GB2136804A

GB2136804A - Benzoquinolizines

Info

Publication number: GB2136804A
Application number: GB08406283A
Authority: GB
Inventors: Terence James Ward
Original assignee: John Wyeth and Brother Ltd
Current assignee: John Wyeth and Brother Ltd
Priority date: 1983-03-25
Filing date: 1984-03-09
Publication date: 1984-09-26
Also published as: GB2136804B; DE3468877D1; PH20377A; AR240819A1; DK160873B; AU568553B2; DK540684D0; IE57014B1; FI844535A0; CA1247622A; FI844535L; PT78292A; GB8406283D0; AR240937A2; HU199835B; WO1984003702A1; KR910003151B1; PT78292B; DK540684A; ES530973A0

Description

1 GB 2 136 804 A 1

SPECIFICATION

Benzoquinolizines The invention relates to benzoquinolizines, to processes for preparing the benzoquinolizines, to their use and to pharmaceutical compositions containingthem.

The novel compounds of the present invention are 10 benzoquinolizines of the general formula (1) N 2 0 R! N 3 /\ 4 R 0 S A-NIR.SO R 2 2 and their pharmaceutical ly acceptable acid addition salts. In formula (1), R represents hydrogen or lower alky], R' and R2 which may be the same or different each represent hydrogen, lower alkyl, lower alkoxy or halogen, R'and R 4 which may bethe same or differenteach represents loweralkyl, halo(lower)alkyl oraryl and A represents a loweralkylene group having 1 to 3 carbon atoms in the chain between the two N atoms.

Theterm "lower" as used herein meansthatthe radical referred to contains 1 to 6 carbon atoms. preferablysuch radicals contain 1 to 4 carbon atoms. For example, a lower alkyl group may be methyl, ethyl, propyl or butyl. When R' andlor R 2 represent lower alkoxythe group may be, for example, methoxy, ethoxy, propoxy or butoxy. When Wandlor R 2 represents halogen the substituent may be, for example, fluorine, chlorine or bromine. Preferably both R' and R 2 are hydrogen.

The lower alkylene group A may be branched or straight chain provided that there are 1 to 3 carbon atoms in the chain between the two N atoms. For example, the lower alkylene group may be methylene, ethylene, trimethylene or a branched chain group such as ethylethylene or propylene [-CH(CH3). CH2-1. Preferably A is ethylene.

When a radical is preferred to as "aryV' that radical is preferably a phenyl or substituted phenyl group. The substituted phenyl group can be a phenyl group substituted by one or more substituents chosen from, for example, halogen (e.g. chlorine, fluorine or bromine), alkoxy (e.g. lower alkoxy such as methoxy or ethoxy), lower alkyl (e.g. methyl, ethyl, propyl or butyl), alkylenedioxy (e.g. methylenedioxy or ethylenedioxy), nitro, amino, acylamino (particularly lower acylamino), lower alkylamino, diloweralkylamino ortrifluoromethyl.

Examples of R 3 and R 4 are lower alkyl, such as methyl, ethyl, propyl or butyl, aryl such as phenyl or phenyl substituted by one or more of the substituents mentioned above and halo(lower)alky]. The halo substituent in a halo(lower)aikyl group may be fluorine, chlorine, bromine or iodine. More than one halo atom may be present in the halo(lower)alkyl group; if more than one halo atom is preseritthe halo atoms may be on the same carbon atom of th.e (lower)alkyl radical or on differentcarbon atoms (if the radical contains more than one carbon atom). Examples of halo(lower)aikyl groups includejor W example, trifluoromethyl and chloromethyl.

Preferably R % lower alky], e.g. methyl, and R' is lower alkyl (e.g. methyl or propyl) or phenyl.

Preferably R is hydrogen.

The compounds of the invention in which R3 and R4 are the same maybe prepared by reacting a reactive derivative of a suiphonic acid of formula R'S020H (11) (wherein R' has the meanings of R' and R 4 above) with a benzoquinolizine of the general formula R1 1 N R2 (111) H.A.NHR (wherein R, R', R 2 and A are as defined above) and, if 70 required, converting a free base into a pharmaceutically acceptable acid addition salt. The reactive derivative of the sulphonic acid can be, for example, the acid halide or anhydride. Peferably it is the acid halide, i.e. a compound of formula R5S02X (V) (wherein R'is as defined above and X is halogen, preferably chlorine). The reaction is generally carried 80 out under basic conditions.

The starting materials of general formula (111) are novel and may be prepared by reductive amination of a ketone of general formula R1 01 N? R 2 (/T (V1) 0 where R' and R 2 have the meanings given above. For example, the ketone maybe reacted with a diamine of formula NI-127-A-NHR (VII) (where A and R have the meanings given above) and with a hydride transfer agent, e.g. sodium cyanobor- Formulae in the printed specification were reproduced from drawings submitted after the date of filing, in accordance with Rule 20(14) of the Patents Rules 1982.

2 GB 2 136 804 A 2 ohydride. When R in the diamine is a lower alkyl group it maybe necessary to replace the hydrogen on the amino carrying the lower alkyl substituent with a protecting group, such as benzyl and remove the 5 protecting group afterthe reductive amination.

The starting materials of formula (111) may be prepared by an alternative method comprising reductive amination (by reaction with a diamine of formula V[] and e.g. a hydride transfer reagent such as sodium borohydride) of a quaternary salt precursor of the ketone (V1), the quaternary salt having the formula:

R 1 + N-CH CH COCH 2 2 3 2 (where R' and R 2 have the meanings given above and A- is an anion, e.g. halide).

Compounds of the invention in which R'and R' are the same or different maybe prepared by other alternative methods. For example, a benzoquinolizine of general formula (R) P1 R 2 N) IX) 4 HN.MRSO 2 R (wherein A, R, R', R 2 and R 4 have the meanings given above) may be reacted with a reactive derivative of the sulphonic acid of formula (11) above, in an analogous mannerto that described above in connection with the reaction of the benzoquinolizine (111). The benzoquinolizine (IX) is novel and may be prepared by known methods. For example the benzoquinolizine of formula (111) may be selectively sulphonated with the reactive derivative of the sulphonic acid (11) using the requisite amount of reactive derivative forforming the monosulphonamide OX) ratherthan the disulphonamide (1); it may be necessaryto block one of the amine groups in the diamine (111) with a protecting group such as benzyl and removethe protecting group afterthe sulphonation. The benzoquinolizine amination of the ketone (V]) with an amine NH2AN RS02R' (where A, R and R 4 have the meanings given above) and a hydride transfer agent such as sodium borohydride.

