Field of the Invention

The present invention relates to unsaturated azabicyclo- amine compounds and processes for the preparation thereof, and, more specifically, to unsaturated azabicycloaαine compounds useful as an intermediate for preparing quinolone carboxylic acids, cephalosporin compounds, and other rel related antioacterial compounds; and to novel processes for preparing these compounds and the salts thereof.

Description of the Prior Art

In the process of developing novel medicinal compounds which possess a broad spectrum of potent anti-bacterial activities and are effective against various microorganisms, needs have existed for the discovery of novel intermediates capable of producing such compounds having improved antibacterial activities.

Japanese Patent Publication No. Hei 02-78659 discloses saturated azabicycloamine compounds whose molecular structure are bent for the reason that its rings are linked in cis form.

Consequently, the antibacterial compounds prepared therefrom did not exhibit sufficient antibacterial activity.

Summary of the Invention

The present inventors have discovered that certain unsaturated azabicycloamine compounds which do not have stereoisomers relating to the form of their rings but have a planar molecular shape are useful for preparing various different antibacterial compounds such as cephalosporin and quinolone carboxylic acid derivatives with improved activities.

Accordingly, the present invention primarily pertains to providing novel azabicycloamine compounds useful as intermediate compounds for preparing such diverse and effective antibacterial compounds; and novel processes for-the preparation thereof.

Detailed Description of the Invention

The present invention relates to the azabicycloamine compounds, and their salts represented by the formula(I):

wherein: .

R is a hydrogen atom or an amine protecting group;

Ri and R2, which may be the same or different, are hydrogen,.

optionally substituted lower alkyl, alkanoyl, optionally substituted benzoyl or naphthoyl, optionally substituted alkoxycarbonyl, or optionally substituted benzyloxycarbonyl; and n is an integer from 1 to 4.

The amine protecting group of R in formula (I) may be benzenesulfonyl, paratoluenesulfonyl, methanesulfonyl, C^-alkoxycarbonyl, benzyloxycarbonyl, paranitrobenzyloxycarbonyl, 2,2,2-trichlorethoxycarbonyl, C^-alkanoyl, or optionally substituted behzoyi or naphthoyl; R. or R ₂ may be optionally substituted lower alkyl, such as C ₇ -, preferably C^-alkyl, especially methyl or ethyl, alkanoyl, preferably C^-alkanoyl, including formyl, acetyl, propionyl, butanoyl, pentanoyl, hexanoyl, heptanoyl, octanoyl, decanoyl, undecanoyl, palmitoyl, oleoyl, stearoyl and cyclohexanoyl, optionally substituted benzoyl or naphthoyl, optionally substituted alkoxycarbonyl, preferably C^-alkoxycarbonyl, such as ethoxycarbonyl, and 2,2,2- trichloroethoxycarbonyl, or optionally substituted benzyloxycarbonyl, such as paranitrobenzyloxycarbonyl.

Another aspect of the present invention relates to an acid addition salt of the compound of formula (I) wherein at least one nitrogen atom is basic nitrogen, which may include the salts of an inorganic acid such as hydrochloric, hydrobromic, phosphoric, or sulfuric acid, and of an organic acid such as formic, acetic, propionic, methane sulfonic, trichloroacetic, trifluoroacetic, lactic, maleic, malonic, fumaric, citric, tartaric, paratoluene sulfonic, benzene sulfonic, palmitic, oleic or stearic acid.

The process for preparing the compound of formula (Ia-1) may be summarizedby the following Scheme(A):

Scheme(A)

(Ia-1) σ-«

wherein: n is an integer from 1 to 4; R ₁₀ is a C^-alkyl group;

R ₃ an amine protecting group, such as e.g. methoxycarbonyl, ethoxy¬ carbonyl, t-butoxycarbonyl, 2,2,2-trichioroethoxycarbonyl, benzyloxycarbonyl, or paranitrobenzyloxycarbonyl; R ₄ has the same definition as R in formula (I), especially benzenesulfonyl, paratoluenesulfonyl, methanesulfonyl, or C^-alkoxycarbonyl; X is iodine, bromine or chlorine, or a O-mesyl or O-tosyl grou; and A is hydrochloric, hydrobromic, sulfonic or trifluoroacetic acid.

The compound of formula (IV) may be prepared by reacting sodium azide with the compound of formula (III) which may be prepared by heating the compound of formula (II) with N-bromo(or chloro) succinimide in the presence of a free radical-generating agent such as benzoyl peroxide or AIBN (aziisobutyronitrile). The compound of formula (V) is prepared by reacting the compound of formula (IV) with thphenylphosphine in the presence of a solvent of tetrahydrofuraπ and water; and, thereafter, the compound of formula (VI) is prepared by reacting the compound of formula (V) with an amine protecting agent such as di-t-butyl dicarbonate or methyl (or ethyl-, trichioromethyl-, benzyl- or paranitrobeπzyl-) chloroformate in the presence of base such as pyridine, triethylamine, sodium hydride, sodium hydroxide, or potassium carbonate.

