JPS62252790A - Pyridobenzoxazine derivative - Google Patents

Abstract

NEW MATERIAL:The compound of formula I (R<1> and R<2> are lower alkyl; X1 is halogen). EXAMPLE:S-(-)-9-fluoro-3-methyl-10-(4-methyl-1-piperazinyl)-7--oxo-2,3 -dihydro-7H- pyrido[1,2,3-de][1,4]benzoxazine-6-carboxylic acid. USE:An antibacterial agent having remarkably excellent antibacterial activity and low toxicity compared with ofloxacin. PREPARATION:The compound of formula I can be produced by (1) condensing a dihalogeno-benzoxazine derivative of formula II (X2 is X1) used as a starting raw material with a cyclic amino acid of formula III (R3 is substituted sulfonyl, etc.; X3 is halogen, etc.) according to the reaction formula e.g. by acid chloride method, (2) separating and hydrolyzing the resultant diastereomer mixture of the compound of formula IV, (3) reacting the produced compound of formula V with ethoxymethylenemalonic acid di-lower alkyl ester and (4) converting the produced compound of formula VI through the compound of formula VII to the compound of formula I.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to antimicrobial compounds and intermediates for their production.

i kagen! Ofloxacin ((±)-9-fluoro-3-methyl-
10-(4-methyl-1-piperazinyl)-7-oxo-2,3-dihydro-7 toviride [1,2,3-del
(1,4]Benzoxazine-6-carboxylic acid (see JP-A-57-48986) is known as an excellent synthetic antibacterial agent.

The point to be solved Ofloxacin has an asymmetric carbon at the 3rd position in its structure, and the normal production method produces a racemic form ((±) form optical rotation [α
], Q”).

The present inventor obtained optically active forms of this substance, and 35 forms (
The (-) body has about twice the antibacterial activity as the (±) body, and is less toxic than the (+) body, and the 3R body ((
+) body) has an antibacterial activity of approximately 1710~t/loo, (±) body has the same degree of toxicity;
They also discovered that each optically active substance has good water solubility and can be used as an injection. Furthermore, they discovered a method for producing this optically active substance and an intermediate thereof, and completed the present invention.

The present invention is based on the formula! Compound represented by formula ■ Compound represented by formula ■ Compound represented by formula ■ Compound represented by formula ■ and compound represented by formula ■, 8F-0 xIY to human〆c0■ ×1 in the formula and x2 means a halogen atom such as fluorine or chlorine, and compounds in which both are fluorine are particularly preferred.

R1 and R2 each mean lower alkyl such as methyl, ethyl, propyl, etc., with methyl being particularly preferred.
R3 represents a substituted sulfonyl group, such as para-toluenesulfonyl, benzenesulfonyl, methanesulfonyl, an alkoxycarbonyl group, such as tertiary butoxycarbonyl, and ° represents an aralkyloxycarbonyl group, such as benzyloxycarbonyl, paramethoxybenzyloxycarbonyl. , and a substituted sulfonyl group, particularly a para-toluenesulfonyl group, is preferred. R4 represents a lower alkyl group, and RS represents a hydrogen atom or a lower alkyl group. n means an integer of 1 to 3, but usually 1 or 2 is appropriate.

The compound of the present invention can be produced by the method exemplified by the reaction formula shown on the last page.

In the chemical structural formula of the reaction formula, R,, R2, R5, R4, R5
.

That is, 3-lower alkyl-7.8-dihalogeno=1
．． The 4-benzoxazine derivative 11 and the cyclic amino acid or its reactive derivative III are subjected to an amide bond-forming reaction, such as the acid chloride method, active ester method, acid anhydride method, DC
Compound IV is produced by condensation using method C. Most commonly acid chloride III where x3 is chlorine in an organic solvent compound! The reaction may be carried out by stirring (2) at room temperature. The product can be isolated and purified using conventional methods.

In this reaction, when one of the two isomers of the cyclic amino acid or its reactive derivative 111, ie, the 5-isomer or the 8-isomer, is used, it is easy to separate the mixture of diastereomers of the compound (2). That is, derivatives of S or R-proline, S or R-pipecolic acid, etc. are suitable, and the most preferred example of compound III is (S)
-N-benzenesulfonylproline and (S)-N-
There is paratoluenesulfonylproline. A mixture of diastereomers (1) can be separated by fractional crystallization, chromatography using silica gel as a carrier, or a combination thereof.

