28mi) was added. The 45 solution was then chilled and the title compound separated as a cream solid (2.1 5g), which was used in the next stage without further purification.

T.I.c. methanol-ethyl acetate, (M) Rf 0.6, 0.9 (minor).

(c) 3-[2-(1,3-Dihydro-1,3-dioxo-2H-isoindol-2-yl)ethyll-1H-indole-5methanesulph onamide. 50 A mixture of 2-(4,4-diethoxybutyi)-1 H-isoindole-1,3(2H)-dione (0.589), the product of stage (b) (0.51) and 50% aqueous acetic acid (20mi) was warmed to give a yellow solution which was then boiled in an atmosphere of nitrogen for 2h. The mixture was cooled and extracted with ethyl acetate (5 X 25mi). The extracts were washed with water (3 X 30mi), dried (Na2S04) and concentrated to a gum which on trituration with ether gave a cream solid (0.57g). This was chromatographed eluting with ethyl acetate to give the product as a gum which solidified on trituration with ether. This material (0.299) was absorbed from acetone onto a PLC plate (Merck Kieselgel 60 F254, 20 X 20cm) and eluted twice with ethyl acetate- cyclohexane (1:1). The pure indole was isolated from the stationary phase by Soxhiet extraction with ether for a day.

Removal of the solvent gave a gum which in trituration with ethyl acetate gave the title 60 compound as a cream solid, m.p. 186-188 (32mg).

(d) 3-(2-Aminoethyl)-lH-indole-5-methanesulphonamide, hydrochloride.

The product of stage (c) (0.3g) was taken up in a solution of methylamine in ethanol (38%, 8ml) to give a clear yellow solution which was kept at room temperature for 3h. Solvent was 65 GB 2 124 21 OA 15 removed in vacuo and the residual gum was re-evaporated with ethanol (2 X 8ml), then taken up in methanol (5ml) and filtered. The filtrate was treated with ethereal hydrogen chloride and diluted with ethyl acetate (50ml). A gummy solid separated which was absorbed from methanol onto a PLC plate (Merck Kieselgel 60, 20 X 20cm) and eluted in ethyl acetate-isopropanol water-0.88 ammonia (25:15:8:2). The sulphonamide was extracted from the stationary phase 5 with methanol (6 X 1 Oml). The methanol solution was filtered and concentrated to a gum. This was taken up into ethyl acetate and filtered to remove silica and then treated with ethereal hydrogen chloride. The title compound separated as a cream solid (25mg), m.p. 237-239' (dec.).

Analysis Found: C,,Hl,N302S.HCI requires T.I.c. (L) Rf 0.37.

C,45.5;H,5.6;N,13.5. C, 4 5.6; H, 5.6; N, 14.5 %.

Example 18

3-(2-Aminoethyl)-1H-indole-5-methanesulphonamide, maleate (a) Phenyimethyl [2-[5-[aminosulphonyl)methyll- 1 H-indol-3-yl]ethyll carbamate A solution of the product of example 17 (c) (1.38g) and hydrazine hydrate (0.72mi) in ethanol (80mi) and ethyl acetate (20mi) was heated at reflux for 2h. The mixture was cooled to room temperature and the resulting yellow solid filtered off. The filtrate was washed with saturated 20 potassium carbonate (2 X 30mi), the solvent evaporated and the crude free base which was identical with the product of example 17(d) was used in the next step without further purification.

A suspension of the base in dilute sodium carbonate (2N; 50mi) was treated with benzyi chloroformate (1 mi) and stirred at room temperature for 1 h. The resulting suspension was 25 extracted with ethyl acetate (4 X 30mi), the organic layer dried (MgSOJ, solvent evaporated and the crude product, a black oil, (1.79) was purified by column chromatography (M) to give an oil (0.6g). Crystallisation from chloroform (40mi) gave the title compound as a white solid (0.4g) m.p. 74-75.