The compound of formula (VI) is reduced with an ester reducing agent such as diisobutylaluminium hydride to obtain the alcohol of formula (VII), which is subsequently reacted with a halogeπation agent such as phosphorous trichloride, phosphorous trifluoride, thionylchloride or oxalkyl chloride, or reacted with triphenylphosphine and carbon tetrachloride or carbon tetrabromide.

The compound of formula (IX) can be prepared by reacting the compound of formula (VIM) with an R ₄ donating agent such as paratoluenesulfonamide, benzenesulfonamide, acetamide, benzamϊde, methanesulfonamide and urethane in the presence of a base such as sodium hydride, triethylamine or potassium carbonate.

The compound of formula (IX) is heated in hydrochloric acid, sulfuric acid, hydrobromic acid or trifluoroacetic acid to obtain the compound of formula (la-1); and may also be used for preparing the compound of formula (1-1) by removing the amine protecting group in the presence of a base such as sodium hydroxide or sodium ammonia.

The compound of formula (I) wherein R and R _n are hydrogen and R ₂ is lower alkyl (compound I-2, la-2) can be prepared in accordance with the following Scheme (B):

Scheme(B)

wherein: n, Rio, R2 , R3 and A have the same meanings as defined previously.

In Scheme(B), a compound of formula(X) is obtained by reacting the compound of formula(III) with sodium acetate or silver acetate, and a compound of formula(X) is subsequently deacetylated to give the compound of formula(XI).

The compound of formula(XI) is tosylated or esylated, which subsequently is either reacted with a.- R ₂ donating amine compound or undergoes a Mitsunάbu reaction so as to Droduce a compound of formula(XII).

Protecting the nitrogen atom of formula(XII) with an amine protecting agent by employing the same method as used for the preparation of compound of formula(VI), the compound of formula(I-2). or (Ia-2) is prepared by repeatin the process of preparing the compound of the formula(I-l) or (Ia-1).

Further, the compound of formula(I) wherein R and - are hydrogen and 2 is 9. lower alkyl group may be preoared by eπploying the method of Scheme (C) given below:

Scheme (C)

CIa-3)

wherein: n, R2, R3, R4 and A have the same meanings as defined previously.

In Scheme(C), the compound of formula(IX) is reacted with an alkylhalide in the presence of a strong base such as sodium

hydride to obtain the compound of formula(XIV), from which 3 and R4 , the amine protecting groups are removed to produce the compound of formula(I-3) or (Ia-3).

Further, the compound of formula(I) wherein Ri is a methyl group may be prepared by reducing the compound of formula (XV) in the presence of aluminium lithium hydride to obtain the compound of formula(XVI) and removing Re therefrom as shown in the following Scheme(D):

Scheme(D)

σa-4) wherein: n, A, R2 and R3 have the same meanings as previously defined; and

Re is a (para)toluenesulfonyl or methanesulfonyl group.

More specifically, the compound of formula(I), wherein one of Ri and R2 is a methyl group and the other is a hydrogen atom, can be prepared by employing the following Scheme(E):

SchemeCE)

Clα-5)

wherein: n, A, R3 and Rε have the same meanings as previously defined; and

Rs is a (para)toluenesulfonyl or methanesulfonyl group.

The compound of the formula(I-δ) or (Ia-5) can be obtained by reducing R3 in the compound of formula (XVII) to a methyl group j-n the presence of lithium aluminium hydride to give the compound of formula(XVIII) and by way of removing Rε therefrom.

The following examples are intended to further illustrate the present invention, without limiting the scope of the invention.

Example 1: Synthesis of 3-bromo-l-cyclopentene-l,2-dicarboxylic acid dimethylester

To a solution of 18g of l-cyclopentene-l,2-dicarboxylic acid dimethylester dissolved in 180mfl of carbon tetrachloride were added 17. g of N-bromosuccinimide{NBS) and 1.6g of ,α-azobis (isobutyronitrile)(AIBN); and the resultant mixture was refluxed for 5 hours. After filtering the reaction mixture, the filtrate was

concentrated under a reduced pressure and purified by fractionating on the silica gel column chromatography to obtain 18.8g of the title compound in yellow oil(yield 73%) .

