This invention relates to novel isoxazolo-pyrido-phenoxazine and isothiazolo-pyridophenoxazine derivatives having antibacterial properties and compositions containing methods of treating mammalian patients with these new derivatives.

This invention related to novel antibacterial agents and, more 
particularly, to phenoxazine derivatives having the formula: 
##STR1## 
which may exist in its tautomer form (II). 
##STR2## 
wherein B is oxygen or sulfur; and R is one or more of a hydrogen, 
halogen, C.sub.1 to C.sub.4 alkyl including halo- and hydroxy-substituted 
derivatives thereof, carboxyl, a group having the formula --Y--R.sub.1 
wherein --Y-- is --O-- or --S-- and R.sub.1 is hydrogen or C.sub.1 to 
C.sub.4 alkyl, and an amine having the formula: 
##STR3## 
wherein R.sub.2 and R.sub.3 are each independently a hydrogen or C.sub.1 
to C.sub.4 alkyl. R may also be methylenedioxy group bonded to two 
adjacent carbon atoms of the aromatic ring. 
Z is an amino group having the formula: 
##STR4## 
wherein R.sub.4 is hydrogen, C.sub.1 to C.sub.4 alkyl or 
hydroxy-substituted C.sub.1 to C.sub.4 alkyl, and R.sub.5 is alkyl or 
hydroxy-substituted C.sub.1 to C.sub.4 alkyl, an amino group, 
mono-(C.sub.1 -C.sub.4) alkylamino or di-(C.sub.1 -C.sub.4) alkylamino. 
Alternatively, Z can be an aliphatic heterocyclic ring containing 5 to 7 
atoms, and preferably 5 to 6 atoms as well as substituted derivatives 
thereof. The aliphatic heterocyclic rings preferably contain 1 to 2 hetero 
atoms which are selected from the group consisting of S, O, N and 
combinations thereof, with the remaining carbon atoms. In accordance with 
the invention, the aliphatic heterocyclic ring has the formula: 
##STR5## 
wherein R.sub.6 is selected from the group of formula (--CH.sub.2).sub.11 
-- wherein n is 2 or 3 and a group of the formula --(CH.sub.2).sub.n 
--R.sub.7 --CH.sub.2 -- wherein n is 1 or 2 and R.sub.7 is selected from 
the group consisting of --S--, --O-- and --N--. Also included are 
substituted derivatives of the above-noted aliphatic heterocyclic rings 
wherein the substituent is one or more of a C.sub.1 to C.sub.4 alkyl 
group, hydroxy-substituted C.sub.1 to C.sub.4 alkyl, amino-substituted 
C.sub.1 to C.sub.4 alkyl, hydroxy, halogen, phenyl, halophenyl, 
alkanoylamido containing 1 to 4 carbon atoms, an amine group having the 
formula: 
##STR6## 
wherein R.sub.8 and R.sub.9 are each independently selected from the group 
consisting of hydrogen, C.sub.1 to C.sub.4 alkyl. 
Illustrative of such heterocyclic groups are piperazinyl groups, 
piperidinyl groups, pyrrolidinyl groups, morpholino groups, thiomorpholino 
groups and homopiperazinyl groups (i.e., hexahydro-1-H-1,4-diazepinyl). 
As used herein, the term "halogen" refers to chloro, bromo, fluoro and iodo 
groups, while the term "C.sub.1 to C.sub.4 alkyl" refers to lower alkyl 
groups including methyl, ethyl, propyl, isopropyl, butyl, etc. 
Carboxyl refers to the --COOH group. Methylenedioxy refers to --O--CH.sub.2 
--O--group. 
The term "amino" refers to --NH.sub.2. 
The term "alkanoylamido" refers to a substituent of the formula R.sub.10 
CN-- wherein R.sub.10 is C.sub.1 to C.sub.3 alkyl, and includes but is not 
limited to acetylamino. 
The preferred compound of the invention are those having the formula: 
##STR7## 
where B is oxygen or sulfur; and R is one or more of halogen, 
methylenedioxy and and Z is piperazinyl or substituted piperazinyl, 
aminopyrrolidinyl, substituted pyrrolidinyl or substituted 
aminopyrrolidinyl, as described above. 
The chiral centers of the compounds of the invention may have either the 
"R" or "S" configuration. 
Representative of such preferred compounds, wherein B is oxygen, are 
6-(1-piperazinyl)-7-fluoro-10,11-dihydro-9H-isoxazolo[4',5':5,6]pyrido[1,2 
,3-mn]phenoxazine-9,10-dione, 
6-(4-methyl-1-piperazinyl)-7-fluoro-10,11-dihydro-9H-isoxazolo[4',5':5,6]p 
yrido[1,2,3-mn]phenoxazine-9,10-dione, 6-(3-N-ethyl aminomethyl 
pyrrolidin-1-yl)-7-fluoro-10,11-dihydro-9H-isoxazolo[4',5':5,6]pyrido[1,2, 
3-mn]phenoxazine-9,10-dione, 
6-(3-amino-1-pyrrolidinyl)-7-fluoro-10,11-dihydro-9H-isoxazolo[4',5':5,6]p 
yrido[1,2,3-mn]phenoxazine-9,10-dione, 
6-(3-methyl-1-piperazinyl)-3,7-difluoro-10,11-dihydro-9H-isoxazolo[4',5':5 
,6]pyrido[1,2,3-mn]phenoxazine-9,10-dione, 
6-(3-amino-4-methyl-1-pyrrolidinyl)-3,7-difluoro-10,11-dihydro-9H-isoxazol 
o[4',5':5,6]pyrido[1,2,3-mn]phenoxazine-9,10-dione, 
3,7-difluoro-6-(1-piperazinyl)-10,11-dihydro-9H-isoxazolo[4',5':5,6]pyrido 
[1,2,3-mn]phenoxazine-9,10-dione, 
3,7-difluoro-6-(4-methyl-1-piperazinyl)-10,11-dihydro-9H-isoxazolo[ 
4',5':5,6]pyrido[1,2,3-mn]phenoxazine-9,10-dione, 
3,7-difluoro-6-(3-amino-1-pyrrolidinyl)-10,11-dihydro-9H-isoxazolo[4',5':5 
,6]pyrido[1,2,3-mn]phenoxazine-9,10-dione, 
6-(3-aminomethyl-4-chloro-1-pyrrolidinyl)-3,7-difluoro-10,11-dihydro-9H-is 
oxazolo[4',5':5,6]pyrido[1,2,3-mn]phenoxazine-9,10-dione, 
1,3,7-trifluoro-6-(1-piperazinyl)-10,11-dihydro-9H-isoxazolo[4',5':5,6]pyr 
ido[1,2,3-mn]phenoxazine-9,10-dione, 
1,3,7-trifluoro-6-(4-methyl-1-piperazinyl)-10,11-dihydro-9H-isoxazolo[4',5 
':5,6]pyrido[1,2,3-mn]phenoxazine-9,10-dione, 
1,3,5-trifluoro-6-(3-amino-1-pyrrolidinyl)-10,11-dihydro-9H-isoxazolo[4',5 
':5,6]pyrido[1,2,3-mn]phenoxazine-9,10-dione. 