Another method of preparing the compounds of the invention comprises reaction of a benzoquinolizine of general formula RI 1 N R 200, QN 3 1/ \ R Son A. NH2 L_ (wherein A, R' and R 2 and R 3 are as deined above) with a reactive derivative of the sulphonic acid of formula (11) in an analogous mannerto that described above in connection with the reaction of the benzo quinolizine (111). The benzoquinolizine starting mate MIO 45 rial of formula (X) is novel and maybe prepared by methods known perse. For example, a benzoquinoli zine of general formula.

RI 2 N3 3 1 xl) R so 2 NH (wherein R', R 2 and R' have the meanings given above) may be reacted with a phthalimido protected 50 haloamine of formula 0 Y-A-N 0 c) (1v) (where A has the meaning given above and Y is halogen, preferably bromine) in presence of a strong base such as sodium hydride or lithium diisopropylamide andthe phthalimido protecting group removed.

Yet another method of preparing the compounds of the invention comprises reaction of a benzoquinolizine of formula (Xl) above with a compound of formula X-A-NRS02R 4 (X11) (where X A and R 4 are as defined above) in presence of a strong base such as sodium hydride or lithium diisopropylamide.

Compounds of the invention in which R is lower alkyl may also be produced by alkylation of the compounds of the invention in which R is hydrogen. Compounds of the invention in which R'andlor R % amino substituted phenyl may be prepared by reduction of compounds in which the R 3 andlor R % nitro substituted phenyl. Similarly compounds in which R3 andlor R 4 is acylamino substituted phenyl may be prepared by acylation of compounds in which R3 andlor R is amino substituted phenyl.

A 3 If in the processes described above the compound of the invention is obtained as an acid addition salt, the free base can be obtained by basifying a solution of the acid addition salt. Conversely, if the product of the process is a free base, an acid addition salt, particularly a pharmaceutical ly acceptable acid addi tion salt may be obtained by dissolving the free base in a suitable organic solvent and treating the solution with an acid, in accordance with conventional proce dures for preparing acid addition salts from base compound.

Examples of acid addition salts are thoseformed from inorganic and organic acids, such as sulphuric, hydrochloric, hydrobromic, phosphoric, tartaric, fumaric, maleic, citric, acetic, formic, methanesul phonic and p-toluenesulphonic acids.

The compounds of the invention possess two asymmetric carbon atoms and hence can exist in various stereochemical forms. In addition they can exist as cis or trans isomers. Itwill be realised that if the starting material of formula (111) is a mixture of isomers the product of formula (1) will also be a mixture of isomers unless the mixture is separated by 65 standard procedures. The preferred compounds of the invention are the trans isomers in which the -N(S02R 3). A.NR.S02R'group is in the equatorial position, i.e. compounds of the general formula (X111) R1 1N 2, H" 3 N(SO R).A.NR.SO R4 H 2 -2 (X111) and the pharmaceutically acceptable acid addition salts thereof. These compounds can be prepared by the methods described above from the corresponding trans isomer starting material.

The present invention also providesthe novel intermediates of general formulae (111), (IX) and (X). Such compounds have the general formula (M) R 1. N R! 2 (XIV) N 1/ \ - 2 z. A NRZ wherein R, W, R 2 and Aare as defined above and Z1 and Z2 are both hydrogen orZ' is hydrogen and Z2 is S02R'(where R'is as defined above) orZ' is S02R 3 (where R 3 is as defined above) and Z2 is hydrogen.

The compounds of the present invention possess pharmacological activity. In particular the compounds possess (x2-adrenoceptor antagonistic activity in warm GB 2 136 804A 3 blooded animals and hence are of value in conditions where antagonism of the (X2-adrenoceptor is desir- able, for example, as antidepressants, in treatment of diabetes and in inhibiting blood platelet aggregation.

The compounds of the invention are tested for (x2-adrenoceptor antagonistic activity on the ratfield stimulated vas deferens preparation using a mod- ification of the method of Drew, Eur. J. Pharmac., 1977,42,123-130. The procedure is described below.

Desheathed vasa deferentia from sexually mature rats were suspended in a 6 mi organ bath in Krebs solution at370 and bubbled with 5% C02 in oxygen.

Platinum ring electrodes were positioned above and belowthetissue forfield stimulation, the stimulus parameters being 0.1 Hz 1 ms pulse width at supramaximal voltage. Twitch responses were recorded isotonically with a 0.5 g loading. Clonidine hydrochloride was used as the oc-adrenoceptor agonist and cumulative concentration-response curves were constructed forthe inhibition of twitch obtained with clonidine in the range 0.125 to 4 ng mi-1. After washing out clonidine, the twitch response quickly recovered and an antagonist as then introduced into the Krebs reservoir. Clonidine concentration-response curveswere repeated 90 min after introduction of the antagonist. The concentration of clonidine producing 50% inhibition of twitch before and after introduction of antagonistwere obtained and the dose-ratio for clonidine was calculated. Various concentrations of the antagonists were used.

These results were plotted in the manner described by Arunlakshana & Schild, Br. J. Pharmac. Che- mother., 1959, 14,48-58 and the values of pA2 and slope were calculated. The compounds of the invention possess potent (X2-adrenoceptor antagonistic activity. For example, N- [(20,11 bot) 1,3,4,6,7,11 b hexahydro - 2W benzo[a]quinolizin - 2 - yll - N- (2 methanesulphonamidoethyl) methanesulphonamide, N- [(2p,l 1 b(x) - 1,3,4,6, 7,11 b- hexahydro -2Hbenzo[alquinolinzin -2-y1] - N-(2- methanesulphonami doethyl) - n- propanesulphonamide and N[(20,11 bot) - 1,3,4,6,7,11 b hexahydro - 2W benzo[al- quinolizin - 2 - yll - N- (2 methanesulphonamidoethyl) benzenesulphonamide, representative compounds of the invention, have been found to have a pA2for 0(2-adrenoceptor antagonistic activity of respectively 7.93,8.29 and 8.12.