MS m/z(rel. int, %) : 263(M ⁺ , 43) , 231(23) , 183(100) ,

151(63 )

¹ H-NMR(CDC13 , (J pm) : 2.45(1H, m) , 2.57( 1H, m) , 2.7

( 1H, m) , 3.05 (1H, ) , 3.73(6H, s) , 5.25 (1H, )

Example 2: Synthesis of 3-azido-l-cyclopentene-l,2-dicarboxylic acid dimethylester

To a solution of 18g of 3-bromo-l-cyclopentene-l,2- dicarboxylic acid dimethyl ester dissolved in 200ra£ of carbon

• tetrachloride was added a solution of 15.6g of sodium azide dissolved in 65mδ of water; and the resultant solution was stirred for 16 hours. The reaction solution was refluxed for 1 hour and cooled; and the organic layer was separated. After the remaining aqueous layer was extracted twice with carbon tetrachloride, the organic layers were combined, dried over anhydrous magnesium sulfate and concentrated under a reduced pressure to obtain 13.4g of the title compound in yellow oil(yield 92X).

MS m/z(rel. int, X): 226(M , 3.3), 187(67), 151(100),

138(45), 106(30), 93(27), 68(27)

¹ H-NMR(CDCl3, δ ppm): ^' 2.0(1H, m), 2.4(1H, m), 2.67(1H, m ) ,

2.9{1H, m), 3.8(6H, s), 4.77(1H, m)

Example 3: Synthesis of 3-amino-l-cyclopentene-l,2-dicarboxylic acid dimethylester

To a solution of 13.4g of 3-azido-l-cyclopentene-l,2-

dicarboxylic acid dimethyl ester dissolved in 135mfi of tetrahydro furan was added 15.5g of triphenylphosphine; and the resultant mixture was stirred for 16 hours under nitrogen gas.

After adding 1.6m£ of water, the reaction mixture was stirred for 5 hours at a room temperature and concentrated under a reduced pressure; and the residue was dissolved in 250m£ of dichloromethane. The reaction solution was extracted with 350mfi of 2N hydrochloric acid, and, then, the aqueous layer was separated and neutralized with 15% aqueous NaOH solution.

The aqueous solution was extracted with 300mβ of dichloro¬ methane, dried over anhydrous magnesium sulfate and concentrated under a reduced pressure to obtain 5.9g of the title compound in pale yellow oil(yield 50%).

MS m/z(rel. int, %); 199(M÷, 4), 184(3.5), 152(15), 140

(100), 108(28); 80(55)

¹ H-NMR(CDCl3, ppm): 1.6(2H, ) , 2.4(1H, m), 2.6(1H, m),

2.75(1H, m), 3.7(1H, ), 3.73(3H, s), 3.75(3H, s), 4.2(1H, )

Example 4: Synthesis of 3-t(N- ~bu--c^car-t--c-ιy )aσ±nor1-- cyclopentene-l,2-dicarboxylic acid dimethylester

To a solution of 5.9g of 3-amino-l-cyclpentene-l,2- dicarboxylic acid dimethylester dissolved in 80mfl of ethanol was added 7.1g of di-t-buthyl dicarbonate, and the resultant mixture was strirred for 16 hours at room temperature. The reaction mixture was concentrated under the reduced pressure and fractionated on silica gel column chromatography to obtain 8.42g of the title compound in white precipitate(yield 95%).

MS m/z(rel. int, %): 300(M ⁺ , 28), 244(88), 200(38), 183 (49), 167(53), 140(46), 57.(100)

ⁱ H-NMR(CDCl3, tfppm): 1.4(9H, s), 1.73(1H, m), 2,8-2.4

(3H, m), 3.74(3H, s), 3.76(3H, ε), 4.76(1H, br.s), 5.03(1H, br.s)

Example 5: Synthesis of 3- (N-t-butαxycarbonyl)aτnino-1 ,2-bis (hydroxymethyl)-l-cyclopentene

A solution of 18g of diisobutylaluminium hydride dissolved in lOO fi of anhydrous tetrahydrofuran was cooled to -78'C and, then, a solution of 9.4g of 3-amino(N-t-butoxycarbonyl) mino-1- cyclopentene-l,2-dicarboxylic acid dimethyl ester dissolved in 90mC of tetrahydrofuran was added dropwise thereto for 1 hour. The resultant solution was stirred for 2 hours; and 9mfi of methanol and 3mβ of water were added carefully thereto.

The reaction mixture was extracted with 50% solution of methanol and dichloromethane(l:1, v/v) and concentrated under a reduced pressure to obtain 3.03g of the title compound in pale yellow oil(yield 40%).

