BACKGROUND OF THE INVENTION

WO 96/40156 and WO 96/40190, each published 19 December 1996, disclose therapeutic derivatives of diphosphonates. These compounds have the formula A-V'and are obtained by reacting a diphosphonic acid compound with a pharmaceutically active entity. In these compounds of formula A-V, A is the residue of a pharmaceutically active entity and V is the residue of the diphosphonic acid compound.

OBJECTS OF THE INVENTION

It is an object of the present invention to provide novel pharmaceutically active compounds having improved utility for treating various diseases, especially diseases of the bones and teeth. Further objects are to provide new pharmaceutically active chemical entities for treating infectious diseases of bone and teeth, osteomyelitis, periodoπtal disease, urinary catheter-related infections, infectious urinary calculi, gastritis and peptic ulcers, and bone cancer. Another object is to provide intermediates for preparing these new chemical entities. Still another object is to provide methods for treating these diseases, and methods for preparing the pharmaceutically active agents. These and other objects of the present invention will be apparent form the following description.

SUMMARY OF THE INVENTION

Novel therapeutic agents having utility in achieving the foregoing objects of the invention are obtained with compounds prepared by reacting a 2,2-bis-(disubstituted- phosphoryl)-ethylsulfanyl-acetic acid compound with a pharmaceutically active chemical entity effective to treat the underlying disease.

DETAILED DESCRIPTION

The pharmaceutically active therapeutic agents of the present invention are compounds obtained by reacting a 2,2-bis-(disubstituted-phosphoryl)-ethylsulfanyl-acetic acid compound

with a pharmaceutically active chemical entity effective to treat the underlying disease, i.e., an infectious disease of bone or teeth, osteomyelitis, periodontal disease, urinary catheter-related infections, infectious urinary calculi, gastritis and peptic ulcers, and bone cancer. The diphosphonate moiety causes the therapeutic agent to be attracted to, and to concentrate on, the surfaces of various salt crystals and the more complex forms of such crystals, such as hydroxyapatite, a major constituent of bone and the surface of dentition. Bacteria associated with these crystals are thereby exposed to an elevated concentration of the therapeutic agent, relative to the surrounding milieu. The therapeutic moiety is derived from a pharmaceutical that is pre-selected because of its recognized ability to treat the underlying disease state. The diphosphonate intermediates of the present invention can be prepared by reacting thioglycolic acid with a tetraester of ethylidenediphosphonic acid, H ₂ C=C(PO3R ) ₂ , wherein the group R is an alkyl group of 1-10 carbons. The reaction product is the corresponding

2,2-bis-(di-substituted-phosphoryl)-ethylsulfanyl-acetic acid compound. The latter compound is then reacted with a pharmaceutically active compound of the formula A-NH2 or

A-COOCH2CI wherein A is the residue of the pharmaceutically active compound. (If neither of the -NH2 or -COOCH2CI groups are present in the pharmaceutically active compound, they are introduced by using conventional chemical techniques known to those skilled in organic and medicinal chemistry fields.) In the former case the resulting compound has the following formula

while in the latter case the chloro compound is replaced by the group

whereby the resulting compound has the formula

The above-illustrated compound is susceptible to in vivo cleavage by the enzyme esterase whereby the starting pharmaceutically active compound is reconstituted.

The reaction between the pharmaceutically active compound and the 2,2-bis-(di-substituted-phosphoryl)-ethylsulfanyl-acetic acid compound takes place under well-known conventional and standard conditions for reactions of this type. An illustration of these reaction conditions is shown in Example 2. Additional illustrations are shown in the two published disclosures mentioned above, WO 96/40156 and WO 96/40190.