(b) 3-(2-Aminoethyl)-1H-indole-5-methanesulphonamide, maleate The product of stage (a) (0. 1 4g) was hydrogenated in methanol (1 Orni) over prereduced 10% palladium oxide on carbon (0.08g) until hydrogen uptake ceased. The catalyst was removed by filtration and the filtrate concentrated. The residue was purified by chromatography (F) to give the tryptamine as an oil (0.057g) which was treated with maleic acid (0. 0269) in ethanol (5m]) 35 and methanol (1 mi). Solvent was evaporated and the residual oil crystallised from absolute ethanol (2mi) to give the title compound as a light brown solid (0.03g) m. p. 174-175.

Analysis Found: CA8.6; H,5.2; K10.7.

C111-115N302S.C.1---1404requires Q48.8; H,5.2; N, 11.4%.

T.I.c (L) Rf 0.37 Example 19

3-[2-(Methylamino)ethyij-lH-indole-5-methanesulphonamide, maleate.

(a) 4-[2-(3-Cyanopropylidene)hydrazino]benzenemethanesulphonamide- A thick suspension of the product of example 1 7(b) (0.32g) in water (2ml) was stirred at room temperature and a solution of 3-cyanopropanal dimethyl acetal (0.26g) in methanol (1 ml) was added followed by addition of hydrochloric acid (2N; 5 drops). Stirring was continued for 3h.

The resulting off-white solid was filtered off and dried in vacuo at 20 to give the title compound (0.31g), m.p. 175-176% (b) 3-(Cyanomethyl)-1H-indole-5-methanesulphonamide.

A suspension of the product of stage (a) (3.1 g) and polyphosphate ester (30g) in chloroform (60mi) was heated at reflux for 1 Omin then poured onto ice and extracted with chloroform (4 X 20mi). The combined organic extracts were dried, the solvent evaporated and the resulting oil purified by chromatography (G) to give the title compound as a yellow solid (0.32g), m.p.

184-185.

(c) 3-[2-(Methylamino)ethyi]-1H-indole-5-methanesulphonamide, maleate. A solution of the product of stage (b) (0.21 g) in ethanolic methylamine (20mi; 30% w/w) was hydrogenated over pre-reduced 10% palladium oxide on charcoal (0.4) (as a 50% aqueous paste) in ethanol (1 Omi) at room temperature and atmospheric pressure for 3h. The catalyst was removed by filtration (Hyflo) and the filtrate concentrated to an oil. 6 5 Chromatography (N) and (0) gave the free base as a white solid (0. 1 8g). This was dissolved in 65 16 GB2124210A 16 hot ethanol (1 0ml) and a solution of maleic acid (0. 1 g) in ethanol (3ml) was added. Ether (1 Oml) was added until a cloudy solution resulted. On cooling the title compound deposited as a cream powder (75mg), m.p. 153-154.

Analysis Found: C, 50. 0; H. 5.4; N, 10. 8.

C12H17N302S.C4H404 requires C,50.4;H,5.0Xl 1.0%.

T.I.c. (0) Rf 0.27.

Example 20

3-[2-(Ethylamine)ethyll-1H-indole-5-methanesulphonamide, hydrochloride, hemihydrate, compound with ethanol (5:5:2:5: 1) A solution of the product of example 1 9(b) (0.32g) in ethanolic ethylamine (30mi; 33%w/w) was hydrogenated over pre-reduced 10% palladium oxide on charcoal (0.4g, 50% aqueous paste) in ethanol (10mi) at room temperature and atmospheric pressure overnight. The catalyst was removed by filtration (Hyflo) and the filtrate concentrated to an oil (0.30g). Chromatography (0) gave the free base as a foam (0.28g). A solution of the tryptamine (0.28g) in absolute ethanol (1 Omi) and methanol (1 Orni) was treated with ethanolic hydrogen chloride (ice cooling) to pH 1, ether (20mi) was added and the resulting suspension was left in the fridge overnight.

The title compound was filtered off as a white powder (0.249) m.p. 143144.

Analysis Found: CA8.1; H,6.3; W12.4.

C13H,,N302S.HCl.05H20.0.2C,H,,0 requires C,47.9; H,6.7; N,12.5%.