MS m/z(rel. int, %): 243(M* )

¹ H-NMR(CDCl3, cϊppm): 1.39(9H, s), 1.45(1H, m), 2.5~2.25

(3H, m), 4.03UH, m), 4.2(4H, m) , 4.68UH, m)

Example 6: Synthesis of 3- (N-t-butc^c^rbonyl)ar- no-l ,2-bis (bromo ethyl)-l-cyclopentene

To a solution of 3.03g of 3-amino(N-t-butoxycarbonyl)amino- l,2-bis(hydroxymethyl)-l-cyclopentene and 9.94g of carbon tetrabromide dissolved in 30mβ of dichloromethane was added dropwise for 10

minutes a solution of 9.8g of triphenylphosphine dissolved in 20mfi of dichloromethane, in a cold water bath. The resultant solution was stirred for 30 minutes in a cold water bath and concentrated under the reduced pressure; and the residue was dissolved in ethyl- ether, which was filtered for the removal of undissolved solids. The filtrate was concentrated under a reduced pressure and purified by fractionating on the silica gel column chromatography to obtain 1.85g of the title compound in white precipitate(yield 40%). m.p. : 104° ~ 106°

MS m/z(rel. int, %): 369(M÷), 312(50), 253(22), 234(90),

188(15), 152(100), 108(27), 91(23), 57(55) ⁱ H-NMR CDC , S ppm) : 1.58(9H, s) , 1.65(1H, m) , 2.35- 2.65

(3H, m) , 4.03C4H, ) , 4.61(1H, br.s) , 4.88C1R, br. s)

Example 7: Synthesis of 3- (N-t-butccςycarbonyl)amino-1,2-bis (chloromethyl)-l-cyclopentene

To a solution of 3.03g of 3-amino(N-t-butoxycarbonyl)- l,2-bis(hydroxymethyl)-l-cyclopentene dissolved in 30πώ of carbon tetrachloride was added 6.86g of triphenylphosphine; and the resultant mixture was refluxed for 3 hours. The reaction mixture was concentrated under a reduced pressure and fractionated on the silica gel column chromatography to obtain 1.21g of the title compound in white precipitate(yield 35%). m.p. : 85 ^c —88°

MS m/z(rel. int, %): 377(M\ 5), 222(85), 187(70), 163(50),

152(95), 127(27), 91(45), 57(100)

ⁱ H-NMRfCDCls , tfppm): 1.39(9H, s), 1.6(1H, m), 2.4-2.6

(3H, m), 4.1(4H, ), 4.5(1H, br.s), 4.8(1H, br.s)

Example 8: Synthesis of 6- (N-t-butαxycarbonyl)amino-3-

(paratoluenesulfonyl)-3-azabicyclo[3,3,0]oct-l(5)ene

To a solution of 1.85g of 3-amino(N-t-butoxycarbonyl) amino-l,2-bis(bromomethyl)-l-cyclopentene and 943mg of paratoluene sulfona ide dissolved in 20mC of dimethylformamide was added 500mg of sodium hydride(55— 60%) in a cold water bath. The resultant mixture was stirred for 5 hours; and 60m£ of water was added thereto. The reaction solution was, then extracted with dichloromethane, concentrated under a reduced pressure and purified by fractionating on the silica gel column chromatography to obtain 950mg of the title compound in white precipitate(yield 50%). m.p. : 159° - 160 ^* C

MS m/z(rel. int, %): 378(M ⁺ , 0.5), 321(18), 260(95), 234

(20), 167(100), 155(17), 106(93), 91 (27), 80(18), 57(17) ⁱ H-N RfCDCls, Sppm): 1.5(9H, s), 1.88(1H, m), 2.09

(1H, m), 2.20(1H, m), 2.44(3H, s), 2.69(1H, s), 3.99(4H, br.s), 4.4S (1H, br.m), 4.56(1H, br.s), 7.31(2H, d, J=8Hz), 7.73(2H, d, J=8Hz)

Example 9: Synthesis of 6-amino-3-azabicyclo[3,3,0]oct-l(5)ene dihydrobromide

To a solution of 760mg of 6-amino(N-t-butoxycarbonyl)amino- 3-(paratoluenesulfonyl)-3-azabicyclooct-l(5)ene dissolved in 2.6mδ of 30% aqueous hydrobromide was added 430mg of phenol. The resultant

mixture was refluxed for 5 hours; and 60mfi of water was added thereto.

The reaction mixture was washed with chloroform until any color did not remain in the chloroform layer. The aqueous layer was separated, decolorized by the filtration through by using active carbon, and

. concentrated under a reduced pressure. The residue was suspended in a solvent of ethanol and ehtylether(l:2, v/v) to give 330mg of the title compound in white precipitate(yield 65%). m.p. : 195° -198 ^* C .