The separated diastereomer V can be led to 3S-7,8-dihalogeno-3-lower alkyl-1,4-benzoxazine ■ by hydrolysis (usually under basic conditions), which is 35 by reacting with ethoxymethylene malonic acid di-lower alkyl ester in a known reaction.
- (7,8-dihalogeno-3-lower alkyl-2.3
-dihydro-4H-1,4-benzoxazin-4-yl)methylene malonic acid dialkyl ester ■, and heat-reacted this with polyphosphoric acid or its ester to give 3
S-9,10-dihalogeno-3-lower alkyl-7-oxo2,3-dihydro-7H-pyrido[1°2.3-
del [1,41 benzoxazine-6-carboxylic acid or its ester (1), and if necessary, after hydrolysis, this can be further reacted with N-lower alkyl biverazine to produce a 10-substituted compound. .

Alternatively, Compound (1) or Compound (2) may be converted into a trifluoroborate compound (2) and this may be reacted with N-lower alkylbiverazine to produce l0-substituted product I (Japanese Patent Application Laid-Open No. 57-46986, No. 58-297H9, No. 58
-43977, 511-72588).

Compound I can also be produced by the method exemplified below. That is, (±) -9,10-difluoro-3-
Hydroxymethyl-7-oxo-2,3-dihydro-7H
-Pyrido[1,2,3-del[1,4]benzoxazine-6-ethyl ester is treated with 3,5-dinitrobenzoic acid chloride etc. to produce (±)-3-(3,S-dinitrobenzoyl). oxy)methyl compound, which can be treated using an appropriate method such as high performance liquid chromatography (HPLC).
) to separate it into two optically active substances.

The obtained optically active substance is treated with sodium hydrogen carbonate, etc.
Hydroxymethyl compound is produced by selectively hydrolyzing the benzoyl moiety. This is converted into a 3-iodomethyl form using an iodizing reagent, and reduced with n-tributylstannane or the like to produce a 3-methyl form. This product can be hydrolyzed under acidic conditions without being purified.
[Ka] I can do it, I can do it. This is N-
When reacted with an alkylpiperazine by heating and stirring, the 1O-(4-alkyl-1-piperazinyl) form I
can be obtained.

35 optically active forms I and 3 obtained as final substances
The antibacterial activity of the R form is compared with that of ofloxacin and is shown in the table.

The test method was based on the standard method specified by the Japanese Society of Chemotherapy.

Example 1: 35-(+)-7,8-difluoro-
Dry dichloromethane (350 ml) of the acid chloride prepared from 3-methyl-4-(S) -N-p-)-luenesulfonylbroline and thionyl chloride. difluoro-3-methyl-2,3
-dihydro-48-[1,4]benzoxazine32.
8 g and 28 ml of pyridine in dry dichloromethane (3
00ml) solution while stirring at room temperature, and the mixture was further stirred at room temperature for 4 hours. The reaction solution was washed successively with 1064 hydrochloric acid, saturated aqueous sodium hydrogen carbonate solution, and saturated brine, and then dried over anhydrous magnesium sulfate.

The oily residue obtained by distilling off dichloromethane was diluted with ethyl acetate.
00ml of n-hexane while stirring.
When added dropwise little by little, crystals (compound rV:Xl
-X2-F%R1-CH3,Rs-p-Toluene JL
/honyl, n·1 (-) form) is precipitated. The precipitated crystals were filtered off, the filtrate was dried under reduced pressure, and the residue was subjected to column chromatography using 500 g of silica gel, and benzene-ethyl acetate (50:
Elution was carried out at a ratio of 1 to 25:1) to obtain an oily substance. This oil was dissolved in 500 ml of ethanol and left to stand at room temperature day and night to precipitate crystals. Diethyl ether and n-hexane were added to the crystals obtained by distilling off the ethanol, and then filtered and dried under reduced pressure to give 35- (+) -7,8-
Difluoro-3-methyl-4-[(S)-N-p-toluenesulfonylprolylco-2,3-dihydro-48-
[1,4]Benzoxazine (Compound IV: Xl-
33.4 g of X2-F, R1=CH3, Ih-f)-toluenesulfonyl, n=1 (◆) body) was obtained.