Representative of such preferred compounds, wherein B is sulfur, are 
6-(1-piperazinyl)-7-fluoro-10,11-dihydro-9H-isothiazolo[4',5':5,6]pyrido[1 
,2,3-mn]phenoxazine-9,10-dione, 
6-(4-methyl-1-piperazinyl)-7-fluoro-10,11-dihydro-9H-isothiazolo[4',5':5,6 
]pyrido[1,2,3-mn]phenoxazine-9,10-dione, 
6-(2-methyl-4-amino-pyrrolidin-1-yl)-7-fluoro-10,11-dihydro-9H-isothiazolo 
[4',5':5,6]pyrido[1,2,3-mn]phenoxazine-9,10,dione, 
6-(3-amino-1-pyrrolidinyl)-7-fluoro-10,11-dihydro-9H-isothiazolo[4',5':5,6 
]pyrido[1,2,3-mn]phenoxazine-9,10-dione, 
6-(3-methyl-1-piperazinyl)-3,7-difluoro-10,11-dihydro-9H-isothiazolo[4',5' 
:5,6]pyrido[1,2,3-mn]phenoxazine-9,10-dione, 
6-(3-amino-4-methyl-1-pyrrolidinyl)-3,7-difluoro-10,11-dihydro-9H-isothiaz 
olo[4',5':5,6]pryido[1,2,3-mn]phenoxazine-9,10-dione, 
3,7-difluoro-6-(1-piperazinyl)-10,11-dihydro-9H-isothiazolo[4',5':5,6]pyri 
do[1,2,3-mn]phenoxazine-9,10-dione, 
3,7-difluoro-6-(4-methyl-1-piperazinyl)-10,11-dihydro-9H-isothiazolo[4',5' 
:5,6]pyrido[1,2,3-mn]phenoxazine-9,10-dione, 
3,7-difluoro-6-(3-amino-1-pyrrolidinyl)-10,11-dihydro-9H-isothiazolo[4',5' 
:5,6]pyrido[1,2,3-mn] phenoxazine-9,10-dione, 
6-(3-aminomethyl-4-chloro-1-pyrrolidinyl)-3,7-difluoro-10,11-dihydro-9H-is 
othiazolo[4',5':5,6]pyrido[1,2,3-mn]phenoxazine-9,10-dione, 
1,3,7-trifluoro-6-(1-piperazinyl)-10,11-dihydro-9H-isothiazolo[4',5':5,6]p 
yrido[1,2,3-mn]phenoxazine-9,10-dione, 
1,3,7-trifluoro-6-(4-methyl-1-piperazinyl)-10,11-dihydro-9H-isothiazolo[4' 
,5':5,6]pyrido[1,2,3-mn]phenoxazine-9,10-dione, 
1,3,5-trifluoro-6-(3-amino-1-pyrrolidinyl)-10,11-dihydro-9H-isothiazolo[4' 
,5':5,6]pyrido[1,2,3-mn]phenoxazine-9,10-dione. 
Also included within the scope of the present invention are 
pharmaceutically acceptable salts of the foregoing compounds. As used 
herein, the term "pharmaceutically acceptable salts" refers to non-toxic 
acid addition salts and alkaline earth metal salts of the compounds of the 
invention. The salts can be prepared in situ during the final isolation 
and purification of the compounds of the invention, or separately by 
reacting the free base or acid functions with a suitable organic acid or 
base. Representative acid addition salts include the hydrochloride, 
hydrobromide, sulphate, bisulphate, acetate, oxalate, valerate, oleate, 
palmitate, stearate, laurate, borate, benzoate, lactate, phosphate, 
tosylate, mesylate, citrate, maleate, fumarate, succinate, tartrate 
glucoheptonate, lactobionate, lauryl sulfate salts and the like. 
Representative alkali or alkaline earth metal salts include the sodium, 
calcium, potassium and magnesium salts, etc. It has been found that the 
compounds of the present invention possess antibacterial activity against 
a wide spectrum of gram positive and gram negative bacteria, as well as 
enterobacteria. The compounds of the invention are therefor useful in the 
antibiotic treatment of susceptible bacterial infections in both humans 
and animals. In addition, the compounds, by reason of their in vitro 
activity, may be used in scrub solutions for surface inhibition of 
bacterial growth. 
Susceptible organisms generally include those gram positive and gram 
negative, aerobic and anaerobic organisms whose growth can be inhibited by 
the compounds of the invention such as Staphlococcus, Lactobacillus, 
Streptococcus, Sarcina, Escherichia, Enterobacter, Klebseilla, 
Pseudomonas, Acinetobacter, Proteus, Citrobacter, Nisseria, Baccillus, 
Bacteroides, Peptococcus, Clostridium, Salmonella, Shigella, Serratia, 
Haemophilus, Brucella, and other organisms. 
The compounds of the invention may also be formulated into compositions 
together with pharmaceutically acceptable carriers for parenteral 
injection, for oral administration in solid or liquid form, for rectal 
administration, and the like. 
Compositions according to the invention for parenteral injection may 
comprise pharmaceutically acceptable sterile aqueous or nonaqueous 
solutions, suspensions or emulsions. Examples of suitable nonaqueous 
carriers, diluents, solvents or vehicles include propylene glycol, 
polyethylene glycol, vegetable oils, such as olive oil, and injectable 
organic esters such as ethyl oleate. Such compositions may also contain 
adjuvants such as preserving, wetting, emulsifying, and dispersing agents. 
They may be sterilized, for example, by filtration through a 
bacteria-retaining filter, or by incorporating sterilizing agents into the 
compositions. They can also be manufactured in the form of sterile solid 
compositions which can be dissolved in sterile water, or some other 
sterile injectable medium immediately before use. 
Solid dosage forms for oral administration include capsules, tablets, 
pills, powders and granules. In such solid dosage forms, the active 
compound is admixed with at least one inert diluent such as sucrose, 
lactose or starch. Such dosage forms can also comprise, as is normal 
practice, additional substances other than diluents, e.g., lubricating 
agents such as magnesium stearate. In the case of capsules, tablets and 
pills, the dosage forms may also comprise buffering agents. Tablets and 
pills can additionally be prepared with enteric coatings. 
Liquid dosage forms for oral administration include pharmaceutically 
acceptable emulsions, solutions, suspensions, syrups and elixers 
containing inert diluents commonly used in the art, such as water. Besides 
such inert diluents, compositions can also include adjuvants, such as 
wetting agents, emulsifying and suspending agents, and sweetening, 
flavoring and perfuming agents. 
Compositions for rectal adminstration are preferably suppositories which 
may contain, in addition to the active substance, excipients such as cocoa 
butter or a suppository wax. 