MS m/z(rel. int, %): 124(M ⁺ , 7), 107(100), 95(33), 82(53),

80(90) ⁱ H-NM CCDCls , cJ ppm) : 2.1- 2.8(4H, m) , 3.95(2H, s) , 3.96

(2H, s) , 4.29(1H, )

Example 10: Synthesis of 6-methylamino-3-(paratoluenesulfonyl)-3- azabicyclo[3,3,0]-oct-1(5)ene

To a solution of lOOmg of 6-amino(N-t-butoxycarbonyl)-3-

(paratoluenesulfonyl)-3-azabicyclo[3,3,0]oct-1(5)ene dissolved in

3m-! of tetrahydrofuran was added 23mg of lithium aluminium hydride.

The resultant mixture was refluxed for 20 minutes; and lOπώ of methanol and O.lmfi of water were added thereto. The reaction mixture was extracted with 50% ^" solution of ^" methanol/dichloromethane(l:l, v/v), concentrated under a reduced pressure and purified by fractionating on the silica gel column chromatography to obtain 70mg of the title compound in white precipitate(yield 83%).

MS m/z(rel, int, %): 292(M ⁱ H-NMRfCDCls , c? ppm) : 1.89(1H, m) , 2.13(1H, m) , 2.23(1H, br. s) , 2.24(3H, s) , 2.46(1H, m) , 2.52 (3R, s) , 3.66(1H, br.m) , 3.84- 4.16 (4H, m) , 7.27(2H, d, J=8Hz) , 7.63(2H, d, J=8Hz)

Example 11: Synthesis of 6-methylamino-3-azabicyclo[3,3,0]oct-l(5) ene dihydrobromide

A solution of 70mg of 6-methylamino-3-(paratoluene- sulfonyl)-3-azabicyclo[3,3,0]oct-l(5)ene suspended in 0.2mfi of hydrogen bromide was refluxed for 5 hours; and lOmfi of water was added thereto. The reaction mixture was washed with chloroform until any color did not remain in the chloroform layer. The aqueous layer was separated, decolorized by being filtered through active carbon, and concentrated under a reduced pressure. The residue was suspended in a solvent of ethanol and ethylether(l:2, v/v) to obtain 40mg of the title compound in white precipitate(yield 55%).

MS m/z(rel. int, %): 138(M ⁺ , 7), 107(100), 94(18), 80(55),

68(12)

¹ H-NMR(CDCl3, <?ppm): 2.2- 2.8(4H, ^' m) , 2.51(3H, s), 3.96

(4H, m), 4.22(1H, br.m)

Example 12: Synthesis of 6-(N-t-butoxycarbonyl-N-ethyl)amino-3- (paratoluenesulfonyl)-3-azabicyclo[3,3,0]oct-1(5)ene

To a solution of 1.89g of 6-amino(N-t-butoxycarbonyl)-3- (paratoluenesulfonyl)-3-azabicyclo[3,3,0]oct-l(5)ene dissolved in 20mfi of dimethylformamide in nitrogen environment was added 280mg of sodium hydride. The resultant mixture was stirred for 2 hours at room temperature; and 850mg. of ethyliodide was added thereto. The reaction mixture was stirred for 5 hours, concentrated under a reduced pressure and purified by fractionating on the silica gel column to obtain 1.73g of the title compound(yield 85%).

iH-NMR(CDCl3 , tf ppm) : 1.45(3H, t, J=7Hz) , 1.89- 2.05

(2H, m) , 2.21(1H, m) , 2,46(3H, s) , 270(1H, π) , 4.0K4H, br. s) , 4.20(2H, q, J=7Hz) , 4.47(1H, ) , 7.30(2H, d, J=8Hz) , 7.74(2H, d, J=8Hz)

Example 13: Synthesis of 6-ethylamino-3-azabicyclo[3,3,0]oct-l(5)- enedihydrobromide

406mg of 6-(N-t-butoxycarbonyl-N-ethyl)amino-3- (paratolue esulfonyl)-3-azabicyclo[3,3,0]oct-l(5)ene and lOOmg of phonol were suspended in 10m2 of 30% hydrogen bromide solution. The resultant mixture was refluxed for 5 hours, cooled and washed 5 times with 20 £ of chloroform. The aqueous solution was decolorized by using active carbon, filterted and concentrated. The residue was solidified in a mixture solution of ethanol and ethylether(l:2 v/v) to obtain 200mg of the title compound in white precipitate(yield 63%). m.p.: 185° - 188'C

¹ H-NMR(CDCl3 , tf ppm) : 1.40(3H, t, J=7Hz) , 2.50- 2.81

(4H, m) , 3.94(4H, br.s) , 4.18(2H, q, J=7Hz ) , 4.24UR, m)

Example 14: Synthesis of 6-(N-ethyl-N-methyl)amino-3-(paratolύene- sulfonyl)-3-azabicyclo[3,3,0]oct-l(5)ene

To a solution of 400mg of 6-(N-t-butoxycarbonyl-N-ethyl) amino-3-(paratoluenesulfonyl)-3-azabicyclo[3,3,0]oct-l(5)ene dissolved in 10m£ of tetrahydrofuran was added lOOmg of lithium aluminium hydride. The resultant mixture was refluxed for 25 minutes; and lOmfi of methanol and 0.5mi of water were added thereto.