The compounds of the invention generally antagonise the (X2-adrenoceptors to a much greater extent than the ocl-adrenoceptors. The (xl antagonistic activity can be evaluated by a number of different methods. One method involves assessing the activity on the isolated anococcygeus muscle of the rat. The method is based on that of Gillespie, Br. J. Pharmac., 1972,45,404-416. In the procedure male rats (250360g) are killed by a blow on the head and bled. The two anococcygeus muscles are removed from their position in the midline of the pelviccavity, where they arisefrom the upper coccygeal vertebrae. The muscles are suspended in 5 mi organ baths in Krebs solution containing 10-4 M ascorbic acid, to prevent drug oxidation. Thetissues are gassed with a 95% oxygen, 5% C02 mixture and maintained at370. Longitudinal muscle contractions are recorded using isotonic transducers. Cumulative dose response 4 GB 2 136 804 A 4 curves are then obtained to phenylephrine or in some cases methoxamine, both agents being presynaptic alpha adrenoceptor agonists. The concentration range of phenylephrine or methoxamine used is 0.02 to 0.8pg. mi-1. The agonist is then washed from the bath and thetest drug added to the bathing medium at a concentration of 1 O'lVI. After30 min equilibration with thetest drug a further agonist dose response curve is obtained. The washing, equilibra- tion and agonists dosing procedures are then repeated using 1 0-1M and 10- 4M solutions of the test drug. Estimates of the pA2 value forthe test drug as an antagonist of phenylephrine or methoxamine were made from the agonist dose-ratios using the method of Arunlakshana & Schild, Br. J. Pharmac. Chemother., 1959,14,48- 58.

The pA2 values for oc, antagonistic activityfor N[(20,11 b(x) - 1,3,4,6,7, 11 b - hexahydro - 2H- benzo[alquinolizin - 2 - yll - N- (2 methanesulphonami- doethyl) methanesulphonamide, N- [(2p,l 1 b(x) 1,3,4,6,7,11 b - hexahydro - 2H- benzo[alquinoizin - 2 yll - N- (2 methanesulphonamidoethyl) - n propanesulphonamide and N- [(2p,l 1 b(x) 1,3,4,6,7,11 b - hexahydro - 2H- benzo[a]quinolizin - 2- V11 - N- (2 methanesulphonamidoethyl) benzenesulphonamide have been found to be respectively 5.32, 5.80 and 6.20 and the (x21oc, selectivity [i.e. antilog of (OC2PA2-OC1 PA2)l forthese compounds are respectively 407,309 and 83. The compounds show great selectivity towards the (X2 receptors.

The invention further provides a compound of formula (1) or a pharmaceutically acceptable acid addition saltfor use in antagonising (x2adrenoceptors in a mammal.

The invention also provides a pharmaceutical composition comprising a compound of general formula (11) or a pharmaceutically acceptable acid addition saitthereof in association with a pharmaceutically acceptable carrier. Any suitable carrier known in the art can be used to prepare the pharmaceutical composition. In such a composition, the carrier is generally a solid or liquid or a mixture of a solid and a liquid.

Solid form compositions include powders, gra- nules, tablets, capsules (e.g. hard and soft gelatine capsules), suppositories and pessaries. A solid carrier can be, for example, one or more substances which may also act as flavouring agents, lubricants. solubilisers, suspending agents,fillers, glidants, compression aides, binders or tablet-disinteg rating agents; itcan also be an encapsulating material. In powdersthe carrier is a finely divided solid which is in admixture with the finely divided active ingredient. In tabletsthe active ingredient is mixed with a carrier having the necessary compression properties in suitable proportions and compacted in the shape and size desired. The powders and tablets preferably contain up to 99%. e.g. from 0.03to 99%, preferably 1 to 80% of the active ingredient. Suitable solid carriers include, for example, calcium phosphate, magnesium stearate, talc, sugars, lactose, dextrin, starch, gelatin, cellulose, methyl cellulose, sodium carboxymethyl cellulose, polyvinylpyrrolidine, low melting waxes and ion exchange resins.

Theterm -composition" is intended to includethe formulation of an active ingredientwith encapsulating material as carrierto give a capsule in whichthe active ingredient (with or without other carriers) is surrounded bythe carrierwhich isthus in associa- tion with it. Similarly cachets are included.

Liquid form compositions include, for example, solutions, suspensions, emulsions, syrups, elixirs and pressurised compositions. The active ingredient, for example, can be dissolved orsuspended in a pharmaceutical ly acceptable liquid carrier such as water, an organicsolvent, a mixture of both or pharmaceutically acceptable oils orfats. The liquid carrier can contain other suitable pharmaceutical additives such as solubilizers, emulsifiers, buffers, preservatives, sweeteners, flavouring agents, suspending agents, thickening agents, colours, viscosity regulators, stabilisers or osmo- regulators. Suitable examples of liquid carriers for oral and parenteral administration include water (particularly containing additives as above e.g. cellulose derivatives, preferably sodium carboxymethyl cellulose solution), alcohols (including monohydric alcohols and polyhydric alcohols e.g. glycerol and glycols) and their derivatives, and oils (e.g. fractionated coconut oil and arachis oil). For parenteral administration the carrier can also be an oily estersuch as ethyl oleate and isopropyl myristate. Sterile liquid carriers are used in sterile liquid form compositions for parenteral administration.

Liquid pharmaceutical compositions which are sterile solutions or suspensions can be utilized by, for example, intramuscular, intraperitoneal or subcutaneous injection. Sterile solutions can also be administered intravenously. When the compound is orally active it can be administered orally either in liquid or solid composition form.

Preferablythe pharmaceutical composition is in unit dosage form, e.g. as tablets or capsules. In such form, the composition is sub-divided in unit dose containing appropriate quantities of the active ingredient; the unit dosage forms can be packaged composition, for example packeted powders, vials, ampoules, prefilled syringes or sachets containing liquids. The unit dosage form can be, for example, a capsule ortablet itself, or it can be the appropriate number of any such compositions in packageform. The quantity of the active ingredient in unit dose of composition may be varied or adjusted from 0.5 mg or less to 750 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 carrierwhere the compounds are in unit dosageform.