The 2,2-bis-(di-substituted-phosphoryl)-ethylsulfanyl-acetic acid compounds of the present invention are prepared by reacting thioglycolic acid with a tetra-substituted ethylidene diphosphonate compound wherein the alkyl group has from 1 to 10 carbon atoms. The reaction preferably takes place in a polar solvent, such as a halogenated hydrocarbon , e.g., dichloromethane for a period of from about 1 or 2 hours to about 20 hours at a temperature of from about 10° C to about 30° C. Compounds wherein R is H are obtained by reacting any of the foregoing compounds wherein R is alkyl with bromotrimethyl silane, then with water. The reaction is preferably carried out in a polar solvent, preferably dry, such as a halogenated hydrocarbon, a specific example of which is dichloromethane, at about room temperature followed by addition of water.

Compounds of the present invention have been shown to bind in a saturable way to a slurry of rat tibia and to show activity against microorganisms. Other tests have shown that the binding increases with time and that the bound compound can be removed from the bone slurry by exposure to CaCl . Taken together these tests demonstrate that the compounds of the present invention bind to and are retained by calcium sites in bone and, further, inactivate bacteria.

The compounds of the present invention are intended for treatment of a member of a mammalian species, e.g., dogs, mice, primates and humans, and normally are administered orally but also can be administered by other routes, for example, parenterally or by injection. In general, these compounds can be used at a dosage amount that is in the range of from about 10% to about 1000%, preferably from about 25% to about 750%, and most preferably from about 50% to about 500% that at which the pharmaceutically active component itself is used. The compounds of the present invention are used in the form of various pharmaceutical preparations such as tablets, capsules, granules, syrups and the like which are well known in the art, and which can be prepared by methods known per se using suitable diluents, bindings, disintegrators, coating agents and the like. Other preparations suitable for injection or parenteral use also can be prepared by techniques known in the art.

Other non-pharmaceutical compounds are obtained in similar manner by replacing the pharmaceutically active compound with an insecticide, fungicide, poison for vermin, and the like.

Examples of useful pharmaceutically active chemical entities suitable for reaction with the 2,2-bis-(di-substituted-phosphoryl)-ethylsulfamyl-acetic acid compounds of the present invention include, without intending to be limited thereby:

an aminoglycoside such as amikacin (US patent 3,781,268), apramycin (US patent 3,691,279), arbekacin (US patent 4,107,424) , bambermycin (US patent 3,674,866), butirosin (US patent 3,541,078), dibekacin (German patent 2,135,191), dihydrostreptomycin (US patent 2,498,574), fortimycin A (US patent 3,976,768) and fortimycin B (Japan Kokai 75 145,588), gentamicin (US patents 3,091,572 and 3,136,704), isepamicin (Belgian patent 818,431), kanamycin (US patent 2,931,798), micronomicin (German patent 2,326,781), neomycin (2,799,620), neomycin undecylenate (US patent 3,022,286), netilmicin (German patent 2,437,160), paromomycin (US patent 2,916,485), ribostamycin (German patent 1,814,735), sisomicin (US patent 3,832,286), spectinomycin (US patent 3,234,092), streptomycin (US patent 2,868,779), streptonicozid (Pennington et al . , J. Am. Chem. Soc. 75, 2261 (1953) and tobramycin (Stark et al., Higgens, Kastner; Thompson, Presti; Wick, Welles, Anti icrob. Ag. Chemother. , 1967, 314-348; an amphenicol such as azidamfenicol (US patent 2,882,275), chlorampphenicol [Bartz, J. Biol . Chem. 172, 445 (1948)], chloramphenicol palmitate (US patent 2,662,906), chloramphenicol pantothenate (US patent 3,078,300), florfenicol (US patent 4,235,892) and thiamphenicol [Cutler et al. , J. Am. Chem. Soc. 74, 5475 (1952)]; an ansamycin such as rifamide (US patent 3,313,804) ; a carbapenem, for example, imipenem (US patent 4,194,047); a cephalosporin, for example, cefaclor (US patent 3,925,372), cephadroxil US 3,816,253) , cefamandole US patent 3,641,021), cefatrizine (US patent 3,970,651), cefazedone (German patent 2,345,402), cefazolin (US patent 3,516,997), cefixime (US patent 4,409,214), cefmenoxime (US patent 4,098,888), cefodizime (US patent 4,278,793), cefonicid (US patent 4,093,723), cefoperazone (US patent 4,410,5220, ceforanide (US patent 4,172,196), cefotaxime (US patent 4,098,888), cefotiam (German patent 2,607,064), cefpimizole (US patent 4,217,450), cefpiramide (Belgian patent 833,063), cefpodoxime proxetil (US patent 4,486,425), cefroxidine (US 4, 073, 902) , cefsulidin, (US 4,065,619), ceftazidime (US patent 4,258,041), cefteram (Belgian patent 890,499), ceftozole (US patent 3,516,997), ceftibuten (US 4,634,697), ceftizoxime (US patent 4,427,674), ceftriaxone (US