After the reaction mixture was filtered, the filtrate was concentrated under a reduced pressure and purified by fractionating on the silica gel column to obtain 250mg of the title compound

(yield 75%)

1H-NMR(CDC13, t?ppm): 1.42(3H, t, Js7Hz), 1.90(1H, a),

2.17-2.20(2H, m) , 2.23(3H, s), 2.43 (1H, m), 2.53(3H, s), 3.71(1H, m), 3.95(4H, br.s), 4.24(2H, q, J=7Hz), 7.26(2H, d, J=8Hz), 7.64(2H, d, J=8Hz)

Example 15: Synthesis of 6-(N-ethyl-N-methyl)amino-3-azabicyclo [3,3,0]oct-1(5)ene dihydrobromide

160mg of 6-(N-ethyl-N-methyl)amino-3-(parotoluenesulfonyl)- 3-azabicyclo[3,3,0]oct-l(5)ene was suspended in 5raJ2 of 30% hydro¬ bromide solution; and the resultant mixture was refluxed for 5 hours followed by addition of lO fi of water. The reaction mixture was washed with chloroform; and the aqueous layer was separated, decolorized by being filtered through active carbon and concentrated under a reduced pressure. The residue was suspended in 20m£ ^' of a mixture of ethanol and ethylether(l:2, v/v); and the precipitates produced therefrom subsequently filtered and dried to obtain 123mg of the title compound(yield 75%). m.p.: 165° - 168'C ^l H-NMR(D2θ, ppm); 1.42(3H, t, J=7Hz), 2.25(3H, s),

' 2.51~2.80(4H, ), 3.90(4H, br.s), 4.15(2H, q, J=7Hz), 4.21(1H, m)

Example 16: Synthesis of 3-bromo-l-cyclohexene-l,2-dicarboxylic acid dimethylester

To a solution of 18g of l-cyclohexene-l,2-dicarboxylic acid dimethylester dissolved in 180mfi of carbon tetrachloride were added 16.lg of N-bromosuccinimide and 1.49g of α ,α-azobis (isobutyronitrile); and the resultant mixture was refluxed for 5 hours. The reaction mixture was filtered, concentrated under a reduced pressure and fractionated on the silica gel column chromato¬ graphy to obtain 17.6g of the title compound(yield 70%). MS m/z(rel. int, %): 277(M÷) ⁱ H-NMR(CDCl3, dppm): 5.23(1H, ), 3.81(6H, ε), 3.1(1H, ), 2.7—2.4(3H, m), 1.51(2H, )

Example 17: Synthesis of 3-azido-l-cyclohexene-l,2-dicarboxylic acid dimethylester

To a solution of 17g of 3-bromo-l-cyclohexene-l,2- dicarboxylic acid dimethylester dissolved in 180mfi of carbon tetrachloride was added a solution of 14g of sodium azide dissolved in 55rafi of water; and the resultant mixture was stirred for 16 hours at room temperature. The reaction mixture was refluxed for 1 hour and cooled; and the organic layer was separated, and the remaining aqueous layer was extracted twice with carbon tetrachloride. All the organic layers were conbined, dried over anhydrous magnesium sulfate, and concentrated under a reduced pressure to obtain 13.4g of the title compound in yellow oil(yield 91%).

MS m/z(rel. int, %): 240(M ⁺ )

ⁱ H-NMR(CDCl3, Sppm): 4.79( H, m), 3.79(6H, s), 2.9(1H, ), 2.7(1H, ), 2.41(1H, m), 2.1 (1H, m), 1.45(2H, m)

Example 18: Synthesis of 3-amino-l-cyclohexene-l,2-dicarboxylic acid dimethyl ester

To a solution 13.4g of 3-azido-l-cyclohexene-l,2- dicarboxylic acid.dimethylester dissolved in 135mfi of tetrahydrofuran was added 14.5g of triphenylphosphine. The resultant mixture was stirred for 16 hours under nitrogen gas; and 1.55m£ of water was added thereto. The reaction mixture was further stirred for 5 hours at a room temperature and concentrated under a reduced pressure; and the residue was dissolved in 240mC of dichloromethane. The solution was extracted with 350 fi of 2N hydrochloric acid solution; and the aqueous layer was separated therefrom and neutralized with 15% NaOH solution. The neutralized solution was extracted with 300mfi of dichloromethane, dried over anhydrous magnesium sulfate and concentrated under a reduced condition to obtain 5.7g of the title compound in pale yellow oil(yield 48%).