The following Examples Illustrate the invention:

EXAMPLE 1 N-[(2p, 1 lbot) - 1,3,4,6,7,1 1b -hexahydro 2Hbenzo[alquinolizin -2-yllethylenediamine Asolution of 2-oxo- 1,3,4,6,7,1 lb(x- hexahydro 2H-benzo[alquinolizine (4g, 0.02 mol) in ethanot (40 CM3) was acidified with ethanolic HCL Ethylenediamine (7.2g,O.12 mol) and 2-oxo- 1,3,4,6,7,1 lbo:hexahydro-2H- benzo[alquinolizine (49,0.02 mol) werethen added to the above solution andthe mixture refluxedforl.5 hour. The solution was then cooled in ice and sodium borohydride (2 g) added 1 GB 2 136 804 A 5 with stirring. The mixture was stirred for 4 hours at ambient temperature and then evaporated. The residue was diluted with water and extracted with chloroform. The extracts were dried and evaporated, the residue was dissolved in ethanol (60cm3) and acidified with ethanolic HCI to precipitate the amine salt (10.5 g), m.p. 225-30'C.

EXAMPLE 2

N-[(2p, 1 lba)- 1,3,4,6,7, 1 1b - Hexahydro -214 benzo[alquinolizin - 2 y/1 - N - (2 - methanesulphona midoethyl) methanesulphonamide Methanesulphonyl chloride (0.72 g, 0.49cm 3) was added over 3 min to a stirred mixture of the amine trihydroch lo ride from Example 1 (1.06g, 3mmol), triethylamine (2.44cm', 17.5mmol), and dichlor omethane (25cM3) After stirring a further 1 hour,TLC showed the reaction was only partially complete. A furtherO.25cM3 of methanesulphonyl chloride was added followed after a further 1 hourbythesame quantity again.The solution wasthen washed with sodium bicarbonate solution, the organic phase was separated, dried, and evaporated. The residue was eluted down an alumina column (70g, Act. 1 Woelm) with chloroform to give 0.63g of pure product. The base was dissolved in ethanol and acidified with ethanolic W followed by addition of etherto precipitate thetitle compound asthe hydrochloride hernihydrate 0.65g, m.p. 152'C.

EXAMPLE 3

N-[(2,6,llba)-1,3,4,6,7,Ilb-hexahydro-2Hbenzo[alquinolizin-2-yll-N'-methylethylene- diarnine A mixture of 4- (3,4dihydroisoquinolinium)bu tane- 2 -one chloride (4.17g), N- methylethylene diamine (2.6 g) and ethanol (15 CM3) was heated at refluxfor 1.5 hour. The solution was then cooled in ice and sodium borohydride (1 g) added. After stirring overnightthe solventwas evaporated, the residue was diluted with water and extracted with chlor oform. The extraetwas dried and evaporated, the residue was dissolved in ethanol and acidified with ethanolic hydrogen chloride to precipitatethe title comound asthe crystalline trihydrochoride 4,4 g, m. p. 245-WC.

EXAMPLE 4

N-[(2p,l lba) - 1,3,4,6,7,1 1b - hexahydro -2H benzo[alquinolizin -2-yll-N- (2-N'-methyl methanesulphonamido) ethyimethanesulphona mide N [(20,11 b(x) - 1,3,4,6,7,11 b - hexahydro - 2H benzo[alquinolizin - 2 yll - W- methylethylene diamine trihyd roch loride (1.84 g) was basified with sodium hydroxide and extracted into CH2C12. The extract was dried and evaporated. The residue obtained above was disolved in CH2C12 (20 CM3) and triethylamine (1.5 9) added, followed by dropwise addition of methanesulphonyl chloride (0.7 mi) to the stirred mixture. After stirring for a further 15 min. the solution was washed with aqueous sodium carbon ate, dried and evaporated. The residue was crystal lised from ethanol (15 mi) to give the title base (1.1 g).

The basewas suspended in ethanol (15 cm') and acidified with aqueous hydrobromic acid (60% w/v) to precipitate the title compound as the hydrobro mide, which was collected and recrystal lised from aqueous ethanol (20% water) to give 1.1 g, m.p. 235-7'C.

EXAMPLE 5 N-(2-[((2P,11ba)- 1,3,4,6,7,llb-Hexahydro-2H- benzo[alquinolizin - 2 - yl)aminolpropanesulphonamide Propanesulphonyl chloride (1.57g, 1.24cM3) was added dropwiseto a vigorously stirred mixture of N[(2p,l 1 b(x) - 1,3,4,6,7,11 b - hexahydro - 2W benzo[a- Iquinolizin - 2 - yllethyl enedia mine trihydrochloride (3.55g), potassium carbonate (6.9g), CH2CH2 (40cm 3) and water (20cM3). After addition was completed the mixture was stirred for 0.5 hour then the organic phase was separated, dried and evaporated. The residue was dissolved in ethanol (30CM3) and acidified with concentrated aqueous hydrobromic acid (60%9 to precipitate the title compound dihydrobromide (2.3g), m.p. 190-92'C.

EXAMPLE 6

N - ((2p, 1 lbcr) - 1,3,4,6,7, 1 1b - Hexahydro - 2H benzo[alquinolizin 2 - yl) - N - (2 (1 - propanesulphonamido)ethyl) - methanesulphonamide Methanesulphonyl chloride (0.75CM3) wasadded dropwiseto a stirred ice cooled mixture of the dihydrobromide from Example 5 (2.579),triethylene (2.75g) and CH2C12 (20cm'). The solution wasthen washed with aqueous sodium carbonate solution, dried and evaporated. The residuewas crystallised from ethanol (15crn') to givethe puretitle base 1.8g. The base was suspended in hot methanol (20CM3) and maleicacid (0.51 g) added. On slowcooling the maleate salt of thetitle compound crystallised and was collected byfiltration and washed with methanol and ethanol to give 2.1g, m.p. 155- 7'C.

EXAMPLE 7

N-(2-[((2,6,llbcr)- 1,3,4,6,7,llb-Hexahydro-2H benzo[alquinolizine-2-yl)aminolethyl)benzenesul- phonamide Benezenesu 1 phony] chloride (2.58crn') was added dropwiseto a stirred icecooled mixtureof N((2p,l 1 boc) - 1,3,4,6,7,11 b) - 1,3,4,6,7,11 b - hexahydro 2H benzo[alquinolizin - 2 - y1)ethylenedia mine tri hydrochloride (7.089), potassium carbonate (1 1.04g), CH2C12 (80CM3) and water (40cm'). AfterO.5 hourthe organic phase was separated, dried and evaporated. The residue was dissolved in methanol (40crn') and acidified with aqueous hydrobromic acid (60% w/v S.G. 1.7) to precipitate thetitle compound as the crystalline dihydrobromide (5.4g). A sample recrys- tallised from aqueous methanol gave m.p. 245-70C.