Melting point: 107-108°C (al (1+70.7° (c-0,953, chloroform) IRv: Mutual: 1685, 1510.1490
cm-' Elemental analysis value Calculated value as C21H22F2N204S C57,79H5,08N 6.42 Analysis value C
513,05H5,14N 8.47 Obtained in Example 1 (
+) 32.8 g was dissolved in ethanol IJZ, and 300 mJZ of IN sodium hydroxide solution was added thereto, followed by rapid flow for 3 hours. The oily residue obtained by distilling off the ethanol was extracted with benzene. The extract was washed with saturated brine, dried with mirabilite, and benzene was distilled off. The residue was subjected to column chromatography on 200 g of silica gel and eluted with benzene to give 5-(-
)-7,8-difluoro-3-methyl-2,3-dihydro-48-[1,4]benzoxadi:/(Vl:
X, -X, -F, R, -CH5), 12.7 g (91,
496) was obtained as an oil.

[α-9,6' (C-2,17, chloroform) The absolute configuration was determined to be S by X-ray analysis of this product as a hydrochloride.

5-(-)-Benzoxazine derivative 1 obtained in Ester Example 2
5.8 g of diethyl ethoxymethylene malonate 2
4.0 g was added and stirred for 1 hour at 130-140'C under reduced pressure. After cooling, the reaction solution was dissolved in 50 ml of acetic anhydride, and acetic anhydride-concentrated sulfuric acid (2: lv/v) was added to this under stirring while cooling with water.
80 ml of the mixed solution was added dropwise little by little. After stirring at room temperature for 1 hour, the mixture was stirred at a bath temperature of 50 to 60°C for 30 minutes. After adding ice water to the reaction solution, powdered potassium carbonate was added to neutralize it, and the mixture was extracted with chloroform. The extract was washed with a saturated aqueous sodium bicarbonate solution, then with saturated brine, and dried over Glauber's salt. Chloroform was distilled off, diethyl ether was added to the residue, and the crystals were collected by filtration to give the title compound (Vrl:Xl-X2-F
, Rs-Et) 20.0 g was obtained. Melting point 257~2
58℃ [α]. -68,1' (c-0,250,
Acetic acid-) 19.5 g of the ester obtained in Example 3 was mixed with 1 acetic acid.
50a+1, 400 ml of concentrated hydrochloric acid was added, and the mixture was refluxed for 3 hours.

After cooling, the precipitated crystals are collected by filtration, washed sequentially with water, ethanol, and diethyl ether, and dried to obtain the corresponding carbo:/fii
(WI[:Xl-X2=F, Rs=H) 16.2
g was obtained.

Melting point>300℃ [(!] D -65,66(c-0
, 985, DMSO)-6-carboxylic acid (5-(-) form of ofloxacin) Carboxylic acid obtained in Example 4 14.3
g was suspended in 600 ml of diethyl ether, 70 ml of boron trifluoride diethyl ether complex was added,
The mixture was stirred at room temperature for 5 hours. The supernatant was removed by decantation, and diethyl ether was added to the residue, which was collected by filtration, washed with diethyl ether, and then dried. Dimethyl sulfoxide 10
14.2 ul of triethylamine and 7.3 ml of N-methylpiperazine were added thereto, and the mixture was stirred at room temperature for 18 hours. The solvent was distilled off under reduced pressure, diethyl ether was added to the residue, and the yellow powder collected by filtration was mixed with 9596 methanol 400
ml, add 25 mu of triethylamine, and add 25 mu of triethylamine.
The mixture was heated to reflux for an hour. The solvent was distilled off under reduced pressure, and the residue 10 was dissolved in 500 ml of hydrochloric acid, washed three times with chloroform, and then diluted with 4N
The pH was adjusted to 11 with an aqueous sodium hydroxide solution, the pH was adjusted again to 7.3 with IN hydrochloric acid, extracted with chloroform (1×3), and dried with sodium sulfate. The crystalline solid obtained by distilling off chloroform was recrystallized from ethanol-diethyl ether to obtain the 5-(-) form of ofloxacin (I:X+=F%Rt-
12.0 g of fh-CH3) was obtained.