Actual dosage levels of active ingredient in the compositions of the 
invention may be varied so as to obtain an amount of active ingredient 
effective to achieve antibacterial activity in accordance with the desired 
method of adminstration. The selected dosage level therefore depends upon 
the nature of the active compound administered, the route of 
administration, the desired duration of treatment and other factors. 
Generally, daily dosage levels of the compounds of the invention of about 
0.1 to about 750, more preferably about 0.25 to about 500 and most 
preferably about 0.5 to about 300 mg. of active ingredient per kg. of body 
weight are effective when administered orally to a mammalian patient 
suffering from an infection caused by a susceptible organism. If desired, 
the daily dose may be divided into multiple doses for administration, 
e.g., two to four time per day. 
Compounds wherein B is oxygen according to this invention can be prepared 
by the following reaction scheme in which Z and R are as described above, 
and R.sub.11 is C.sub.1 to C.sub.4 alkyl group. 
##STR8## 
In accordance with the above scheme, the substituted benzoic acid (1) can 
be converted to its acid chloride (2) by treatment with thionyl chloride. 
Displacement of the acid chloride (2) with malonic acid half ester in the 
presence of n-butyl lithium yields the beta-ketoester (3). Treatment of 
the beta-keto ester (3) with sodium hydride in non-aprotic solvent, 
preferably tetrahydrofuran with methyl N-substituted 
iminochlorothioformate (4) at room temperature or suitable elevated 
temperature as desired yields the 1,4-dihydro-4-oxo-quinoline-3-carboxylic 
acid ester (5). 
Treatment of this ester (5) with dilute acid in aqueous acetonitrile for a 
period of time gives a phenol then reacted with sodium hydride to give the 
phenoxazine derivative (6). 
Oxidation of this derivative (6) with metachlorperbenzoic acid yields the 
sulfoxide (7). The reaction may be conducted at room temperature or 
elevated temperature in the presence of non-polar solvent such as 
methylene chloride or chloroform. 
Reaction of the sulfoxide (7) with ethyl acetohydroxamate in the presence 
of a strong base such as sodium hydride or potassium t-butoxide in aprotic 
or non-aprotic solvent such as tetrahydrofuran at a temperature from 
0.degree. C. to elevated temperature yields the hydroxomate (8). Treatment 
of hydroxamate (8) with trifluoroacetic acid or dilute hydrochloric acid 
at room temperature or with perchloric acid at 0.degree. C. for a short 
time yields the free hydroxylamine derivative which is then reacted with 
sodium bicarbonate in aqueous tetrahydrofuran at room temperature or 
suitable elevated temperature to yield the 
6,7-difluoro-10,11-dihydro-9H-isoxazolo[4',5':5,6]pyrido[1,2,3-mn]substitu 
ted phenoxazine-9,10-dione derivative (9). 
Displacement of the 6-halogen of (9) with an amine (10) yields the 
6-substituted amino-isoxazolo-pyrido-phenoxazine (I). The reaction may be 
conducted at a temperature from 20.degree. C. to 130.degree. C. in the 
presence of a suitable organic polar or non-polar solvent such as 
pyridine, methylene chloride, chloroform, tetra-hydrofuran, 
1-methyl-2-pyrrolidinone, dimethyl formamide or dimethyl-sulfoxide. It is 
desirable to carry out the reaction in the presence of an acid-acceptor 
such as triethylamine, potassium carbonate and the like at a molar ratio 
of 1.0 to 1.2 moles of the acid-acceptor per mole of the compound of the 
formula (9). The amine (10) can also be used as acid acceptor in which 2 
or more molar excess of this reagent is used. 
Alternatively, compounds according to this invention wherein B is oxygen, 
can also be prepared by the following scheme. 
##STR9## 
In accordance with the foregoing reaction scheme, the alkyl 
2-(2,3,4,5-tetrafluoro)benzoyl acetate (A) can be converted to the anilino 
compound (C) by treatment of the acetate (A) with sodium hydride in 
non-aprotic solvent, preferably tetrahydrofuran and the substituted phenyl 
isothiocyanate (B) and then reacting the intermediate in situ with methyl 
iodide. The reaction can be carried out at room temperature or elevated 
temperature as desired. Treatment of this anilino compound (C) with sodium 
hydride in THF or dimethylformanide at room temperature or elevated 
temperature yields the 1,4-dihydro-4-oxo-quinoline-3-carboxylic acid ester 
(D). Reaction of this ester (D) with dilute acid in aqueous acetronitrile 
or other suitable solvent for a period of time gives the phenol (E). 
Treatment of this alcohol (E) with sodium hydride in non-aprotic solvent 
or other strong base such as sodium hydroxide, or lithium dialkylamides 
such as lithium di-isopropylamide, lithium bistrimethylsilylamide yields 
the phenoxazine derivative (F). Reaction of the phenoxazine (F) with an 
amine (ZH) yields the amino substituted derivative (G). The reaction may 
be conducted at a temperature from 20.degree. C. to 130.degree. C. in the 
presence of a suitable organic polar or non-polar solvent such as 
pyridine, methylene chloride, chloroform, tetrahydrofuran, 
1-methyl-2-pyrrolidinone, dimethylformamide or dimethylsulfoxide. 
Oxidation of compound (G) with metachloroperbenzoic acid or other peracid 
in methylene chloride or other organic solvent or in an aqueous or 
non-aqueous acidic medium yields the sulfoxide (H). Treatment of this 
sulfoxide (H) with N-hydroxyurea in an aprotic or non-aprotic solvent such 
as ethanol, methanol, tertbutyl alcohol, tetrahydrofuran and 
dimethylformamide, in the presence of a base such as DBU, DBN, sodium 
hydride, and potassium t-butoxide gives the 6-(substituted 
amino)-7-fluoro-10,11-dihydro-9-H-isoxazolo[4',5':5,6]pyrido[1,2,3-mn]subs 
tituted phenoxazine-9,10-dione (I). The reaction may be conducted at room 
temperature or suitable elevated temperature. 
Compounds wherein B is sulfur can be prepared by the following reaction 
scheme in which Z and R are as described above, and R.sub.11 is C.sub.1 to 
C.sub.4 alkyl group. 
##STR10## 
In accordance with the above scheme, the substituted benzoic acid (1') can 
be converted to its acid chloride (2') by treatment with thionyl chloride. 
Displacement of the acid chloride (2') with malonic acid half ester in the 
presence of n-butyl lithium yields the beta-ketoester (3'). Treatment of 
the beta-keto ester (3') with sodium hydride in non-aprotic solvent, 
preferably tetrahydrofuran with methyl N-substituted 
iminochlorothioformate (4') at room temperature or suitable elevated 
temperature as desired yields the 1,4-dihydro-4-oxo-quinoline-3-carboxylic 
acid ester (5'). 
Treatment of this ester (5') with dilute acid in aqueous acetonitrile for a 
period of time gives a phenol which is then reacted with sodium hydride to 
give the phenoxazine derivative (6'). 