EXAMPLE 8 N-(2-[N'-((2p,llba)- 1,3,4,6,7,llb-Hexahydro-2H benzo[alquinolizine-2-yl)methanesulphonamidoj ethyl) benzenesulphonamide Methanesulphonyl chloride (0.687g,0.464cm 3) was added dropwiseto a stirred ice cooled mixture of the dihydrochloride productfrom Example 7 (2.23g), triethylamine (1.75g) and CH2C12 (20CM3). After addition was completed stirring was maintained for a further 0.5 hour and the solution then washed with sodium carbonate solution, dried and evaporated. Crystallisation once from ethanol and twice from toluene gave thetitle compound (1.3g), m.p. 146-70C.

EXAMPLE 9

N-[(2pllbot)- 1,3,4,6,7,llb-Hexahydro-9,10- 6 GB 2 136 804 A 6 dimethyoxy2H - benzo[alquinolizin - 2 - yllethylene diarnine 2- Oxo -9,10 dimethoxybenzoquinolizine (7.8g) in ethanol (30CM3) wasjust neutralized by addition of ethanolic-HCI. Ethylenediamine (1 OCM3) wasthen added andthesolution refluxed for 2 hours. The solution wasthen cooled in ice and sodium borohy dride (1.59) added carefullywith stirring.The mixture wasthen allowedto stir at ambienttemperature over night. The solution was evaporated, diluted with water and extracted into chloroform. The extractwas dried and evaporated and the residue dissolved in ethanol (50cm3) and acidified with ethanolic-HCI to precipitate a gum which crystallised when the mix ture was warmed briefly. Aftercooling in icethe title 80 compound was collected as the crystalline trihy drochloride and washed with ethanol to give 7.3g, m.p. 259-620C.

EXMAPLE 10 N-((2,8,llbcr)- 1,3,4,6,7,llb-Hexahydro-9,10dimethoxy-2Hbenzo[alquinolizin-2-yl)-N-(2methanesulphonamidoethyi) methanesulphonamide The trihydroch loride from Example 9 (2.07g) was basified with sodium hydroxide (1 g) in water (1 Oml) and extracted in CH03. The extractwas dried and evaporated. The residue obtained above was dis solved in CH2C12 (20cm 3) and triethylamine (1.5g).

The solution was cooled in ice and methanesu 1 phony] chloride (1.2g, 0.81 CM3) added dropwise with stirring. 95 After addition was complete the mixture was allowed to stand for 15 min then washed with aqueous sodium carbonate, dried and evaporated. The re sidue was purified bytrituration twice with hot ethanol to give the title compound hernihydrate (2.1 g), m. p. 185-7'C.

EXAMPLE 11 N - (2 - [((2p, 1 lbcr) - 1,3,4,6,7, 11 b - Hexahydro - 2H benzo[alquinolizin - 2 - yl) amino 1 ethyl) methanesul- phonamide Methanesulphonic anhydride (1 1.3g) was added portionwise over 2-3 min to a vigorously stirred, ice cooled mixture of N- [(2p,l 1 b(x) - 1,3,4,6,7, 11 b hexahydro - 2W benzo[alquinolizin - 2 - yllethylene- dia mine trihyd roch lo ride (1 7.7g), potassium carbonate (27.6g), CH2C12 (200CM3) and water (1 OOCM3). After stirring for a further 0.5 hou rthe mixtu re was diluted with water, to dissolve MeS03K, the organic phase was separated and the aqueous phase extractedwith chloroform. The combined organic phases were dried and evaporated. The residue was dissolved in ethanol: methanol 0: 1, 300cM3) and acidified with aqueous hydrobromic acid (60% w/v) to precipitate title compound as the dihydrobromide on ice cooling 13.2g, m. p. 238-45'C.

EXAMPLE 12 N-((2p,llbcc)- 1,3,4,6,7,llb-Hexahydro-2Hbenzo[alquinolizine-2yl)-N-(2-methanesulphonamidoethyl) - n - propanesulphonamide The dihydrobromide product of Example 11 was basified by addition of sodium hydroxide (0.4g) in water (1 OCM3 1 and extracted into chloroform. The extractwas dried and evporated. The residuewas dissolved in CH2C12 (15CM3) and triethylamine (0.5g).

The solution was stirred and ice-cooled while prop- 130 192-30C.

anesulphonyl chloride (0.56cm3) was added dropwiseoverl-2 min. Afterstirring for 0.5 hourat ambienttemperatu re the solution was washed with sodium carbonate solution, dried and evaporated.

The residue was chromatographed on alumina (Woelm Act 1, 809) with chloroform as eluant, to give 0.58g of pure title base. The base was dissolved in hot ethanol (6cM3) and acidified with maleic acid (0.165g) to precipitate the title compound asthe maleate on cooling (0.43g),m.p.174-6'C.

EXAMPLE 13

N-((2p,11boc)- 1,3,4,6,7,llb-Hexahydro-2Hbenzo[alquinolizin-2-yl)-N-(2methanesulphonamidoethyl) benzenesulphonamide The dihydrobromide product of Example 11 was basified with sodium hydroxide (0.4g) in water (1 OCM3) and extracted in chloroform. The extractwas dried and evaporated. The residue was dissolved in CH2C1 (1 5cM3) and triethylamine (0.59). The solution was stirred and ice-cooled while benzenesulphonyi chloride (0.64cM3) was added dropwise over 1-2 min. Afterstirring for 0.5 hour at ambient temperature the solution was washed with aqueous sodium carbonate, dried and evaporated, The residue was chroma- tographed on alumina (Woelm Act 1, 80g) using chloroform as eluantto give 1.18g of title base. The base was dissolved in ethanol (1 2cM3) and acidified with maleic acid (0.311 g) to precipitatethe title compound as the maleate, m.p. 197-80C.