Melting point 226-230℃ (decomposition) [α Ko O-7H,9° (c-0,655,0,
2111 mg of S-(-)-9,10-difluoro-3-methyl-6-carboxylic acid was suspended in 30 ml of diethyl ether, and a large excess of boron trifluoride ethyl ether complex was added under stirring at room temperature.
The reaction was allowed to proceed for 45 minutes.

The precipitate was collected by filtration, washed with diethyl ether, and dried under reduced pressure to obtain the chelate compound (0 decomposition point > 300). Elemental analysis C
Calculated value as +3HaBFJO4 C47,4δ H2
,48N 4.28 analysis value C47,88H2,59N
4.32IRVW:噸720,1640.158G,
1485,1275.1035 cm-'3 of this thing
10 mg was dissolved in 6 ml of dimethyl sulfoxide, 0.32 ml of triethylamine and 0.13 ml of N-methylpiperazine were added, and the mixture was stirred at room temperature for 17 hours and then dried under reduced pressure. After washing the residue with diethyl ether, 20 ml of 9596 ethanol containing 0.5 ml of triethylamine was added.
1 and heated under reflux for 8 hours.

After cooling, the residue obtained by drying under reduced pressure was dissolved in dilute hydrochloric acid (packed) for 7H, separated from chloroform, and the aqueous layer was adjusted to p) 111 with IN sodium hydroxide, and then adjusted to p) 17.4 with IN hydrochloric acid. did. This was extracted with chloroform (50×3), dried with mirabilite, and the chloroform was distilled off. The obtained powder was recrystallized from ethanol-diethyl ether to obtain 120 mg of the target compound I in the form of transparent needle crystals. Melting point 225-227℃ Melting point 22
5-227℃ (decomposition) [a](, -76,9' (cm0.385.0.05
NNa0)! ) Elemental analysis value C+aH2oFN30
Calculated value as n・%lI20: C58,37H5,72
N 11.35 analysis value: C58,17H5,58N
11.27 Example 7: Preparation of penzoyloxy compound (±)-9,10-difluoro-3-hydroxymethyl-
7-oxo-2,3-dihydro-7H-pyrido[1,2
, 3-de] [1,4] 1 g of ethyl benzoxazine-6-carboxylate and 500 mg of pyridine were suspended in 10011 of anhydrous tetrahydrofuran (THF); 3.
Add 1.6 g of 5-dinitrobenzoyl chloride to 90
It was refluxed at °C. Once dissolved, a colorless precipitate precipitates out. After reacting for 1.5 hours, the precipitate was collected by filtration after cooling, washed with methanol and ether, and dried to obtain a colorless powder (±
) 79JO-difluoro:l-(:1,5-dinitrobenzoyloxy)methyl-7-oxo-2,3-dihydro-7H-pyrido[1,2,3-del [1,4]
Benzoxazine-6-carboxylic acid ethyl ester 1.
2g was obtained. Melting point 240-242℃ NMR (CDCl5
15! kDMso-ds) δ(ppm);1.
30(3)1. t, J-7,0) IZ, -GHz C1
13) 4.26 (2H, q, J=7.0Hz, -C!2
CH:l) 4.4-4.5 (5H, m) 7.76 (IH, dd, J-11, OHz, 7.OH
z, C6-H) 8.8 (18, S, C5-H) 9.0 (2)1. d, J-3,0 Hz, aromatic ring proton) 9.2 (IH, t, J-3,0 Hz, aromatic ring proton) Stream side 8: 6 rng of the dinitrobenzoyloxy compound obtained in Chemical Resolution Example 7 was distilled. The solution was dissolved in about 0.6 ml of dimethylformamide (DMF) purified by the above methods, filtered through a Millipore filter, and then injected into a column to perform HPL (:).

Column: Sumipax (IA-4200 (2x 2Sc
m) Solvent: n-hexane/1,2-dichloroethane/
Ethanol = 6/3/1 Flow rate: 8 ml/min The first eluted fraction (substance fraction) contains some racemic raw materials (DM
(partially hydrolyzed when dissolved in F), only the previous fraction was further subjected to silica gel chromatography and CHCl, ~to! ¥MeOH/II:)ICI
Purification was carried out using s as an elution solvent.