patent 4,327,210), cefuroxime (US patent 3,974,153), cefuzonam (US patent 4,399,132), cephalexin (US patent 3,275,626), cephaloglycin (US patent 3,422,103), cephaloridine (French patent 1,384,197), cephalosporin C (US patent 3,082,155), cephalothin (French patent 1,384,197), cephapirin sodium (US patent 3,422,100), cephradine (US patent 3,485,819) and pivecfalexin (German patent 1,951,012) ; a cephamycin such as cefbuperazone (US patent 4,263,292), cefmetazole (US patent 4,007,177), cefminox (US patent 4,357,331), cefotetan (US patent 4,263,432) and cefoxitin (US patent 4,297,488); a monobactam such as aztreonam (Netherlands patent application 8,100,571, carumonam (US patent 4,572,801), and tigemonam (US patent 4,638,061) ; an oxacephem such as flomoxef (US patent 4,532,233) and moxalactam (US patent 4,138,486); a penicillin such as amdinocillin (US patent 3,957,764, amoxicillin (US patent 3,192,198) ampicillin (US patent 2,985,648), carbenicillin (US patent 3,142,673), clometocillin (US patent 3,007,920), cloxacillin (Doyle et al., J. Chem. Soc. 1963, 5838), cyclacillin (US patent 3,194,802), dicloxacillin (US patent 3,239,507), epicillin (US patent 3,485,819), floxacillin (US 3,239,507) , hetacillin (US patent 3,198,804), lenampicillin (US patent 4,342,693), metampicillin (Belgian patent 661,232) , oxacillin (US patent 2,996,501), penicillin V (Brandl et al., Wien. Med. Wochenschr. 1953, 602), piperacillin (US patent 4,087,424), pivampicillin ((US 3,660,575), propicillin (British patent 877,120), sulbenicillin (US patent 3,660,379) and ticarcillin (US patent 3,282,926); a lincosamide such as clindamycin (US patent 3,475,407) and lincomycin (US patents 3,086,912 and 3,155,580) ; a macrolide such as azithromycin (US patent 4,517,359), carbomycin (US patent 2,960,438), clarithromycin (US patent 4,331.803), erythromycin (US patent 2,823,203), josamycin (Japanese patent 66 21,759), leucomycins (US patent 3,535,309), midecamycins (US patent 3,761,588), miokamycin (Japanese Kokai 74 124087) , oleandomycin (US patents 2,757,123 and 2,842,481) , primycin (US patent 3,498,884), rokitamycin (German patent 2,918,954), rosaramicin (S. African patent 71 00,402), roxithromycin (US patent 4,359,545), spiramycin (US patent 2,943,023), and troleandomycin (British