EXAMPLE 14 N - [(2p, 1 lba) - 1,3,4,6,7,1 lb - Hexahydro - 2H benzo[alquinolizin - 2 - yll - N - (2 - ethanesulphonamidoethyl) ethanesulphonamide Ethanesulphonyl chloride (2.7g) was added over about5 min. to a stirred ice cooled mixture of N((2p,llb(x)-1,3,4,6,7,llbhexahydro-2H-benzo[alqu inolizin - 2 - y1)ethylenedia mine (10 mmol, prepared from 3.54g of the trihydrochloride),triethylamine (2.5 mO and dichloromethane (25 mi). After addition was complete, the reaction was stirred at ambienttemperature for 1 hour, washed with sodium carbonate solution, dried and evaporated. The residuewas dissolved in ethanol (30mi) and acidified with maleic acid (1. 28g) to precipitate thetitle compound asthe maleate (3g). Recrystallization from methanol gave 2.05g, m.p. 137-138'C.

EXAMPLE 15 N-[(2,6,11ba)- 1,3,4,6,7,llb-Hexahydro-2Hbenzo[alquinolizin - 2 - yll - N - (2 - methanesulphona- mido) ethyI) - ethanesulphonamide Ethanesulphonyl chloride (1.Omi) was added dropwise to a stirred, ice cooled mixture of N- (2 [Q20,1 1 b(x) - 1,3,4,6,7,11 b - hexahydro - 2W benzo[a]quinolizin - 2 -VI)amino 1 ethyl) methanesulphona- mide (5mmol, prepared from 2.439 of the dihydrobromide),triethylamine (1. 25g) and dichloromethane (15 mi). After addition was completethe solution was stirred at ambient temperaturefor 1 hour,washed with sodium carbonate solution, dried and evapo- rated. The residue was chromatographed on neutral alumina to give title base, 1.56 g. The base was dissolved in ethanol (15 ml) and acidified with maleic acid (0.46g) to precipitate the maleate (1 g). Recrystallization from water (about 7 m 1) gave 0.8g, m.p.

Z 7 EXAMPLE 16

N-[(2j5,11ba)- 1,3,4,6,7,llb-Hexahydro-2H benzo[alquinolizin-2-yll-N-(2-chloromethanesul- phonarnidoethyl) chloromethanesulphonamide Chioromethanesul phonyl chloride (3.12g) was added over about 5 min. to a stirred, ice cooled mixtu re of N - ((20,11 boo - 1,3,4,6,7,11 b - hexahydro - 2W benzo[a]quinolizin - 2 y1)ethylenediamine (1 Ommol, prepared from 3.54g atthe trihydrchloride), triethylamine (2.5g) and dichloromethane (25 m]).

After addition was complete, the reaction was stirred forl hour at ambient temperature then washed with sodium carbonate solution, dried and evaporated.

The residue was chromatographed on neutral alumi na using chloroform as eluemtto give 1.8g of title base. The base was dissolved in acetone and acidified with maleic acid (0.5g, 5%xs) to precipitate the maleate 0.55g, m.p. 135-136'C.

EX4/14PLE 17 N-[(2pl lba)- 1,3,4,6,7,llb-Hexahydro-2Hbenzo[alquinolizin - 2 - y/1 - N - (2 - methanesulphona midoethyl) - 4 fluorobenzenesulphonamide 4- Fluorobenzenesulphonyl chloride (1.09) dis solved in dichloromethane (50CM3) was added drop wise over 5 min. to a stirred, ice cooled mixture of N- 90 (2 - [((2p,l 1 b(x) - 1,3,4,6,7,11 b - hexahydro - 2H benzo[alquinoiizin - 2 - yi) amino 1 ethyl) methanesul phonamide, dihydrobromide (2.0g) and triethyla mine (1.9CM3) in dichloromethane (50cm3). The solution was stirred overnight at ambienttempera- 95 ture, washed with aqueous sodium carbonate solu tion followed by brine. The organic phase was dried (M9S04) and concentrated in vacuoto yield a brown syrup which was chromatographed (neutral A1203, CHC13). Two majorfractions were obtained, concen trated in vacuo, and then both converted to the acid maleate by adding a solution of the base in ethanol to a solution of maleic acid (5% excess) in ethanol.

Yields 0.749 m.p. 1824C and 0.60g m.p. 183-5'C.

EXAMPLE 18

N - [(2p, 1 lba) - 1,3,4,6,7,1 1b - Hexahydro - 214 - benzo[alquinolizin 2 - yll - N - (2 - methanesulphona midoethyl) toluene - 4 - sulphonamide p - Tol uen esu 1 pho nyl ch 1 oride (1.0g) dissolved in dichloromethane (50CM3) was added dropwise over 5 min. to a stirred, ice cooled mixture of N- (2 [((2p,l 1 b(x) - 1,3,4,6,7,11 b - hexahydro - 2W benzo[alquinolizin - 2 -y1)aminol ethyl) methanesulphonamide, dihydrobromide (2.0g) and triethylamine (1.9CM3) in dichloromethane (50cm'). The solution Was stirred overnight at ambienttemperature, Washed with aqueous sodium carbonate solution followed by brine. The organic phase was dried (M9S04) and concentrated in vacuoto yield a brown syrup which was chromatographed (neutral A1203, CHC13) and the relevant fractions combinedand concentrated in vacuo. The residue was dissolved in ethanol and warmed gentlywhereupon the title product crystallised. The productwas collected by filtration, washed with ethanol and dried in vacuo. Yield 0.709, m.p. 150- 4C.

EXAMPLE 19 N-[(2p,11bot)- 1,3,4,6,7,Ilb-Hexahydro-2Hbenzo[alquinolizin-2yij-N-(2-methanesulphona- midoethyl)-4-methoxybenzenesulphonamide GB 2 136 804 A 7 4- Methoxybenzenesulphonyl chloride (1.19) dissolved in dichloromethane (50CM3) was added dropwise over 5 min. to a stirred, ice cooled mixture of N(2 - [((2p,l 1 b(x) - 1,3,4,6,7,11 b - hexahydro - 2W benzo[alquinolizin - 2 - yi) amino 1 ethyl) methanesulphonamide, dihydrobromide (2.09) and triethylamine (1.9CM3) in dichloromethane (50cM3) The solution was stirred overnight at ambienttemperature, washed with aqueous sodium carbonate solu- tion followed by brine. The organic phase was dried (M9S04) and concentrated in vacuoto yield a yellow syrup which was chromatographed (neutral A1203, CH03) and the relevant fractions combined and concentrated in vacuo. The residue was dissolved in ethanol and warmed gentlywhereupon thetitle base crystallised. The productwas collected byfiltration, washed with ethanol and dried in vacuo. Yield 1.41 g, m.p. 148-52'C.