Oxidation of this derivative (6') with metachlorperbenzoic acid yields the 
sulfoxide (7'). The reaction may be conducted at room temperature or 
elevated temperature in the presence of non-polar solvent such as 
methylene chloride or chloroform. 
Reaction of (7') with sodium hydrosulfide in an aprotic solvent, preferably 
aqueous tetrahydrofuran, at room or elevated temperature yields the 
4-mercapto-derivative (8'). Treatment of (8') with 
hydroxylamine-O-sulfonic acid in the presence of a base, preferably sodium 
bicarbonate in aprotic solvent, preferably aqueous tetrahydrofuran yields 
the 
6,7-difluoro-10,11-dihydro-9H-isothiazolo[4',5':5,6]pyrido[1,2,3-mn]substi 
tuted phenoxazine-9,10-dione derivative (9'). 
Displacement of the 6-halogen of (9') with an amine (10') yields the 
6-substituted amino-isothiazolo-pyrido-phenoxazine (I'). The reaction may 
be conducted at a temperature from 20.degree. C. to 130.degree. C. in the 
presence of a suitable organic polar or non-polar solvent such as 
pyridine, methylene chloride, chloroform, tetra-hydrofuran, 
1-methyl-2-pyrrolidinone, dimethyl formamide or dimethyl-sulfoxide. It is 
desirable to carry out the reaction in the presence of an acid-acceptor 
such as triethylamine, potassium carbonate and the like at a molar ratio 
of 1.0 to 1.2 moles of the acid-acceptor per mole of the compound of the 
formula (9). The amine (10) can also be used as acid acceptor in which 2 
or more molar excess of this reagent is used. 
Alternatively, compounds according to this invention wherein B is sulfur 
can also be prepared by the following scheme using compound (G) described 
before as starting material. 
##STR11## 
In accordance with the above scheme, treatment of the compound (G) with 
sodium hydrosulfide in an aprotic solvent, preferably aqueous 
tetrahydrofuran, at room or elevated temperature yields the 
mercapto-derivative (J). Reaction of compound (J) with 
hydroxylamine-O-sulfonic acid in the presence of a base, preferably sodium 
bicarbonate in an aprotic solvent preferably aqueous tetrahydrofuran 
yields the 6-substituted 
amino-7-fluoro-10,11-dihydro-9H-isothiazolo[4',5':5,6]pyrido[1,2,3-mn]subs 
tituted phenoxazine-9,10-dione (I'). The reaction may be conducted at 
room-temperature or suitable elevated temperature.

The foregoing may be better understood from the following examples, which 
are presented for purposes of illustration and are not intended to limit 
the scope of the inventive concepts. As used in the following examples, 
the references to compounds, such as (1), (2), (3) or (1'), (2'), (3'), 
(A), (B), (C), etc., and to substituents, such as R, R.sub.7, etc., refer 
to the corresponding compounds and substituents in the foregoing reaction 
schemes and in formulae I and I'. Formulae I and I' each represent 
compounds of structure I on page 1 of this specification. 
EXAMPLE 1 
6-(4-methyl-1-piperazinyl)-7-fluoro-10,11-dihydro-9H-isoxazolo[4',5':5,6]py 
rido[1,2,3-mn]phenoxazine-9,10-dione 
(a) A mixture of 1.17 g of 2,4,5-trifluoro-3-acetyloxy-benzoic acid (1) and 
thionyl chloride (10 ml) and 1 drop of dimethylformamide is heated at 
refluxing temperature for 4 hours. The solution is evaporated to dryness 
to give the acid chloride (2). This acid chloride, dissolved in 10 ml of 
tetrahydrofuran (THF) is added slowly to a solution of 1.32 g of 
ethylmalonate monoester in 25 ml of THF solution containing 9.09 ml of 2.2 
molar solution of n-butyl lithium in hexane at -60.degree. C. It is 
allowed to stir at -55.degree. C. to -60.degree. C. for 1 hour. The 
solution is allowed to warm up to room temperature and then acidified with 
20 ml of 1N hydrochloric acid and extracted with ether. The ether extract 
is washed with saturated NaHCO.sub.3 and then water, and dried to yield 
1.29 g of the ketoester (3) (R.sub.11 =C.sub.2 H.sub. 5). 
(b) 800 mg of a 60% sodium hydride-in-oil suspension is slowly added to a 
solution of 2.03 g methyl N-(2-fluorophenyl)iminochlorothioformate (4) 
(R=H) and 4.34 g ketoester (3) (R.sub.11 =C.sub.2 H.sub.5). The mixture is 
then heated at reflux for 24 hours. It is then cooled and evaporated under 
reduced pressure to dryness. The residue is dissolved in methylene 
chloride and washed with saturated sodium chloride solution. Organic layer 
is separated and dried over magnesium sulfate. The product is purified 
through silica gel column yielding the 
1,4-dihydro-4-oxo-quinoline-3-carboxylate (5) (R.sub.11 =C.sub.2 H.sub.5, 
R=H). 
(c) To a solution of 2.75 g of the preceding compound (5) (R.sub.11 
=C.sub.2 H.sub.5, R=H) in 30 ml acetonitrile is added in 10 ml 2N 
hydrochloride acid solution. The mixture is stirred for 24 hours at room 
temperature. The mixture is then evaporated to dryness and redissolved in 
THF. 200 mg of sodium hydride is added. After heating for 24 hours at 
50.degree. C. the reaction mixture is then evaporated under reduced 
pressure to dryness. The residue is dissolved in methylene chloride and 
washed with water. The organic solvent is separated and dried and 
evaporated to dryness. After purification, it yields the phenoxazine 
derivative (6) (R.sub.11 =C.sub.2 H.sub.5, R=H). 
(d) To a solution of 3.90 g of the preceding compound (6) (R.sub.11 
=C.sub.2 H.sub.5, R=H) in 100 ml methylene chloride is added in 2.18 g of 
80% metachloroperbenzoic acid. After stirring at 25.degree. C. for 7 
hours, the solution is diluted with 150 ml of methylene chloride and 
washed with dilute sodium bicarbonate solution. The organic solvent is 
dried over magnesium and evaporated to dryness. 15 ml of ether is added to 
the residue and it crystallizes yielding, after filtration the sulfoxide 
(7) (R.sub.11 =C.sub.2 H.sub.5, R=H). 
(e) 0.4 g of 60% sodium hydride in oil suspension is added slowly to a 
solution of 4.0 g of the preceding compound (7) (R.sub.11 =C.sub.2 
H.sub.5, R=H) and 1.31 g of ethyl acetohydroxamate in 80 ml THF. After 
stirring at room temperature for 24 hours, the mixture is evaporated to 
dryness and the residue is dissolved in methylene chloride (150 ml) and 
washed with water. The organic portion is dried and evaporated to dryness 
and the residue is purified by column chromatography yielding the 
hydroxamate (8) (R.sub.11 =C.sub.2 H.sub.5, R=H). 