MS m/z(rel. int, %): 213(M ⁺ )

¹ H-NMR(CDCl3, ppm): 4.21(1H, m), 3.73(3H, s), 3.72(3H, s), 3.56(1H, m), 2.75(1H, m) , 2.6 (1H, m), 2.4K1H, ), 1.49(2H, m)

Example 19: Synthesis of 3-(N-t-butcκyc^bσπγl)aιninc - cyclohexene-l,2-dicarboxylic acid dimethylester

To a solution of 5.7g of 3-araino-l-cyclohexene-l,2- dicarboxylic acid dimethylester dissolved in 80mfi of methanol was

added 6.4g of di-t-butylcarbonate. The resultant mixture was stirred for 16 hours at a room temperature, concentrated under a reduced pressure and fractionated on the silica gel column chromato¬ graphy to obtain 7.95g of the title compound in white precipitate (yield 95%).

MS m/z(rel. int, X): 314(M*) iH- MRCCDCls , δ ppm) : 5.09(1H, br.s) , 4.71(1H, br. s) ,

3.74(3H, s) , 3.73(3H, s) , 2.75(1H, ) ,

2.6K1H, m) , 2.43(1H, ) , 1.48(2H, m) ,

1.43(9H, s)

Example 20: Synthesis of 3-(N-t-butα^carbonyl)amino-1,2-bis (hydroxymethyl)-1-cyclohexene

14.4g of diisobutylaluminium hydride was dissolved in 90mfi of anhydrous tetrahydrofuran; and the solution was cooled to -78°C .

Thereafter, a solution of 7.9g of 3-amino(N-t-butoxycarbonyl)amino- l-cyclohexene-l,2-dicarboxylic acid dimethylester dissolved in 80m£ of tetrahydrofuran was added dropwise to the cooled solution for

1 hour, which was stirred for 16 hours at a room temperautre.

8mδ of methanol and 2.7m! of water were added carefully to the reaction mixture, which was extracted with 200mfi of 50% solution of methanol/dichloromethaήe(l:l, v/v) and concentrated under a reduced pressure to obtain 2.78g of the title compound in pale yellow oil

^• (yield 43%).

MS m/z(rel. int, %): 257(M*) ⁱ H- MRfCDCls , d ppm) : 4.69(1H, br. s) , 4.31— 4.05(5H, ) ,

2.55~ 2.25(3H, ) , 4.31- 4.05(5H, m) , 2.55- 2.25(3H, m) , 1.45(2H, m) , 1.41 (9H, s)

Example 21: Synthesis of 3-(N-t-butoxycarbonyl)aιainoτ-1 ,2-bis (bro omethyl)-l-cyclohexene

To a solution of 2.7g of 3-amino( -t-butoxycarbonyl)amino- l,2-bis(hydroxymethyl)-l-cyclohexene and 8.35g of carbon tetrabromide dissolved in 25mfi of dichloromethane was added dropwise a solution of 8.1g of triphenylphosphine dissolved in 20mfi of dichloromethane, in a cold water bath. The resutant solution was stirred for 30 minutes in a cold water bath and concentrated under a reduced pressure; the residue was dissolved in ethylether and filtered to remove undissolved solids; and the filtrate was concentrated under a reduced pressure and fractionated on the silica gel column chromato¬ graphy to obtain 1.65g of the title compound in white precipitate (yield 41%).

MS m/z(rel. int, %): 383(M*)

¹ H-NMR(CDCl3, tϊppm): 4.90(1H, br.s), 4.62(1H, br.s),

4.01(4H, m), 2.7-2.35(3H, m) , 1.75— 1.45(3H, m), 1.43(9H, s)

Example 22: Synthesis of 6-(N-t~butQxvOar onyl)'ajain-> ^; -3-

(paratoluenesulfonyl)-3-azabicyclo[4,3,0]non-l(5)ene

To a solution of 1.6g of 3-amino(N-t-butoxycarbonyl)amino- l,2-bis(bromomethyl)-l-cyclohexene and 785mg of paratoluenesulfonamide dissolved in 15m£ of dimethylformamide was added 416mg of sodium hydride(55— 60%) in a cold water bath; and the resultant mixture was stirred for 5 hours. After 60mfi of water is added, the reaction mixture was extracted with dichloromethane, concentrated in a reduced pressure and fractionated on the silica gel column chromatography to obtain 767mg of the title compound in white precipitate(yield 47%).