EXAMPLE 20 N - [(2p, 1 lba) - 1,3,4,6,7,1 1b - Hexahydro - 214 benzo[alquinolizin - 2 - yll- N - (2 - methanesulphonamidoethyl) - 4 nitrobenzenesulphonamide 4 - Nitrobenzenesu lphonyl chloride (19) was added portionwise over 2-3 min. to a stirred, ice cool mixture of N - (2 [((2p,l 1 b(x) - 1,3,4,6, 7,11 b - hexahydro - 2W benzo[a]quinolizin - 2 yl) amino 1 ethyl) methanesulphonamide (4mmol, prepared from 1.94g of the dihydrobromide), triethylamine (0.5g) and dichloromethane (1 5mi). After addition was complete, the solution was stirred at ambient temperature for 1 hour, washed with sodium carbonate solution, dried and evaporated. The residue was chromatographed, on neutral alumina to give 0.7g of title compound. recrystallisation from ethyl acetate gave 0.4g, m.p.

177-178'C.

EXAMPLE 21 N - [2p, 11 bcr) - 1,3,4,6,7, 11 b - Hexah ydro - 2H benzo[alquinolizin - 2 - yllpropane - 1,3 - diamine A m ixtu re of 3,4 dihyd ro - 2 - (3 - oxobutyi)iso- quinolinium chloride (38.4 g) and 1,3-propanediami ne (67 cm3) was refl uxed for 11/2 hou rs in ethanol (100 CM3). Th e reaction was then cooled in ice and sodium borohydride (8 g) added portionwise with stirring. Stirring was continued overnight at room temperaturethen the mixture concentrated in vacuo. The residuewas carefully hydrolysed with water and then extracted with dichloromethane. The combined organic phases were washed (brine), dried (Na2S04), and evaporated to dryness. The residue was dissolved in ethanol and acidified with ethanolic hydrogen chlorideto precipitate the trihydrochloride (44.5 g).

The salt was converted to the free base a nd used i n the p repa ration of N - (3 - [Q2 P, 11 b(x) - 1,3,4,6,7,11 b - hexa hydro - 2H - benzo[al - q u inol izi n - 2 - yi) a mi no] propyl) methanesulphonamide.

EXAMPLE 22 N- (3-[((2p, 1 lba) - 1,3,4,6,7,1 lb-Hexahydro 2Hbenzo[alquinolizin -2- yl) amino] propyl) methanesulphonamide Asolutionof methanesulphonic anhydride (9.0 g) in dichloromethane (100 CM3) was added dropwise over 2-3 mins. to a rapidly stirred, ice-cooled mixture of N- [(2p,l 1 b(x) - 1,3,4,6,7,11 b - hexahydro - 214benzo[alquinolizin-2-yilpropane-1,3-diamine(10.5 8 g), potassium carbonate (16.5 g), dichforomethane (100 cm') and water (100 cm3). The reaction was stirred for a further 0.5 hr. then the organic phase was separated, washed (brine), dried (Na2S04), and con centrated in vacuoto leave a viscous dark brown syrup (13.6 g).

The residue was dissolved in ethanol (125 CM3) and 60 a solution of oxalic acid dihydrate (10.6 g) in ethanol (75 CM3) was added. The solution was allowed to crystallise overnightthen the white crystalline salt collected byfiltration, washed well with ethanol and dried in vacuoto yield the dioxalate (16.6 g) which could be recrystallised from methanollwater (1: 1).

The saltwas converted to thefree base and used in the preparation of N[(2p,l 1 b(x) - 1,3,4,6,7,11 b - hexahydro - 2H- benzo[alquinolizin - 2 yll - N- (3 - methanesulphonamidopropyi) methanesulphona mide.

EXAMPLE 23

N-((2,6,11ba)- 1,3,4,6,7,llb-Hexahydro-2H benzo[alquinolizin -2-yi)(3-methanesulphonamido - n - propyl)methanesulphonamide Asolution of methanesulphonyl chloride (0.71 g) in dichloromethane (20 cm3) was added dropwiseto an ice-cooled stirring solution of the product of Example 22 (2.0 g) and triethylamine (0.9 CM3, 0.65 g) in dichloromethane (20 CM3). The reaction was allowed to stir overnight at room temperaturethen washed with aqueous sodium carbonate solution. The orga nic phase was dried (M9S04) and concentrated in vacuoto yield a pale brown syrup. This was dissolved in isopropanol and acidified with ethanolic hydrogen 85 chlorideto yield the pure product hydrochloride as a white solid. The material was collected byfiltration washed with a little cold IPA and dried in vacuo at about 800C. Yield 0.74 g.

Claims

1. A benzoquinolizine of the general formula R1 N) 2, N R302 S/ A-NR.SO 2 or a pharmaceutically acceptable acid addition salt thereof wherein R represents hydrogen or lower alkyl, R' and R 2 which may be the same or different each represent hydrogen, lower alky], lower alkoxy or halogen, R'and R4which maythe same or different each represents lower alky], halo(lower)alkyl or aryl and A represents a lower alkylene group having 1 to 3 carbon atoms in the chain between the two N atoms.

2. A compound as claimed in Claim 1 wherein A is ethylene.

3. A compound as claimed in Claim 1 or 2 wherein R'andR 4 each represent lower alkyl or aryl.

4. N-[(20,llb(x)-1,3,4,6,7,llb-Hexahydro-2Hbenzo[alquinolizin-2-yil-N-(2methanesulphonamidoethyl) methanesulphonamide or a phar- GB 2 136 804 A 8 maceutically acceptable saitthereof. 55

5. N-((20,llb(x)-1,3,4,6,7,llbHexahydro-2Hbenzo[alquinolizine-2-yi)-N-(2-methanesulphonamidoethyi)-npropanesulphonamideorapharmaceutically acceptable salt thereof.