(f) To a solution of 2.3 g of the preceding hydroxamate derivative (8) 
(R.sub.11 =C.sub.2 H.sub.5, R=H) in 15 ml THF is added 70% perchloric acid 
(3 ml) with stirring at 0.degree. C. for 10 minutes. The mixture is then 
poured into ice water yielding a solid which is filtered. The solid is 
then dissolved in 60 ml water/THF mixture and 3.2 g sodium bicarbonate in 
30 ml H.sub.2 O is then added. After 5 hours, the mixture is extracted 
with either (25 ml.times.2). The aqueous layer is acidified with dilute 
hydrochloric acid to pH 3 and the precipitate is filtered yielding 
6,7-difluoro-10,11-dihydro-9H-isoxazolo[4',5':5,6]pyrido[1,2,3-mn]phenoxaz 
ine-9,10-dione (9) (R=H). 
(g) To a solution of 1.58 g of the preceding isoxazolo-pyrido-phenoxazine 
derivative (9) (R=H) in 30 ml pyridine is added in 2.5 ml 
N-methylpiperazine. It is then heated under Nitrogen atmosphere at 
60.degree. C. for 24 hours. The mixture is evaporated to dryness and is 
then boiled in ethanol for 5 minutes and the mixture is filtered and 
washed with water yielding the 
6-(4-methyl-1-piperazinyl)-7-fluoro-10,11-dihydro-9H-isoxazolo[4',5':5,6]p 
yrido[1,2,3-mn]phenoxazine-9,10-dione (I) 
##STR12## 
R=H). 
EXAMPLE 2 
6-(1-piperazinyl)-7-fluoro-10,11-dihydro-9H-isoxazolo[4',5':5,6]pyrido[1,2, 
3-mn]phenoxazine-9,10-dione 
(a) The procedure of Example 1 can be repeated, replacing the 
N-methylpiperazinyl in Example 1(g) with piperazine, to obtain 
6-(1-piperazinyl)-7-fluoro-10,11-dihydro-9H-isoxazolo[4',5':5,6]pyrido[1,2 
,3-mn]phenoxazine-9,10-dione (I) 
##STR13## 
R=H). 
(b) Alternatively, the title compound is prepared as follows: To a solution 
of 2.67 g of ethyl 2,3,4,5-tetrafluorobenzoyl acetate (A) (R.sub.11 
=C.sub.2 H.sub.5) in 30 ml of tetrahydrofuran (THF) is added 1.93 g of the 
isothiocyanate (B) (R=H). The solution is cooled with an ice bath, and 
0.41 g of a 60% sodium hydride in-oil suspension is then added into the 
mixture. After 18 hours, 0.65 ml of methyl iodide is added. The reaction 
is allowed to react at room temperature for 16 hours. 1 ml of acetic acid 
is added into the mixture and the solution is removed by evaporation under 
reduced pressure. The residue is dissolved in methylene chloride (300 ml) 
and washed with saturated sodium chloride solution. The organic layer is 
dried and purified through a silica gel column to give 3.7 g of compound 
(C) (R=H, R.sub.11 =C.sub.2 H.sub.5). 
(c) 200 mg of 60% sodium hydride-in-oil suspension is added slowly to 2.7 g 
of the preceding compound (C) (R=H, R.sub.11 =C.sub.2 H.sub.5) in 40 ml 
THF in 0.degree. C. After the addition, the mixture is heated at 
65.degree. C. for 16 hours. After cooling, 0.5 ml of acetic acid is added 
and the solvent is removed by distillation under reduced pressure. The 
residue is dissolved in 250 ml methylene chloride and washed with 
saturated sodium chloride soltuion. The organic portion is dried and 
evaporated to dryness. A 50% mixture of hexane and ether is added into the 
residue and filtered, yielding the 1,4-dihydro-4-oxoquinoline-3-carboxylic 
acid ester (D) (R=H, R.sub.11 =C.sub.2 H.sub.5). 
(d) To a solution of 4.5 g of (D) R=H, R.sub.11 =C.sub.2 H.sub.5) in 100 ml 
acetonitrile is added 10 ml 3N hydrochloric acid. The solution is heated 
at 50.degree. C. for 3 hours. The solution is then removed by evporation 
under reduced pressure. Ether (50 ml) is added and filtered yielding 3.8 g 
of the phenol (E) (R=H, R.sub.11 =C.sub.2 H.sub.5). 
(e) 200 mg of 60% sodium hydride-in-oil suspension is added to a cold 
solution of 2.0 g of (E) (R=H, R.sub.11 =C.sub.2 H.sub.5) in dry 
dimethylformamide. After the addition, the solution is heated at 
100.degree. C. under nitrogen atmosphere for 16 hours. It is then cooled 
and 0.5 ml of acetic acid is added. The solvent is then removed under 
reduced pressure. The residue is dissolved in 400 ml methylene chloride 
and washed with saturated sodium chloride solution. It is then dired and 
evaporated to dryness under reduced pessure. Ether (100 ml) is added and 
filtered yielding the phenoxazine derivative (F) (R=H, R.sub.11 =C.sub.2 
H.sub.5). 
(f) To a solution of 3.8 g of (F) (R=H, R.sub.11 =C.sub.2 H.sub.5) in 
pyridine (50 ml) is added 6 g of N-carbobenzoxypiperazine. The mixture is 
heated at 110.degree. C. for 2 days. The solvent is removed by evaporation 
under reduced pressure. Ether is added in and filtered. The residue is 
then washed with water and then ether giving the residue (G) (R=H, 
R.sub.11 =C.sub.2 H.sub.5), Z=4-carbobenzoxypiperazin-1-yl). 
(g) To a solution of 1.47 g of (G) (R=H, R.sub.11 =C.sub.2 H.sub.5) in 100 
ml methylene chloride at room temperature is added 540 mg 
metachloroperbenzoic acid. After 1 day, 200 ml of methylene chloride is 
added and the solution is washed with cold dilute sodium bicarbonate 
solution. The organic layer is dried and evaporated to dryness. 
Crystallization from ethanol yields the sulfoxide (H) (R=H, R.sub.11 
=C.sub.2 H.sub.5). 
(h) To a solution of 1.5 g of the sulfoxide (H) (R=H, R.sub.11 =C.sub.2 
H.sub.5) in 50 ml methanol is added 190 mg hydroxyurea and 380 mg DBU 
(1,8-diazabicyclo[5.4.0]undec-7-ene). After 1 day, the solution is removed 
and 2 ml of acetic acid and water (100 ml) are added. The mixture is 
filtered yielding (I) 
##STR14## 
R=H). 