T.I.c. (0) Rf 0.48.

Example 21

3-[2-(Dimethylamino)ethyll-1H-indole-5-methanesulphonamide, hydrochloride, compound with isopropanol (10: 10: 1: 5) A solution of the product of example 19 (b) (0.29) in methanolic dimethylamine (1A, 20mi was 30 hydrogenated over pre-reduced 10% palladium oxide on charcoal (0.4g, 50% aqueous paste) in methanol (1 Orni) at room temperature and atmospheric pressure for 5h. The catalyst was removed by filtration (hyflo) and the filtrate was concentrated to an oil. Chromatography (B) gave the tryptamine as a white foam (0. 1 6g). Ethanolic hydrogen chloride was added dropwise to a cold solution (ice bath) of the free base in isopropanol (4mi) (until pH4) and the title 35 compound was precipitated as a white powder (0.14g) m.p. 237-239.

Analysis Found: CAT1; H,6.5; W12.6.

C13H,,N3 X 2S.I-IC1.0.1 5C31-1.0 requires CA9.4; H,6.5; W12.9%.

T.I.c. (B) Rf 0.23 Example 22

N-Methyi-3-[2-(methylamino)ethyil-1H-indole-5-methanesulphonamide, compound with maleic acid and ethanol (10: 10: 1) A solution of the product of example 2(b) (0.9g) in dry tetrahydrofuran (20mi) was added to a suspension of lithium aluminium hydride (0.9g) in dry tetrahydrofuran (100mi) and heated for 2h at reflux. The resulting suspension was cooled treated with saturated solution of potassium carbonate (ice cooling), extracted with methanol ( X 25mi) and the extract concentrated. The residual oil was purified by column chromatography (K) to give the tryptamine as an oil (0.37g). 50 This was dissolved in absolute ethanol (5mi) and treated with ethanolic maleic acid (0.5M; 2.6mi). A sticky precipitate separated. Methanol was added dropwise until a clear solution resulted which was then concentrated under reduced pressure to approx. 1 mi and the title compound crystallised as an off-white solid (0.29) m.p. 123-124.

Analysis Found: C,51.0; H,5.8; K10.1.

C13H19N302S.C,H,O,.0.'C2H,0 requires Q51.4; H,5.9; N,10.45%.

T.I.c. (K) Rf 0.32 - Example 23

N-Methyl-3-[2-(methylamino)ethyl]- 1H -indole-5-methanesulphonamide (a) 3-(2-Chloroethyi)-N-methyi-1H-indole-5-methanesulphonamide.

A solution of the product of example 6(a) (0.259) in chloroform (3mi) was added to a solution of polyphosphate ester (2.5g) in chloroform (2m[) and the solution wa heated under reflux with 65 17 GB 2 124 21 OA 17 stirring for 5min. The solution became dark yellow. It was then cooled and poured onto ice (20g) and chloroform (5mi) and stirred. The aqueous phase was brought to pH 8 by the addition of sodium bicarbonate and the organic layer was collected. The aqueous layer was extracted with chloroform (4 X 20mi) and the extracts dried (Na2SO4). Removal of the solvent in vacuo gave the crude 3-chloroethyl indole as a light brown viscous oil (0.677g) which was used in the next experiment without further purification. T.I.c. (P) Rf 0.58 (major), Rf 0.64 (minor).

(b) N-Methyi-3-[2-(methylamino)ethyil-1H-indole-5-methanesulphonamide.

The Product of stage (a) (0.677g) was taken up in 33% methylamine in ethanol (25mi) and 10 heated in a steel autoclave at 80-90 for 16h. The dark yellow solution was concentrated to a light brown oil (1.25g) which was chromatographed (J) to give the title compound (0.039g) as a light yellow glass which was shown by n.m.r. and fl.c. (L) Rf 0.4 to be identical with the product of Example 22.

Example 24

3-(2-Aminoethyi)-1 H -indole-5-methanesulphonamide hemisuccinate.