6. N-((2p, llb(x)-1,3,4,6,7,llb-Hexahydro-2Hbenzo[alquinolizin-2-yi)-N-(2methanesulphonamidoethyi)benzenesulphonamideorapharmaceutically acceptable saitthereof.

7. N-[(2p,llbot)-1,3,4,6,7,llb-Hexahydro2Hbenzo[alquinolizin-2-yll-N- (2-N'- methyl- methanesulphonamido) ethyl methanesulphonamide, N- Q2p,l 1 boo - 1,3,4,6, 7,11 b - hexahydro -2Hbenzo[alquinolizin-2-yl)-N-(2-(1-propanesulphonamido) ethyl) methanesulphonamide, N- (2- [N'- Q2p,l 1 b(x) 1,3,4,6,7,11 b - hexahydro 2H- benzo[alquinolizin - 2 yi) methanesulphonamido 1 ethyl) benzenesulphonamide, N- ((2p,l 1 b(x) - 1,3,4,6,7,1 1b - hexahydro 9,10dimethoxy - 2W benzo[alquinolizin - 2- y1) - N- (2 methanesulphonamidoethyl) methanesulphonamide, N- [(20,1 lb(x) 1,3,4,6,7,1 lb- hexahydro -2H- benzo[alquinolizin -2-yll - N(2-chloromethanesulphonamidoethyl) chloromethanesulphonamide or N - Q20,1 1 b(x) - 1,3,4,6,7,11 b - hexahydro - 2W benzo[alquinolizin - 2 - yi) (3 methanesulphonamido - n - propyl) methanesulphonamide or a pharmaceutical ly acceptable acid addition saitthereof.

8. A process for preparing a compound claimed in Claim 1 which comprises (a) reacting a reactive derivative of a sulphonic acid of formula R 5S0,0H [wherein R' is lower alkyl, halo(lower)alkyl or aryll with a benzoquinolizine of the general formula (111) 1 C 1 N R 2 Oll) H.A.NHR (wherein R, R', R 2 and A are as defined in Claim 1) or with a benzoquinolizine of the general formula (IX) P1 2 N (1x) R 0 1) A HN.ANRSO 2 R (whereinAR,Rl,R 2 and R 4 areas defined in Claim 1) orwith a benoquinolizine of the generalformula (X) A -7 9 GB 2 136 804 A 9 RI R 2 (X) 3 R SO A NH2 (wherein A, W, R 2 and R 3 are as defined in Claim 1) or (b) reacting a benzoquinolizine of general formula (xl) RI N R 2 xl) R 3SO 2 NH (wherein W, R2 and R3 a re as defined in Claim 1) with a compound of formula X-A-N13SO2R 4 (X11) (wherei n A a nd R' are as defi ned i n Cla im 1 a nd X is halogen) and, if desired, alkylating a compound of formula (1) in which R is hydrogen to give a compound in which R is lower alkyl, reducing a compound in which R 3 andlor R 4 is nitro substituted phenyl to give a compound in which R 3 and /or R' is amino substituted phenyl, acylating a compound in which R 3 andlor R % amino substituted phenyl to give a compound in which R 3 andlor R 4 is acylamino substituted phenyl, separating a mixture of isomers of formula (1) or converting a free base of formula (1) a pharmaceutically acceptable saitthereof.

9. A process as claimed in Claim 8 wherein the reactive derivative of the sulphonic acid of formula (11) is an acid halide or anhydride.

10. A process for preparing a benzoquinolizine substantially as hereinbefore described with reference to Example 2 or4.

11. A process for preparing a benzoquinolizine substantially as hereinbefore described with reference to any one of Examples 6,8,10,

12 and 13 12. A process for preparing a benzoquinolizine substantially as hereinbefore described with reference to any one of Examples 14,15,16,17, 18,19,20 and 23.

13. A benzoqu inolizine whenever prepared by the process claimed in anyone of Claims 8 to 12.

14. A pharmaceutical composition comprising a compound claimed in any one of Claims 1 to 7 and 13 in association with a pharmaceutically acceptable carrier.

15. A compound of general formula N R (XIV) N \ - 2 4_ A NK wherein R, W, R 2 and A are as defined in Claim 1 and Z1 and Z2 are both hydrogen orZ' is hydrogen and Z2 is S02R 4 (where R 4 is as defined in Claim 1) orZ' is S02 R 3 (where R 3 is as defined in Claim 1) and Z2 is hydrogen.

16. A process for preparing a compound claimed in Claim 15 which comprises (a) reductively aminating a compound of formula OV) RI C1 N 1 R 21 C (VI) 0 (where R' and R 2 areas defined in Claim 1) with a diamine of formula (V11) NH2ANHR (V11) (whereAand Rare as defined in Claim 1) and a reducing agent or (b) reductivelyaminating a quaternary salt having the formula (V111) RI A- + N-CH 2 CH 2 COCH 3 00- R e_ (VITO (where R' and R 2 are as defined in Claim 1 and A- is an anion) with a diamine of formula (V11) (as defined above) and a reducing agent (c) selectively sul phonating a benzoquinolizine of formula (111) Ri 1 N R 2 (111) H.A.NHR GB 2 136 804 A 10 (wherein R, W, R 2 andAare as defined in Claim 1) with a reactive derivative of a sulphonic acid of formula (11) R5S020H (11) (where R5 is as defined in Claim 8) or (d) reductively aminating a benzoquinolizine of general formula (V]) [as defined above] with an amine offormula NH2ANRSO2R4 (whereA,Rand R4 areas defined in Claim 1) and a reducing agent 15 or (e) reacting a benzoquinolizine of general formula (Xl) R1 N 2 0 xl) R 3SO 2 NH (where W, R 2 and R' are as defined in Claim 1) with a phthalimido protected haloamine of formula OV) 0 Y-A-N 0 0 (IV) (whereA is as defined in Claim 1 and Y is halogen) in presence of a strong base and removing the phthalimido protecting group.

17. A compound as claimed in Claim 15 substantial ly as herein before described with reference to any 25 one of Examples 1, 3,5,7,9,11,21 and 22.

Printed in the United Kingdom for Her Majesty's Stationery Office, 8818935, 9184, 18996. Published at the Patent Office, 25 Southampton Buildings, London WC2A lAY, from which copies may be obtained.

i A I -tl i