By repeating the purification as described above, two optically active forms 5(
-) body and R(+) body, 250 mg each were obtained.

R(+) form: retention time 56-76 minutes, column temperature 22°C
Melting point 235-240℃, [αlo + 90.8°(C
-0,852,DMF) S(-) body: retention time 7H to 9
8 minutes, column temperature 22℃, melting point 244-249℃, [α]
D-92°5° (C-0,889, DMF) S-(-)
Add 120 mg of dinitrobenzoyloxy compound to 1 ethanol
0 ml and 4 ml of saturated sodium bicarbonate solution at 50-60°C.
Heat and stir for 2 hours. After concentration, water was added and insoluble materials were collected by filtration, and washed sequentially with water, 95t ethanol, and ether to obtain S-(-)-3-hydroxymethyl compound 6 as colorless crystals.
8a+g was obtained. Melting point 235-240℃ Elemental analysis value C
Calculated value as +sH+3FJOs C55, 39, H4
,03,N 4.31 analysis value C55,44,H4,0
1,N 4.49[α ko -125,9°
(C-0,918,DMF) Similarly, R(÷)-3-hydroxymethyl compound was obtained from R(+) dinitrobenzoyloxy compound. Melting point 231-234'fQ]o
+ 125.9'(C"Q, 715.DMF
) S-(-)-3-hydroxymethyl compound (63 mg) was suspended in 12 ml of anhydrous [IMF, heated and stirred at 70 to 80°C to dissolve, and then returned to room temperature. To the obtained solution, add 340 mg of triphenylphosphite methiodite,
Stir for hours. After evaporating the solvent under reduced pressure, the residue was dissolved in chloroform and treated with an aqueous sodium thiosulfate solution and then with saturated hexachloride → 1. The mixture was dried with magnesium hydroxide and the solvent was distilled off. Diethyl ether was added to the residue and stirred, and the precipitated solid was collected by filtration, washed with diethyl ether, and dried under reduced pressure to obtain 7 Hmg of the title compound as a white powder.

Melting point 214-217℃ Elemental analysis value Calculated value as C+sH+2hIN04 C
41,40,)+2.7H. N 3.22° Analysis value (: 4L, 16. H2,58, N 2.99
Similarly, the R(+) form could be obtained.

7 Hmg of the compound of Example 10 was added to 18 m of absolute ethanol.
1, heated and stirred at 60 to 70°C to dissolve, and then returned to room temperature. Add n-tributylstannane 0 to the obtained solution.
．． 2 ml was added and stirred at 50-60°C for 1 hour and at room temperature for 1 hour. The solvent was distilled off, and the residue was subjected to column chromatography using 8 g of silica gel and eluted with chloroform-methanol (40:1) to obtain a crude methyl compound. This was dissolved in 2 ml of glacial acetic acid, 4 ml of concentrated hydrochloric acid was added, and the mixture was heated under reflux for 40 minutes. The reaction solution was concentrated, water was added, and the precipitated crystals were collected by filtration. After washing with water, ethanol and ether, the mixture was dried under reduced pressure to obtain 22 mg of crystals of the target compound. Melting point〉3
00℃ [α]. -65,6° (c-0,950,DM
SO) Elemental analysis value (: Calculated value as +JshNOa
C55,52,H3,23,N 4.98 analysis value C5
5,79,H3,20,N 4.9L (+)
I also got a body.

Cal o + as, ao (c-0,903
, DMSQ)S-(-)-9,10-difluoro-3-
Methyl-7-oxo-2,3-dihydro-7H-pyrido[1,2,3-del[1,41 21 mg of benzoxine-6-carboxylic acid and 30 mg of N-methylbiperazine were dissolved in 3 m4 of anhydrous dimethyl sulfoxide,
The mixture was stirred at 130-140°C for 1 hour. The solvent was distilled off under reduced pressure, 2 ml of ethanol was added to the residue, and the precipitated solid was collected by filtration and washed successively with small amounts of ethanol and ether.