A mixture of the product from Example 17 stage (b) (1 0.0g) and 4chlorobutanal dimethyl acetal (6.239) in ethanol (260mi) and water (53mi) was stirred at 50 for 1.5h. Ammonium acetate (8.68g) was then added and the resultant milk was heated to reflux and stirred for 3.5h. The 20 mixture was then cooled and reduced in volume in vacuo to ca. 30mi. The orange residue was partitioned between 5N potassium carbonate (800mi) and ethyl acetate (3 X 500M1). The combined organic extracts were then washed with 5N potassium carbonate (200mi) and water.

(200mi). The organic solution was then dried (Na2SO4) and concentrated in vacuo. The residual brown oil was chromatographed (J) to give a brown oil which slowly crystallised (2.12g).

A portion of this material (1.0g) was dissolved in boiling ethanol (25mi), and added to a hot solution of succinic acid (0.22g) in ethanol (1 5mi). The solid that crystallised on cooling was filtered off, washed with ethanol (3 X 1 Omi) and dried in vacuo at 35 for 6h to give the title sulphonamide as fawn microcrystals (1. 189), m.p. 230-231.5' (foams). This product was shown by n.m.r. and fl.c. (J, Rf 0. 17) to be identical with the product from Example 17 (d). 30 Example 25

3-[2-(Methylamino)ethyll-N-methyl-1H-indole-5-methanesulphonamide, maleate quarter hydrate.

(a) 3-[2-(Formyiamino)ethyll-N-methyl-1H-indole-5-methanesulphonamide A mixture of the product of example 1 (c) as the free base (0.534g) and Nformyl imidazole 35 (0.211 g) was stirred in dry tetrahydrofuran (30mi) for 30min. After removal of the solvent by evaporation under reduced pressure, the residue was partitioned between chloroform (50mi) and 2N hydrochloric acid (50mi). The aqueous phase was basified using 2N sodium hydroxide (pH 9) and was extracted with ethyl acetate (2 X 50mi). The combined organic extracts were dried (Na2SO4) and evaporated under reduced pressure yielding a pale yellow gum. This was chromatographed (J).to give the title compound as a colourless gum (0.35g). T.I.c. (J) Rf 0.81.

(b) 3-[2-(Methylamino)ethyll-N-methyl-1H-indole-5-methanesulphonamide, maleate, quarter hy drate.

To a stirred suspension of lithium aluminium hydride (0.77g) in dry tetrahydrofuran (5rni) in a stream of nitrogen was added a solution of the product of stage (a) (0. 3g) in dry tetrahydrofuran (1 Omi). The suspension was heated under reflux for 5h. Water (1 mi) in tetrahydrofuran (9mi) was added to the ice cold mixture and the suspension was filtered through a pad of---hyflo---.

Evaporation of the filtrate gave a pale yellow gum which was chromatographed (J) to give the 50 tryptamine as a colourless gum (0. 159). This was dissolved in hot 2- propanol (2mi) and a solution of maleic acid (0.0629) in ethanol (1 mi) was added. On cooling the title compound deposited as an off-white powder (0. 1 8g), m.p. 122-124, identical with the product of example 22.

Example 26

3-[2-(Ethylamino)ethyll-N-methyl- 1H -indole-5-methanesulphonamide compound with creatinine and sulphuric acid (1: 1: 1).

A mixture of the product of example 7 (0.2g) and acetaidehyde (0.044g). was stirred in methanol (1 Orni) for 1 5min. To the pale yellow solution was added sodium cyanoborohydride 60 (0.062g) and the mixture was stirred at room temperature for 1 h. 2H Hydrochloric acid (2mi) was added and the volume of the solution was reduced to about 2mi by evaporation under reduced pressure. Water (20mi) was added and the solution was washed with ethyl acetate (25mi). The phases were separated, potassium carbonate (59) was added to the aqueous phase which was then extracted with ethyl acetate (2 X 25mi). Evaporation of the dried (Na2SO4) 65 18 GB2124210A 18 combined organic extracts gave a pale yellow gum which was chromatographed (J) to give the product as a colourless gum (0.08g). This was dissolved in ethanol (4m]) containing water (0.5mi) and an aqueous solution of creatinine and sulphuric acid (1A, 2M, 0.14mi) was added. On o.ooling the title compound deposited as a white powder (0.089g), m.p. 197-198.