patent 877,730) ; a polypeptide such as bacitracin (US 2,915,432), capreomycin (US patent 3,143,468), colistin (Japanese patent 57 4898) , enduracidin (British patent 1,163,270), envio ycin (US patent 3,892,732), gramicidin (US patent 2,534,541), mikamycin (French patent 1,349,946), polymyxin (US patent 2,565,057), polymyxin B-methanesulfonic acid (US patent 3,044,934), pristinamycin (US patent 3,154,475), ristocetin (US patent 2,990,329), Teicoplanin (US patent 4,239,751), thiostrepton (US patents 2,982,689 and 2,982,698), tuberactinomycin (US patent 3,639,580), tyrocidine (US patent 3,265,572), tyrothricin, vancomycin (US patent 3,067,099), viomycin (US patent 2,633,445), virginiamycin, and zinc bacitracin (US patent 2,803,584) ; a tetracycline such as apicycline (Netherlands patent application 6,515,688), chlortetracycline (US patent 2,482,055), clo ocycline (Belgian patent 628,142), demeclocycline (US patent 2,878,289), doxycycline (US patent 3,200,149), guamecycline (British patent 1,042,207) , lymecycline (US patent 3,043,716), meclocycline 2,984,686), methacycline (US patent 3,026,354), minocycline (US patents 3,148,212 and 3,226,436), oxytetracycline (US patent 2,516,080), penimepicycline (British patent 897,826), pipacycline (British patent 888,968), rolitetetracycline (US patent 3,104,240), sancycline (US patent 3,019,260), senociclin (US patent 3,218,335), and tetracycline (US patent 2,699,054); cycloserine (US patent 2,773,878), doxorubicin (US patent 3,590,028), and mupirocin (US patent 3,977,943) ; a 2,4-diaminopyrimidine such as brodimopri (US patent 4,024,145), tetroxoprim (US patent 3,992,379), and trimethoprim (US patent 3,049,544) ; a nitrofuran such as furazolium chloride (US patent 3,169,970), nifuradene (US patent 2,746,960), nifurprazine (British patent 966,832), nifurtoinol (US patent 3,446,802), and nitrofurantoin (US patent 2,610,181); a cjuinolone or quinolone analogs such as amifloxacin (US patent 4,499,091), cinoxacin (US patent 3,669,965), ciprofloxacin (US patent 4,670,444), difloxacin (US patent 4,730,000), enoxacin (US patent 4,359,578), fleroxacin (US patent 4,398,029), flumequine (US patent 3,896,131), lomefloxacin (US patent 4,528,287), miloxacin (US patent

3,799,930), nalidixic acid (US patent 3,149,104), norfloxacin (US patent 4,146,719), ofloxacin (US patent 4,382,892), oxolinic acid (US patent 3,287,458), pefloxacin (US patent 4,292,317), pipemidic acid (US patent 3,887,557), piromidic acid (British patent 1,129,358), rosoxacin (US patent 3,753,993), sparfloxacin (Antimicrobial Aσents & Chemotherapy 1989, 3_3, 1167-1173) and tosufloxacin (US patent 4,704,459); a sulfonamide such as acetyl sulfamethoxypyrazine (US patent 3,098,069), acetyl sulfisoxazole (US patent 2,721,200), azosulfamide (US patents 2,123,634 and 2,148,910), benzylsulfamide, chloramine-B, chloramine-T, dichloramine T (US patent 2,495,489), formosulfathizale [Druey et al., Helv. Chim. Acta 31, 2184 (1948)], N -formylsulfisomidine (German patents 1,122,511 and 1,126,857), N ⁴ -β-D-glucosyl- sulfanilamide [Kuhn et al., Ber. 71, 621 (1938)], mafenide (US patent 2,288,531), 4'- methylsulfamoyl) -sulfanilanilide (French patent 817,034), p-nitrosulfathiazole (US patent 2,443,742), norprylsulfamide (US patent 2,262,544), phthalylsulfacetamide [(Basu, J. Indian Chem. Soc. 26, 130 (1949)], phthalylsulfa- thiazole (US patents 2,324,013 and 2,324,015), salazosulfadimidine [Korkuczanski, Przem. Chem. 37, 162 (1958)], succinylsulfathiazole (US patents 2,324,013 and 2,324,014), sulfabenzamide (US patent 2,240,496), sulfacetamide (US patent 2,411,495, sulfachlorpyridazine (US patent 2,790,798), sulfachrysoidine [Gley et al., Coinpt. Rend. Soc . Biol . 125, 1027

(1937)], sulfacytine (US patent 3,375,247) , sulfadiazine (US patent 2,407,966), sulfadicramide (US patent 2,417,005), sulfadimethoxine (US patent 2,703,800), sulfadoxine (US patent 3,132,139), sulfaethidole [Wojahn et al . , Arch . Phar . , 284, 53