MS m/z(rel. int, %) : 392 (M* ) iH-NMR CDC , ppm) : 4.51(1H, br.s) , 4.85(1H, br.s) ,

. 4.1- 3.85(4H, m) , 2.61(1H, ) , 2.21 (1H, m) , 2.1K1H, ) , 1.73(1H, m) , 1.45(2H, m) , 1.39(9H, s)

Example 23: Syntheεis of 6-aaino-3-azabicyclo[4,3,0]non-l(5)ene dihydrobro ide -

To a solution of 760mg of 6-amino(N-t-butoxycarbonyl)amino-

3-(paratoluenesulfonyl)-3-azabicyclo[4,3,0]non-l(5)ene suspended in

2.5mfl of 30% hydrobormide solution was added 410mg of phenol; and the resultant mixture was refluxed for 5 hours. After 40m£ of water was added, the reaction mixture was washed with chloroform until any color did not remain in the chloroform layer; and the aqueous layer was filtered through active carbon, concentrated under a reduced pressure and precipitated in 30m£ of ethanol/ethylether

(1:2, v/v) solution to obtain 408mg of the title compound in white precipitate(yield 70%).

MS m/z(rel. int, %): 137(M÷)

^J -H- MRtCDCls , cT pm) : 4.29(1H, br.s) , 3.95(4H, s) , 2.79

(1H, m) , 2.45(1H, ) , 2.35(1H, ) , 2.22(1H, m) , 1.48(2H, m)

Preparation Example 1: Preparation of 7-{6-amino-3-azabicyclo[3,3,0] oct-l(5)ene-3-yl}-l-cyclopropyl-6,8-difluoro- 1,4-dihydro-4-oxoquinoline-3-carboxylic acid (Compound A)

To a mixture of 330mg of 6-amino-3-azabicyclo[3,3,0]oct- l(5)ene dihydrobromide and 320mg of 1-cyclopropy1-6,7,8-trifluoro- l,4-dihydro-4-oxoquinoline-3-carboxylic acid suspended in lOmfi of

acetonitrile was added 616μ£ of l,8-diazabicyclo[5,4,0]undec-7-ene; and the resultant mixture was stirred for 5 hours. The reaction mixture was cooled and filtered; and the residue was washed with acetonitrile to obtain 340mg of the title compound in pale yellow precipitate(yield 85%). m.p.: 213° ~215'C

MS m/z(rel. int, %): 387(M ⁺ , 20), 370(100), 343(27), 326

(73), 299(25)

¹ H-NMR(CDCl3 + CD3COOD, <?ppm): 1.26(4H, m), 2.35(1H, ),

2.52(1H, m), 2.61(1H, m), 2.90 (1H, m), 4.1(1H, m), 4.39(1H, m), 4.63(4H, br.s), 7.76(1H, dd, J=14.7, 1.5Hz), 8.75 (1H, s)

Preparation Example 2: Preparation of 7-{6-amino-3-azabicyclo[4,3,0] non-1(5)ene-3-yl}-l-cyclopropyl-6,8-difluoro- 1,4-dihydro-4-oxoquinoline-3-carboxylic acid (Compound B)

To a mixture of 400mg of 6-amino-3-azabicyclo[4,3,0]non- l(5)ene dihydrobromide and 365mg of l-cyclopropyl-6,7,8-trifluoro- l,4-dihydro-4-oxoquinoline-3-carboxylic acid suspended in lOmfi of acetonitrile was added 735μ£ of l,8-diazabicyclo[5,4,0]undec-7- ene; and the resultant mixture was refluxed for 5 hours. The reaction mixture was cooled and filtered; and the residue was washed with acetonitrile to obtain 387mg of the title compound in pale yellow precipitate(yield 75%).

MS m/z(rel. int, %): 401(M*)

^J -H- MRfCDCls + CD3COOD, tf ppm) : 8.76(1H, s) , 7.73(1H, d,

J-13Hz) , 4.68C1H, br.s) ,

4.64(4H, br. s) , 4.42(1H, br. s) , 4.10(4H, br. s) , 2.91

(1H, m) , 2.65(1H, ) , 2.55

(1H, ) , 2.35(1H, a) , 1.47

(2H, m) , 1.25(4H, )

In vitro anti-bacterial activity test

Quinolone compounds may be prepared by using a compound of formula(I) as shown in Preparation Examples. In order .to demonstrate the effectiveness of the quinolone compound prepared by using a compound of the present invention, the minimal inhibitory concentration(MIC)s of compounds A and B was determined and compared with that of ciprofloxacin. These MIC values were taken by employing two-fold dilution method; that is, two-fold serial dilutions of each of the test compounds were made and dispersed in a Mueller-Hinton agar medium; 2μfi of the standard strain which had the 10 ⁷ CFU(colony forming unit) per mδ was inoculated on the medium; and these were incubated at 37 ^* C for 20 hours. The result of the MIC tests are shown in Table 1.

Table 1: In vitro anti-bacterial activity test(MIC, μg/mfi)