Analysis Found: C,42.6;H,5.9;N,16.5.

C14H2,N302S.C4H,N3O.H2S04 requires C,423;1-1,6.0;N,16.6%.

T.I.c. (J) Rf 0.37.

Example 2 7 3-(3-Aminopropyl)-N-methyl-1H-indole-5-methanesulphonamide, compound with hydrogen chloride, water and ether (100: 100:85: 11). (a) 2(5,5-Dimethoxypentyl)-1H-isoindole-1,3(2H)-dione. A mixture of potassium phthalimide (0.48g) and 5-bromopentanal dimethyl acetal (0.50g) in dry dimethylformamide (3mi) was stirred at 90 for 5h and then allowed to cool. The resultant 15 yellow suspension was then partitioned between water (30mi) and ethyl acetate (3 X 30mi). The combined organic extracts were then dried (Na2SO4) and concentrated in vauco. The residual pale yellow oil was purified by flash chromatography (Kieselgel 9385, ether) to give the title compound as a white solid (0.33g), m.p. 34.5-37.

(b) 3-[3-(1,3-Dihydro-1,3-dioxo-2H-isoindol-2-yi)propyl]-N-methyi-1Hindole-5-me thanesulpho- namide.

A suspension of the product from stage (a) (2.559) and the product from Example 1 (b) (2.509) in 10% aqueous acetic acid (200mi) was stirred at room temperature for jh and then at reflux for 1 1h. The yellow gummy suspension was allowed to cool and was then extracted with ethyl 25 acetate (3 X 200mi), dried (Na2SOJ and concentrated in vacuo to give an orange foam (3.59g).

This material was used in stage (C). A portion of this foam (0.50g) was chromatographed (G) to give the impure title sulphonamide as an orange foam which failed to crystallised from common organic solvents (0.14g), m.p. 58-66.

T.I.c. Rf 0.37 (G) (c) 3-(3-Aminopropyl)-N-methyl-lH-indole-5-methanesulphonamide, compound with hydrogen chloride, water and ether (100: 100:85: 11). Hydrazine hydrate (3.Oml) was added to a stirred, refluxing suspension of the product from stage (b) (2.90g) in ethanol (90ml) and stirring was continued for 3h. The cooled yellow suspension was evaporated in vacuo and the residual yellow solid was partitioned between 2N sodium bicarbonate (1 50ml) and ethyl acetate (3 X 1 50ml). The combined organic solutions were then dried (Na2SO4) and evaporated in vacuo. The residual yellow foam (1.06) was chromatographed (J) to give an orange gum (0.45g). 40 A portion of this gum (0.39g) was dissolved in absolute ethanol (5ml) and ethanolic hydrogen 40 chloride (1 ml) was added. The stirred solution was diluted with dry ether (ca 80ml) and the precipitated solid was filtered off, washed with dry ether (4 X 15ml) and dried. The solid was reprecipitated three times from absolute ethanol (ca 1 5ml) to give the title salt as a hygroscopic brown solid (0.085g) m.p. 121-125 which slowly turned to a gum.

T.I.c.. (J) Rf 0.2.

* Analysis Found: C, 4 7.13; H, 6.7; N, 12.3.

C13H19N302S.HCI.0.85H20.0.1 1 C41-1100 requires C,47.3;1-1,6.7;N, 12.3%.

Example 28 Phenyimethyl [2-[5-[[(methylamino)sulphonyllmethyll- 1H-indol3-yllethyll carbamate. Sodium hydride (80% in oil, 13mg) was added to a stirred, ice cooled solution of the product from Example 18 stage (a) (1 50rng) in dry dimethylformamide (3mi) under nitrogen. The suspension was stirred at room temperature for 1h and then cooled in ice. Methyl iodide (0.03mi) was added and the solution stirred at room temperature for 7h with further methyl iodide (.03mi) added after 3h. The solution was partitioned between water (30mi) and ethyl acetate (4 X 20mi). The combined organic extracts were then washed with water (4 X 20mi), dried (Na2SO4) and concentrated in vacuo. The residual brown oil (1 40m9) was chromato- graphed (E) to give the title carbamate as a brown oil (1 6mg). This product was shown by n.m.r. and fl.c. (E, Rf 0.35) to be identical with the product of Example 2(b).