(i) 1 g of the preceding compound (I) is dissolved in 5 ml of hydrogen 
bromide in glacial acetic acid. After 5 minutes, ether 150 ml is added and 
filtered and washed with ether again. It gives the title compound as the 
hydrobromide salt in good yield 
EXAMPLE 3 
6-(3-formamido-1-pyrrolidinyl)-7-fluoro-10,11-dihydro-9H-isoxazolo[4',5':5, 
6]pyrido[1,2,3-mn]phenoxazine-9,10-dione 
In the described fashion as Example 2(b)-2(h), replacing the 
N-carboxypiperazine in Example 2(f) with 3-formamido-1-pyrrolidine, one 
can obtain 
6-(3-formamido-1-pyrrolidinyl)-7-fluoro-10,11-dihydro-9H-isoxazolo[4',5':5 
,6]pyrido[1,2,3-mn]phenoxazine-9,10-dione (I) 
##STR15## 
R=H). 
EXAMPLE 4 
6-(3-amino-1-pyrrolidinyl)-7-fluoro-10,11-dihydro-9H-isoxazolo[4',5':5,6]py 
rido[1,2,3-mn]phenoxazine-9,10-dione 
The product of Example 3, I 
##STR16## 
R=H) can be hydrolyzed by the use of dilute hydrochloric acid in 
acetonitrile to yield 
6-(3-amino-1-pyrrolidinyl)-7-fluoro-10,11-dihydro-9H-isoxazolo[4',5':5,6]p 
yrido[1,2,3-mn]phenoxazine-9,10-dione hydrochloride salt (I) 
##STR17## 
R=H). 
EXAMPLE 5 
3,7-difluoro-6-(4-methyl-1-piperazinyl)-10,11-dihydro-9H-isoxazolo[4',5':5, 
6]pyrido[1,2,3-mn]phenoxazine-9,10-dione 
(a) In the described fashion in Example 1(b) replacing methyl 
N-(2-fluorophenyl)iminochlorothioformate (4) (R=H) with methyl 
N-(2,4-difluorophenyl)iminochlorothioformate (4) (R=4-fluoro) one can 
obtain the 1,4-dihydro-4-oxo-quinoline-3-carboxylate (5) (R.sub.11 
=C.sub.2 H.sub.5, R=p--F). 
(b) By following Example 1(c-f), the preceding compound (5) (R.sub.11 
=C.sub.2 H.sub.5, R=p--F) can yield the 
3,6,7-trifluoro-10,11-dihydro-9H-isoxazolo[4',5':5,6]pyrido[1,2,3-mn]pheno 
xazine-9,10-dione (9) (R=3--F). 
(c) In the described fashion as Example 1(g) displacing the 6-fluoro with 
N-methylpiperazine, the preceding compound (9) can yield 
3,7-difluoro-6-(4-methyl-1-piperazinyl)-10,11-dihydro-9H-isoxazolo[4',5':5 
,6]pyrido[1,2,3-mn]phenoxazine-9,10-dione (I) 
##STR18## 
R=3--F). 
EXAMPLE 6 
By following the example 5(a-c), replacing the N-methylpiperazine in 
Example 5(c) with various amines such as piperazine, 
3-formamidopyrrolidine, piperidine, pyrrolidine, morpholine, 
thiomorpholine, homopiperazine, N,N-dimethylhydrazine, 2-methylpiperazine, 
2-phenylpiperazine, 2,6-dimethylpiperazine, 3-amino-4-methylpyrrolidine, 
3-aminomethylpyrroldine, 3-aminomethyl-4-chloropyrrolidine, one can obtain 
the following compounds. 
(a) 
3,7-difluoro-6(1-piperazinyl)-10,11-dihydro-9H-isoxazolo[4',5':5,6]pyrido[ 
1,2,3-mn]phenoxazine-9,10-dione (I) 
##STR19## 
R=3--F). 
(b) 
3,7-difluoro-6-(3-formamido-1-pyrrolidinyl)-10,11-dihydro-9H-isoxazolo[4', 
5':5,6]pyrido[1,2,3-mn]phenoxazine-9,10-dione (I) 
##STR20## 
R=3-F). 
(c) 
3,7-difluoro-6-(1-piperidinyl)-10,11-dihydro-9H-isoxazolo[4',5':5,6]pyrido 
[1,2,3-mn]phenoxazine-9,10-dione (I) 
##STR21## 
R=3--F). 
(d) 
3,7-difluoro-6-(1-pyrrolidinyl)-10,11-dihydro-9H-isoxazolo[4',5':5,6]pyrid 
o[1,2,3-mn]phenoxazine-9,10-dione (I) 
##STR22## 
R=3--F). 
(e) 
3,7-difluoro-6-(1-morpholinyl)-10,11-dihydro-9H-isoxazolo[4',5':5,6]pyrido 
[1,2,3-mn]phenoxazine-9,10-dione (I) 
##STR23## 
R=3--F). 
(f) 
3,7-difluoro-6-(1-thiomorpholinyl)-10,11-dihydro-9H-isoxazolo[4',5':5,6]py 
rido[1,2,3-mn]phenoxazine-9,10-dione (I) 
##STR24## 
R=3--F). 
(g) 
3,7-difluoro-6-(1-homopiperazinyl)-10,11-dihydro-9H-isoxazolo[4',5':5,6]py 
rido[1,2,3-mn]phenoxazine-9,10-dione (I) 
##STR25## 
R=3--F). 
(h) 
3,7-difluoro-6-(1-N,N-dimethylhydrazyl)-10,11-dihydro-9H-isoxazolo[4',5':5 
,6]pyrido[1,2,3-mn]phenoxazine-9,10-dione (I) (Z=NH--N(CH.sub.3).sub.2, 
R=3--F). 
(i) 
3,7-difluoro-6-(3-methyl-1,-piperazinyl)-10,11-dihydro-9H-isoxazolo[4',5': 
5,6]pyrido[1,2,3-mn]phenoxazine-9,10-dione (I) 
##STR26## 
(j) 
3,7-difluoro-6-(3-phenyl-1-piperazinyl)-10,11-dihydro-9H-isoxazolo[4',5':5 
,6]pyrido[1,2,3-mn]phenoxazine-9,10-dione (I) 
##STR27## 
R=3--F). 
(k) 
3,7-difluoro-6-(3,4-dimethyl-1-piperazinyl)-10,11-dihydro-9H-isoxazolo[4', 
5':5,6]pyrido[1,2,3-mn]phenoxazine-9,10-dione (I) 
##STR28## 
R=3--F). 
(l) 
3,7-difluoro-6-(3-amino-4-methyl-1-pyrrolidinyl)-10,11-dihydro-9H-isoxazol 
o[4',5':5,6]pyrido[1,2,3-mn]phenoxazine-9,10-dione (I) 
##STR29## 
R=3--F). 
(m) 
3,7-difluoro-6-(3-aminomethyl-1-pyrrolidinyl)-10,11-dihydro-9H-isoxazolo[4 
',5':5,6]pyrido[1,2,3-mn]phenoxazine-9,10-dione (I) 
##STR30## 
R=3--F). 
(n) 
3,7-difluoro-6-(3-aminomethyl-4-chloro-1-pyrrolidinyl)-10,11-dihydro-9H-is 
oxazolo[4',5':5,6]pyrido[1,2,3-mn]phenoxazine-9,10-dione (I) 
##STR31## 
R=3--F). 