(1951)3, sulfaguanidine (US patents 2,218,490, 2,229,784 and 2,233,569) , sulfaguanole (US patent 3,562,258), sulfalene (US patent 3,098,069), sulfaloxic acid (German patent 960,190), sulfamerazine (US patent 2,407,966), sulfameter (US patent 3,214,335), sulfamethazine (US patent 2,407,966), sulfamethizole

(US patent 2,447,702), sulfamethomidine (German patent 926,131), sulfamethoxazole (US patent 2,888,455), sulfamethoxypyridazine

(US patent 2,712,012), sulfametrole (US patent 3,247,193), and sulfamidochrysoidine (US patent 2,085,037); a sulfone such as acedapsone [Fromm et al. , Ber, 41, 2270 (1908)] , acediasulfone [Jackson, J. Am. Chem. Soc. 70, 680

(1948)] , acetosulfone sodium (US patent 2,358,365), dapsone (French patent 829,926), diathymosulfone (British patent 758,744), glucosulfone sodium (Swiss patent 234,108), solasulfone (British patent 491,265), succisulfone (US patent 2,268,754), sulfonilic acid, p-sulfanilyl-benzylamine (Dewing, J. Chem. Soc . 1946, 466), p,p' -sulfonyl-dianiline-iV,-V' - digalactoside, sulfoxone sodium (US patent 2,256,575), and thiazolsulfone (2,389,126); others such as clofoctol (US patent 3,830,852), hexedine (US patent 3,357,886), nitroxoline [Kostanecki, Ber. 24, 154 1891)] , xibornol (British patent 1,206,774) ; hydnocarpic acid [Diaper et al. , Bioche J. 42, 581 (1948)3, p-aminosalicylic acid (US patent 427,564), p-aminosalicylic acid hydrazide (Spanish patent 206,645) , benzoylpas (British patent 676,363), 5-bromosalicylhydroxamic acid (Urbanski et al. , .Nature 170, 753 (1952) , capreomycin (US patent 3,143,468), clofazimine (Barry et al., iVature 179, 1013 (1957) , cyacetacide (US patent 2,849,369), dihydrostreptomycm (US patent 2,498,574), envio ycin (US patent 3,892,732), ethambutol [Wilkinson et al., J. Am. Chem. Soc. 83, 2212 (1961)] , ethionamide (British patent 800,250), 4'- formylsuccinanilic acid (German patent 852,086), furonazide [Miyatake et al . J. Pharm . Soc. Japan 75, 1066, (1955)], glyconiazide (US patent 2,940,899), isobutol (US patent 3,718,655) , isonizid (US patent 2,830,994), isoniazid methanesulfonate (US patent 2,759,944), morphazinzmide (German patent 1,129,492), opiniazide [Pershin et al., CA. 51, 10747e (1957)], pasiniazide (Swiss patent 303,085), phenyl aminosalicylate (US patent 2,604,488), protionamide (British patent 800,250) , pyrazinamide (German patent 632,257) , rifampin (US patent 3,342,810) , salinizid [Hart et al. , Aπtibot. & Chemother. 4, 803 (1954)] , subathizone [Bernstein et al . , J. Am. Chem. Soc. 73, 906 (1951), sulfoniazide (US patent 2,727,041), thiacetazone [Domagk et al., Naturwiss 33, 315 (1946)] , tiocarlide (US patent 2,703,815), tuberactinomycin (US patent 3,639,580), tubercidin [Anzai et al., J. Antiobiot . 10A, 201 (1957)], tuberin (Japanese patent 64 7399), verazide [Fox et al . , J. Org. Chem. 18, 983 (1953), viomycin (US patent 2,633,445) , and viomycin pantothenate (German patents 954,874 and 1,011,800) .

The following examples illustrate the present invention without, however, limiting the same thereto.