Example 29 3-(2-Aminoethyl)-N-methyl- 1 H indole-5-methanesulphonamide To a solution of the product of example 5(b) (0. 1 g) and cobaltous chloride hexahydrate (0. 1 9g) 65 19 GB2124210A 19 in ethanol (5mi) was added sodium borohydride (0. 159) and the resulting suspension was heated at reflux for 1 h. It was poured into dilute hydrochloric acid (2N, 1 Omi). T.I.c. (F) showed the solution contained a component Rf 0.26 identical with that of a sample of the product of Example 1 (c).

Example 30 N-Methyl-3-[2-(phenylmethylideneamino)ethyl]- 1H -indole-5methanesulphonamide compound with water and ether (4: 1: 1). A mixture of the product of example 1(c) as the free base (0.536g) benzaldehyde (0. 232g) and 3A molecular sieves (3g) in ethanol (20ml) was boiled under reflux for 3h. The solution was 10 then stirred at room temperature for 1 h and filtered through hyflo. The filtrate was concentrated and the residue triturated under ether (25ml) to give the title compound as an off-white powder (0.6g), m.p. 130-132% Analysis Found: C,63.4;h,6.0:N,1 1.1.

C,,H,,N302S.O.25H,0.025C,H,00 requires C,63.5;H,6.4;N,11.1%.

PHARMACEUTICAL EXAMPLES Tablets

These may be prepared by the normal methods such as wet granulation or direct compres- 20 sion.

A. Direct Compression mgItablet

Active ingredient 10.0 25 Microcrystalline Cellulose USP 188.5 Magnesium Stearate BP 1.5 Compression weight 200.0 30 The active ingredient is sieved through a suitable sieve, blended with the excipients and compressed using 7mm diameter punches.

Tablets of other strengths may be prepared by altering the compression weight and using punches to suit.

B. Wet Granulation mgItablet

Active ingredient 10.0 Lactose BP 143.5 Starch BP 30.0 40 Pregelatinised Maize Starch BP 15.0 Magnesium Stearate BP 1.5 Compression weight 200.0 45 The active ingredient is sieved through a suitable sieve and blended with lactose, starch and pregelatinised maize starch. Suitable volumes of purified water are added and the powders are granulated. After drying, the granules are screened and blended with the magnesium stearate. The granules are then compressed into tablets using 7mm diameter punches.

C. For Buccal Administration m91tablet

Active ingredient 10.0 Lactose BP 86.8 Sucrose BP 86.7 55 Hydroxypropyl methylcellulose 15.0 Magnesium Stearate BP 1.5 Compression weight 200.0 60 The active ingredient is sieved through a suitable sieve and blended with the lactose, sucrose and hyd roxypropyl methylcel I u lose. Suitable volumes of purified water are added and the powders are granulated. After drying, the granules are screened and blended with the magnesium stearate. The granules are then compressed into tablets using suitable punches.

The tablets may be film-coated with suitable film-forming materials, such as hydroxypropyl 65 GB 2 124 21 OA 20 methylcel 1 u lose, using standard techniques. Alternatively the tablets may be sugar coated.

Capsules Active ingredient Starch 1500 Magnesium Stearate BP Fill Weight mglcapsule 10.0 89.0 1.0 100.0 10 A form of directly compressible starch.

The active ingredient is sieved and blended with the excipients.The mix is filled into size No.2 hard gelatin capsules using suitable machinery. Other doses may be prepared by altering the fill weight and if necessary changing the capsule size to suit.