EXAMPLE 7 
3,7-difluoro-6-(3-amino-1-pyrrolidinyl)-10,11-difluoro-9H-isoxazolo-[4',5': 
5,6]pyrido[1,2,3-mn]phenoxazine-9,10-dione 
By following the procedure as Example (4), the product of Example 6(b) can 
be hydrolyzed to yield 
3,7-difluoro-6-(3-amino-1-pyrrolidinyl)-10,11-dihydro-9H-isoxazolo[4',5':5 
,6]pyrido[1,2,3-mn]phenoxazine-9,10-dione hydrochloride salt (I) 
##STR32## 
R=3--F). 
EXAMPLE 8 
1,3,7-trifluoro-6-(4-methyl-1-piperazinyl)-10,11-dihydro-9H-isoxazolo[4',5' 
:5,6]pyrido[1,2,3-mn]phenoxazine-9,10-dione 
(a) In the described fashion as Example 1(b), replacing methyl 
N-(2-fluorophenyl)iminochlorothioformate (4) (R=H) with methyl 
N-(2,4,5-trifluorophenyl)iminochlorothioformate (4) (R=4-fluoro) one can 
obtain the 1,4-dihydro-4-oxo-quinoline-3-carboxylate (5) (R.sub.11 
=C.sub.2 H.sub.5, R=o,p--di F). 
(b) By following Example 1(c-f), the preceding compound (5) (R.sub.11 
=C.sub.2 H.sub.5, R=o,p--di F) can yield the 
1,3,6,7-tetrafluoro-10,11-dihydro-9H-isoxazolo[4',5'=5,6]pyrido[1,2,3-mn]p 
henoxazine-9,10-dione (9) (R=1,3--di F). 
(c) In the described fashion as Example 1(g) displacing the 6-fluoro with 
N-methylpiperazine, the preceding compound (9) can yield 
1,3,7-trifluoro-6-(4-methyl-1-piperazinyl)-10,11-dihydro-9H-isoxazolo[4',5 
':5,6]pyrido[1,2,3-mn]phenoxazine-9,10-dione (I) 
##STR33## 
R=1,3--di F). 
EXAMPLE 9 
By following the Exanple (8)(a-c), replacing the N-methylpiperazine in 
Example (8)(c) with various amines such as piperazine, 
3-formamidopyrrolidine, 3-((ethylamino)methyl)-pyrrolidine, one can obtain 
the following compounds. 
(a) 
1,3,7-trifluoro-6-(1-piperazinyl)-10,11-dihydro-9H-isoxazolo[4',5'-5,6]pyr 
ido[1,2,3-mn]phenoxazine-9,10-dione (I) 
##STR34## 
R=1,3--di F). 
(b) 
1,3,7-6-(3-formamido-1-pyrrolidinyl)-10,11-dihydro-9H-isoxazolo[4',5':5,6] 
pyrido[1,2,3-mn]phenoxazine-9,10-dione (I) 
##STR35## 
R=1,3--di F). 
(c) 
1,3,7-trifluoro-6-(3-(ethylamino)methyl-1-pyrrolidinyl)-10,11-dihydro-9H-i 
soxazolo[4',5'-5,6]pyrido[1,2,3-mn]phenoxazine-9,10-dione (I) 
##STR36## 
R=1,3--di F). 
EXAMPLE 10 
1,3,7-trifluoro-6-(3-amino-1-pyrrolidinyl)-10,11-dihydro-9H-isoxazolo[4,',5 
':5,6]pyrido[1,2,3-mn]phenoxazine-9,10-dione 
By following the procedure as Example (4), the product of Example 9(b) can 
be hydrolyzed to yield 
1,3,7-trifluoro-6-(3-amino-1-pyrrolidinyl)-10,11-dihydro-9H-isoxazolo[4',5 
':5,6]pyrido[1,2,3-mn]phenoxazine-9,10-dione hydrochloride salt (I) 
##STR37## 
R=1,3--di F). 
EXAMPLE 11 
In the described fashion as Example 1(b). replacing methyl 
N-(2-fluorophenyl)iminochlorothioformate (4) (R=H) with an appropriate 
N-substituted iminochloroformate (4) such as R equals to 
4,5-methylenedioxy, 4-hydroxy, 4-methoxy, 4-methyl, one can obtain the 
following 1,4-dihydro-4-oxo-quinoline-3-carboxylate (5) 
(a) Compound (5) R=m,p-methylenedioxy 
(b) Compound (5) R=4-hydroxy 
(c) Compound (5) R=4-methoxy 
(d) Compound (5) R=4-methyl 
EXAMPLE 12 
By following Example 1(c-f), the preceding compound (5)(a), (b), (c) and 
(d) can yield the following compounds: 
(a) 
2,3-methylenedioxy-6,7-difluoro-10,11-dihydro-9H-isoxazolo[4',5':5,6]pyrid 
o[1,2,3-mn]phenoxazine-9,10-dione (9) (R=2,3-methylenedioxy). 
(b) 
3-hydroxy-6,7-difluoro-10,11-dihydro-9H-isoxazolo[4',5':5,6]pyrido[1,2,3-m 
n]phenoxazine-9,10-dione (9) (R=3--OH). 
(c) 
3-methoxy-6,7-difluoro-10,11-dihydro-9H-isoxazolo[4',5':5,6]pyrido[1,2,3-m 
n]phenoxazine-9,10-dione (9) R=3--OCH.sub.3). 
(d) 
3-methyl-6,7-difluoro-10,11-dihydro-9H-isoxazolo[4',5':5,6]pyrido-[1,2,3-m 
n]phenoxazine-9,10-dione (9) (R=3--CH.sub.3). 
EXAMPLE 13 
In the described fashion as Example 1(g), using compounds in Example 
11(a-d) instead of compound (9) (R=H) and replacing N-methylpiperazine 
with an appropriate amine such as 3-methylaminopyrrolidine, 
3-hydroxypyrrolidine, 3-hydroxymethylpyrrolidine, M-methylhydrazine, 
1,2-diaminoethane, ethanolamine, ethylamine and 
2-p-fluorophenylpiperazine, one can obtain the following compounds. 
(a) 
2,3-methylenedioxy-6-(3-methylamino-1-pyrrolidinyl)-7-fluoro-10,11-dihydro 
-9H-isoxazolo[4',5':5,6]pyrido[1,2,3-mn]phenoxazine-9,10-dione (I) 
##STR38## 
R=2,3-methylenedioxy.) 
(b) 
3-hydroxy-6-(3-hydroxy-1-pyrrolidinyl)-7-fluoro-10,11-dihydro-9H-isoxazolo 
[4',5':5,6]pyrido[1,2,3-mn]phenoxazine-9,10-dione (I) 
##STR39## 
R=3--OH). 
(c) 
3-methoxy-6-(3-hydroxymethyl-1-pyrrolidinyl)-7-fluoro-10,11-dihydro-9H-iso 
xazolo[4',5':5,6]pyrido[1,2,3-mn]phenoxazine-9,10-dione (I) 
##STR40## 
R=3--OCH.sub.3). 