14 mg of the obtained powder was subjected to column chromatography using 5 g of silica gel and eluted with a lower layer solution of chloroform-methanol-water (7:3:1) to obtain S-(-)-9.
-Fluoro-3-methyl-10-(4-methyl-1-piperazinyl)-7-oxo-2,3-dihydro-7H-
Pyrido[,1,2,3-del[1,4]benzoxine-6-carboxylic acid was obtained. In addition, the above-mentioned filtered mother liquor was separated and subjected to thin layer chromatography (silica gel, 20%
x 20cm, 0.5mm) and chloroform-
It was developed and purified with a lower layer solution of methanol-water (15:3:1). Both were combined to obtain 14 mg of crystals of the desired product.

Melting point 220-228℃ (decomposition) Elemental analysis value Calculated value as f+alhoFNs04 C
59,82,) 15.5B, N 11.63 Analysis value [: 60.01. H5,69,N 11.53
CaE o -aa, ao (c-0,711,0,0
5O5N-NaOH) (m/e): 361 (Mo
)NMR([;D(:13 δ(pp@):1, l1
3 (3H, d, C5-C84) 2.38 (3H, s, N
-C! ! 3) 2.54-2.60 (41 (, m, 28 岨2N) 3
．． 40~3.44 (48, m, 2X (:!2N)4
．． 35~4.52 (3H, m, C!! and C!!2
) 7.76 (III, d, aromatic TMCa-li 8.64 (
IH, s, C5-H) R (÷) body was obtained in the same manner.

Melting point 218-226℃ (decomposition) [ct]D + 88.7' (c-o, sao, 0
．． 05N-NaOH) MS (m/e): 361 (M
”) D(I Procedural Amendment dated August II, 1986)

Claims (14)

[Claims] (1) Compounds represented by the general formula ▲ Numerical formulas, chemical formulas, tables, etc. ▼ I (In the formula, R_1 and R_2 each mean a lower alkyl group) (2) S-(-)-9-fluoro-3-methyl-10-
(4-methyl-1-piperazinyl)-7-oxo-2,
3-dihydro-7H-pyrido[1,2,3-de][1
, 4] benzoxazine-6-carboxylic acid or a salt thereof; (3) General formula ▲ Numerical formula, chemical formula, table, etc. ▼ IV (In the formula, X_1 and X_2 each mean a halogen atom. R_1 means a lower alkyl group. R_3
means a substituted sulfonyl group, alkoxycarbonyl group or aralkyloxycarbonyl group, n means 1, 2 or 3) (4) X_1 and X_2 are fluorine atoms, and R_1
is a methyl group, R_3 is a substituted sulfonyl group,
The compound according to claim 3, wherein n is 1 (5) 3S-(+)-7,8-difluoro-2,3-dihydro-3-methyl-4-[(S)-N-paratoluenesulfonylprolyl]-4H-[1,4]benzoxazine The compound according to claim 3 which is (6) Compounds represented by the general formula ▲ Numerical formulas, chemical formulas, tables, etc. ▼ VI (In the formula, X_1 and X_2 each mean a halogen atom. R_1 means a lower alkyl group.) (7) X_1 and X_2 are fluorine atoms, R_1
is a methyl group, the compound according to claim 6 (8) Compounds represented by the general formula ▲ Numerical formulas, chemical formulas, tables, etc. ▼ VII (In the formula, X_1 and X_2 each mean a halogen atom. R_1 and R_4 each mean a lower alkyl group.) (9) X_1 and X_2 are fluorine atoms, R_1
is a methyl group and R_4 is an ethyl group, the compound according to claim 8 (10) General formula ▲ Numerical formula, chemical formula, table, etc. ▼VIII (In the formula, X_1 and X_2 each mean a halogen atom. R_1 means a lower alkyl group. R_5
means a hydrogen atom or a lower alkyl group. ) compound represented by (11) X_1 and X_2 are fluorine atoms, R_
The compound according to claim 10, wherein 1 is a methyl group and R_5 is an ethyl group (12) X_1 and X_2 are fluorine atoms, R_
The compound according to claim 10, wherein 1 is a methyl group and R_5 is a hydrogen atom (13) Compounds represented by the general formula ▲ Numerical formulas, chemical formulas, tables, etc. ▼IX (In the formula, X_1 and X_2 each mean a halogen atom. R_1 means a lower alkyl group.) (14) X_1 and X_2 are fluorine atoms, R_
The compound according to claim 13, wherein 1 is a methyl group