Syrup Active ingredient Sucrose BP Glycerine BP Buffer Flavour Colour Preservative Distilled water to 5.0M1 mg15mf dose 10.0 2750.0 500.0 as required The active ingredient, buffer, flavour, colour and preservative are dissolved in some of the water and the glycerine is added. The remainder of the water is heated to dissolve the sucrose and is then cooled. The two solutions are combined, adjusted to volume and mixed. The syrup 30 produced is clarified by filtration.

Suppositories Active ingredient 1 O.Orng 3 5 Witepsol H 15 to 1.Og A proprietary grade of Adeps Solidus Ph. Eur.

A suspension of the active ingredient in molten Witepsol is prepared and filled, using suitable machinery, into 1 g size suppository moulds.

Injection for Intravenous Administration % w/v 0.2 as required Water for Injection BP to 100.00 Active ingredient Sodium Chloride BP Sodium chloride may be added to adjust the tonicity of the solution and the Ph may be adjusted, using acid or alkali, to that of optimum stability and/or to facilitate solution of the active ingredient. Alternatively suitable buffer salts may be used.

The solution is prepared, clarified and filled into apporpriate size ampoules sealed by fusion of 50 the glass. The injection is sterilised by heating in an autoclave using one of the acceptable cycles. Alternatively the solution may be sterilised by filtration and filled into sterile ampoules under aseptic conditions. The solution may be packed under an inert atmosphere of nitrogen or other suitable gas. Inhalation Cartridges Active ingredient micronised 1.0 Lactose BP 39.0

mglcartridge The active ingredient is micronised (Microniser is a Registered Trade Mark) in a fluid energy mill to a fine particle size range prior to blending with normal tabletting grade lactose in a high energy mixer. The powder blend is filled into No.3 hard gelatin capsules on a suitable encapsulating machine. The contents of the cartridges are administered using a powder inhaler such as the Glaxo Rotahaler (Registered Trade Mark).

21 GB 2 124 21 OA 21 Metered Dose Pressurised Aerosol mgImetered dose per can Active ingredient 0.500 120.Orng micronised 5 Oleic Acid BP 0.050 12.Orng Trichlorofluoro- 22.250 5.34mg methane BP Dichlorofluoro- 62.2 14.929 methane BP 10 The active ingredient is micronised in a fluid energy mill to a fine particle size range. The oleic acid is mixed with the trichlorofluoromethane at a temperature of 10-1 WC and the pulverized drug is mixed into the solution with a high shear mixer. The suspension is metered into 15 aluminium aerosol cans and suitable metering valves, delivering a metered amount of 85 mg of suspension, are crimped onto the cans and the dichlorodifluoromethane is pressure filled into the cans through the valves.

In the above examples, the active ingredient is preferably 3-(2aminoethyi)-N-methyi-l H indole-5-methanesulphonamide which may be in the form of a physiologically acceptable salt, 20 for example, the hydrochloride or succinate salt.

Claims (13)

1. A compound of the general formula fl):

25 R1R2NSO2CHR3 ARNIR4R5 (1) 1 N 30 H wherein R, represents a hydrogen atom or a C,6alkyl or C3-, alkenyl group; R2 represents a hydrogen atom or a C1-3 alkyl, C3-, alkenyl, aryl, ar(C, Jalkyl or C,-, cycloalkyl 35 group; R3 represents a hydrogen atom or aCl-3 alkyl group; R4 and R,, which may be the same or different each represents a hydrogen atom or a C1-3 alkyl or propenyl group or R, and R. together form an aralkylidene group; and Alk represents an alkylene chain containing two or three carbon atoms which may be 40 unsubstituted or substituted by not more than tWO C1-3 alkyl groups, and physiologically acceptable salts and solvates thereof.

2. A compound according to claim 1, wherein, in the general formula (1) R, represents a hydrogen atom or a C,-, alkyl group and R2 represents a hydrogen atom or a C1-3 alkyl, C3-6 alkenyl or ar(Cl-jalkyl group.

3. A compound according to claim 1 or 2, wherein, in the general formula (1), R3 represents a hydrogen atom.

4. A compound according to any of claims 1 to 3, wherein in the general formula (1), R4 and R,, which may be the same or different, each represents a hydrogen atom or a C1-3 alkyl group.