EXAMPLE 1

A . 2 , 2-Bis-(diethoxyphosphorv 1 )-ethylsulfanyl-acetic acid

Tetraethyl ethyl idenephosphonate (3.6 g, 12 mmol) was dissolved in dry dichloroirε thane (30 ml), thioglycolic acid (1.1 g, 12 mmol) was added and the mixture was allowed to react overnight. It was evaporated and the residue was purified using column chromatography using a d ichloromethane-met hano 1 9:1 mixture as eluant to give 4.5 g (95.7%) of the title compound as a syrup. MS m\e 392 (M) . Η-NMR: δ 4.20 (8H, q, OCH,); (2H, s, SCH _j COOH ⁾ ; 3.20 (2H, m, CH ₂ ); 2.S (IH, , -CH- ) ; 1.35 ⁽ 12H, t, -CH, ) .

B. "-( 4-( ( 2 , 2-Bis-(dietho yphosphoryl ) -ethyl su 1 f any 1 )- acetoxy ethoxycarbonyl )-piρerazin-l-yl )-l-ethyl-6- fluoro-4-oxo-l , 4-di hydroquino 1 ine-3-carboxy 1 ic acid

A solution of l-ethyl-6-f luoro-1 , 4-dihydro-4-oxo-7- [4 '- [ ( l"-chloroetho y ) carbonyl ] -1 ' -piperaz inyl ]quino line-3- carboxylic acid (J. Med. Chem. 34, 78 (1991) (0.8 g, 1.9 mmol), 2, 2-bis-(diethoxyphosphory 1 ) -ethyl sul f any 1-acet ic acid (1 g, 5 mmol) and t r iethy lamine (0.37 ml, 2.6 mmol) in dry dimethyl- formamide (14 ml) was stirred at 90°C for 2 hours. After evaporation of the solvent the residue was extracted with dichlorome hane. The solvent was distilled off and the residue was purified by column chromatography using dichloromethane-met hano 1 98:2, then 97:3 and 95:5 mixtures as eluants to yield 0.15 g (10%) of the title compound. M.p. : 89-90'C. MS (FAB)m/e 768 (M+l). Η-NMR δ (CDC1,) 15.0 (IH, s, -COOH); 8.68 (IH, s, H-2); 8.05 (IH, d, H-5) 6.9 (fH, d, H-8; 5.85 (2H, s, 2"-CH, ); 4.2 (4H, m, OCH _j ) ; 3.8 (4H, m, 3'-CH,+ 5'-CH, ) ; 3.4 (2H, s, 4"-CH, ); 3.1-3.3 (6H, m, 2'-CH ₁ -r6 ^, -CH ₁ + 5'-CH,) ; 2.1 (IH, m, 6"-CH);1.6 (3H, t, NCH,CH, ) ; 1.4 (12H, ^" t, OEt ^" ). ^ir C-NMR (CDCl,) δ 177.2; 169.6; 167.3; 155 ^* .2 153.5- 152.4; 147.5; 146.1; 146.0; 121.4; 113.3; 113.0; 106.7; 104.7 81.3; 66.8:63.4; 63.3; 63.2; 63.1; 50.0; 44.2; 43.0; 40.5; 39.0 37.6; 34.9; 29.1 ; 27.3; 16.6; 14.8. Anal. Calcd. for C _1rj H ₁₄ FN,0.,P,S (767.69):

C, 46.94 ^" ; H, 5.78; N, 5.47; P, 8.08. Found: C, 46.68; H, 5.89; N, 6.0; P, 8.22.

EXAMPLE 2

6-[2-{2-[2,2-Bis-(diethoxy-phosphoryl)-ethylsulfanyl]-ace tylamino}- 2-(4-hydroxy-phenyl-acetamindo)-penicillanicacid

I sobuty l-chlorof ormate (0.13 ml, 1 mmol) was added dropwise at -10°C to a vigorously stirred solution of [2,2-bis- (diethoxy-phosphory 1 )-ethy lsul fany 1 ]-acet ic acid (0.39 g, 1 mmol) and 2 , 6-dimethy lpyridine (0.11 ml, 1 mmol) in dry tet rahydrofurane