5. A compound according to claim 1, wherein in the general formula (1) R, represents a hydrogen atom or a C1-3 alkyl group, R2 represents a hydrogen atom or a C, 3 alkyl group, a C3-4 alkenyl group or an ar(C,2)alkyl group; R3 represents a hydrogen atom; and R4 and R5, which may be the same or different, each represents a hydrogen atom or a C1-3 alkyl group.

6. A compound according to claim 5, wherein, in the general formula (1), R, represents a 55 hydrogen atom or a C,-3 alkyl group; R2 represent a C1-3 alkyl group or a C3-4 alkenyl group; R3 and R4 each represents a hydrogen atom; and R. represents a hydrogen atom or C1-3 alkyl group.

7. A compound according to claim 1 selected from 3-(2-methylamino)ethyi)N-methyi-1 Hindole-5-methanesulphqnamide; 3-(2-ami noethyl)-N, N-d i methyl- 1 H-indole-5-methanesulphonamide; and physiologically acceptable salts and solvates thereof.

8. 3-(2-Aminoethyl)-N-methyi-l H-indole-5-methanesulphonamide and its physiologically acceptable salts and solvates.

9. A compound according to any of claims 1 to 8 wherein the physiologically acceptable salt 65 22 GB2124210A 22 is a hydrochloride, hydrobromide, sulphate, fumarate, maleate or succinate.

10. A compound selected from 3-(2-aminoethyi)-N-methyl-1H-indole-5methanesulphonam- ide, hydrochloride; and 3-(2-aminoethyi-N-methyi-l H-indole-5-methanesulphonamide, succinate.

11. A pharmaceutical composition comprising at least one compound of general formula (1) 5 as defined in claim 1 or a physiologically acceptable salt or solvate thereof together with one or more physiologically acceptable carriers or excipients.

12. A process for the preparation of a compound of general formula (1) as defined in claim 1 or a physiologically acceptable salt or solvate thereof which process comprises:

(A) cyclising a compound of general formula (1l):

R1R2NSO2CHR3..', (11) 15 HN=CHCH2AlkO wherein R, R2, R3 and Alk are as defined for general formula (1) and Q is the group NR,11,' (where R, and R are as defined for general formula (1)) or a protected derivative thereof or a 20 leaving group; or reacting a compound of general formula (V):

R1 R2NSO2CHR3:%p, lkY 25 (M). k. 1 : 1 H wherein R, R2, R3 and Alk are as defined for general formula (1) and Y is a readily displaceable 30 group, or a protected derivative thereof, with a compound of formula R,115NH (wherein R, and R5 are as defined for general formula (1)); or (C) reducing a compound of general formula (Vi):

35 R1R2NSO2CHR3, W 40 H wherein R, R2 and R3 are as defined for general formula (1) and W is a group capable of being reduced to give the group AlkNRR, (where R4, R, and Alk are defined for general formula (1)) or a protected derivative thereof, or a salt or protected derivative thereof, and if necessary and/or desired subjecting the compound thus obtained to one or more further reactions comprising (D) (i) converting the resulting compound of general formula (1) or a salt or protected deriviative thereof into another compound of general formula (1): and/or (ii) removing any protecting group or groups; and/or (iii) converting a compound of general formula (1) or a salt thereof into a physiologically acceptable salt or solvate thereof.

13. A process according to claim 12, wherein in step A, a compound of general formula (111) R1 R2NSO2CHR3,, (10 WNH2 wherein R, R2 and R. are as defined for general formula (1) or a salt thereof, is reacted with a compound of formula (IV):

HCOCH2AIkQ (IV) 1 23 GB 2 124 21 OA 23 wherein Alk is as defined for general formula (1) and G is a defined in claim 11 or a salt or a protected derivative thereof.

Printed for Her Majesty's Stationary Office by Burgess & Son (Abingdon) Ltd.-1 984. Published at The Patent Office, 26 Southampton Buildings, London, WC2A 1AY, from which copies may be obtained.