(^ rn 1 ^ τ*-ιo > i tn p wa σ ho 1 H at -lO'c for 1 S rn i m« * P c tn rnmolptp formation of the mixed isobutoxyf ormic anhydride. An ice-cold solution of amoxicillin (0.42 g, 1 mmol) and 2 , 6-dimethy lpyr idine (0.17 ml, 1.5 mmol) in a 1:1 mixture of tetrahydrof urane and water (6 ml) was added rapidly, and the mixture was stirred at 0'C to 5°C for 1 hour and then for a further 1 hour while it attained room temperature. Tet rahydrofurane was removed under reduced pressure, then the residue was dissolved 'n 20 ml water. The slightly basic (pH=7.5) aqueous solution was extracted with ethyl acetate (3 x 15 ml), and the organic phase was set aside. The aqueous phase was cooled to 0 " , acidified to pH=2.5 with 0.1 M HC1, and extracted with ethyl acetate (3 x 30 ml). The organic phase was dried over MgSO, and the solvent evaporated to give 0.35 g (48%) crystalline product. , .p. : 104-106°C. Ana I . :

Calc ^* d. for C ₂₈ H ₄₁ N,0,,P, S, C, 45.46; H, 5.86, N, 5.68; P, 8.37 Found C, 45.80; H, 6.18; N, 5.66; P, 8.20

IR: 1786 cm ^"1 (β-lactame C=0)

FAB_MS: 739 ( M+ )

Η-NMR (200 MHz, in DMSO): δ: 5.7 (dd, 1 H, H-6); 5.4 (d, 1 H,

H-5); 4.1 (m, 8 H, P ( 0 ) CH _j CH _j ) ; 1.2 (m, 12 H, P(0)CH ₂ CH ₃ )

EXAMPLE 3

2 ■ 2-Bis-( dimethoxyphosphory 1 ) -ethyl sul f any 1-acet ic acid

Following the procedure of Example 1 A but substituting for tetraethyl ethylidenephosphonate an equivalent amount of tetramethyl e thy 1 idenephosphonate , the title compound is obtained.

EXAMPLE 4

2,2-Bis-(dipropoxy hosphoryl )-ethylsulfanyl-acetic acid

Following the procedure of Example 1 A but substituting for tetraethyl e thylidenephosphonate an equivalent amount of tetra- n-propy 1 ethy 1 idenephosphonate , the title compound is obtained.

EXAMPLE 5

The MIC values (μg/ml) of the compound of Example 1 B and of norfloxacin were determined against various organisms by the agar dilution method with the following results.

EXAMPLE 7

7-( 4-( 2, 2-Bis-phosphonoethyl )-piperazin-l-yl)-l-ethyl- 6-fluoro-4-oxo-l , 4-dihydroquino line-3-carboxylic acid

To a solution of 7- ( 4- ( 2 , 2-bi s-diethoxy-phosphory 1 ) - ethyl-6-fluoro-4-oxo-l , 4-dihydroquino line-3-carboxylic acid (mmo 1 ) in dry dichloromethane (10 ml) bromotrimethy Is i lane (1.3 ml, 10 mmol was added and the mixture was reacted for three days at room temperature. It was then evaporated to dryness and water (10 ml) was added to the residue. It was stirred for one day and evaporated. Di hloromethane (10 ml) was added, and it was stirred overnight. The product was then recovered by filtration and dried in vacuum to yield 0.42 g (62.7%). M.p. 205°.

Η-NMR :δ(D,0) 8.48 (1H, s, H-2); 7.53 (1H, d. H-5); 7.0 (1H, d,

H-8); 4.35 ^" (2H, q, CH,CH,N); 3.6 (10H, m, piperidine + NCH _j CH) o (1H, m, CHP); 1.5 (3H, t , CH ₃ CH ₂ N ) .

Anal. : Cal.c'd. for C,„H,,FN,O _q P,x2HBr (669.36):

C, 32.29; ^' H, 3.91; N, 6.28; P, 9.26. Found: C, 32.42; H, 4.24; N, 6.13; P, 9.47.