(d) 
3-methyl-6-(2-methyl-1-hydrazyl)-7-fluoro-10,11-dihydro-9H-isoxazolo[4',5' 
:5,6]pyrido[1,2,3-mn]phenoxazine-9,10-dione (I) (Z=NHNHCH.sub.3, 
R=3-CH.sub.3). 
(e) 
3-methyl-6-aminoethylamino-7-fluoro-10,11-dihydro-9H-isoxazolo[4',5':5,6]p 
yrido[1,2,3-mn]phenoxazine-9,10-dione (I) (Z=NHC.sub.2 H.sub.4 NH.sub.2, 
R=3--CH.sub.3). 
(f) 
3-methyl-6-hydroxyethylamino-7-fluoro-10,11-dihydro-9H-isoxazolo[4',5':5,6 
]pyrido[1,2,3-mn]phenoxazine-9,10-dione (I) (Z=NHC.sub.2 H.sub.4 OH, 
R=3--CH.sub.3). 
(g) 
3-methyl-6-ethylamino-7-fluoro-10,11-dihydro-9H-isoxazolo[4',5':5,6]pyrido 
[1,2,3-mn]phenoxazine-9,10-dione (I) (Z=NHC.sub.2 H.sub.5, R=3--CH.sub.3). 
(h) 
3-methyl-6-(3-p-fluorophenyl-1-piperazinyl)-7-fluoro-10,11-dihydro-9H-isox 
azolo[4',5':5,6]pyrido[1,2,3-mn]phenoxazine-9,10-dione (I) 
##STR41## 
R=3--CH.sub.3). 
EXAMPLE 14 
6-(3-N-ethylaminomethylpyrrolidin-1-yl)-7-fluoro-10,11-dihydro-9H-isoxazolo 
[4',5':5,6]pyrido[1,2,3-mn]phenoxazine-9,10-dione 
In the described fashion as Example 2(b)-2(h), replacing the 
N-carbobenzoxypiperazine in Example 2(f) with 3-(N-carbobenzoxy-N-ethyl 
aminomethyl)pyrrolidine, one can obtain 
6-(3-N-ethylaminomethylpyrrolidin-1-yl)-7-fluoro-10,11-dihydro-9H-isoxazol 
o[4',5':5,6]pyrido[1,2,3-mn]phenoxazine-9,10-dione (I) (R=H, 
##STR42## 
EXAMPLE 15 
6-(4-methyl-1-piperazinyl)-7-fluoro-10,11-dihydro-9H-isothiazolo[4',5':5,6] 
pyrido[1,2,3-mn]phenoxazine-9,10-dione 
(a) A mixture of 1.17 g of 2,4,5-trifluoro-3-acetyloxy-benzoic acid (1') 
and thionyl chloride (10 ml) and 1 drop of dimethylformamide is heated at 
refluxing temperature for 4 hours. The solution is evaporated to dryness 
to give the acid chloride (2'). This acid chloride, dissolved in 10 ml of 
tetrahydrofuran (THF) is added slowly to a solution of 1.32 g of 
ethylmalonate monoester in 25 ml of THF solution containing 9.09 ml of 2.2 
molar solution of n-butyl lithium in hexane at -60.degree. C. It is 
allowed to stir at -55.degree. C. to -60.degree. C. for 1 hour. The 
solution is allowed to warm up to room temperature and then acidified with 
20 ml of 1N hydrochloric acid and extracted with ether. The ether extract 
is washed with saturated NaHCO.sub.3 and then water, and dried to yield 
1.29 g of the ketoester (3) (R.sub.11 =C.sub.2 H.sub.5). 
(b) 800 mg of a 60% sodium hydride-in-oil suspension is slowly added to a 
solution of 2.03 g methyl N-(2-fluorophenyl)iminochlorothioformate (4') 
(R=H) and 4.34 g ketoester (3') (R.sub.11 =C.sub.2 H.sub.5). The mixture 
is then heated at reflux for 24 hours. It is then cooled and evaporated 
under reduced pressure to dryness. The residue is dissolved in methylene 
chloride and washed with saturated sodium chloride solution. Organic layer 
is separated and dried over magnesium sulfate. The product is purified 
through silica gel column yielding the 
1,4-dihydro-4-oxo-quinoline-3-carboxylate (5') (R.sub.11 =C.sub.2 H.sub.5, 
R=H). 
(c) To a solution of 2.75 g of the preceding compound (5') (R.sub.11 
=C.sub.2 H.sub.5, R=H) in 30 ml acetonitrile is added in 10 ml 2N 
hydrochloric acid solution. The mixture is stirred for 24 hours at room 
temperature. The mixture is then evaporated to dryness and redissolved in 
THF. 200 mg of sodium hydride is added. After heating for 24 hours at 
50.degree. C. the reaction mixture is then evaporated under reduced 
pressure to dryness. The residue is dissolved in methylene chloride and 
washed with water. The organic solvent is separated and dried and 
evaporated to dryness. After purification, it yields the phenoxazine 
derivative (6') (R.sub.11 =C.sub.2 H.sub.5, R=H). 
(d) To a solution of 3.90 g of the preceding compound (6') (R.sub.11 
=C.sub.2 H.sub.5, R=H) in 100 ml methylene chloride is added in 2.18 g of 
80% metachloroperbenzoic acid. After stirring at 25.degree. C. for 2 days, 
the solution is diluted with 150 ml of methylene chloride and washed with 
dilute sodium bicarbonate solution. The organic solvent is dried over 
magnesium and evaporated to dryness. 15 ml of ether is added to the 
residue and it crystallizes yielding, after filtration the sulfoxide (7') 
(R.sub.11 =C.sub.2 H.sub.5, R=H). 
(e) 2.18 ml of 0.92N sodium hydrosulfide solution is added to 820 mg of the 
preceding sulfoxide (7') (R.sub.11 =C.sub.2 H.sub.5, R=H) in 10 ml THF. 
After the solution is stirred at room temperature, the solution is diluted 
with 30 ml water containing 252 mg NaHCO.sub.3 and extracted with ether 
twice. The aqueous solution is cooled to 5.degree. C. and acidified with 6 
ml 1N hydrochloric acid. The precipitate is filtered and dried yielding 
the mercapto-phenoxazine derivative (8') (R.sub.11 =C.sub.2 H.sub.5, R=H). 
(f) To a solution of 375 mg of the preceding compound (8') (R.sub.11 
=C.sub.2 H.sub.5, R=H) in 8 ml of THF and 20 ml of water solution 
containing 1.8 g sodium bicarbonate is added in 450 mg hydroxylamine --O-- 
sulfonic acid. After stirring for 4 hours, the mixture is diluted with 
water (20 ml) and is extracted with ether (25 ml.times.2). The aqueous 
portion is acidified to pH 3 and the precipitate is filtered yielding 
6,7-difluoro-10,11-9H-isothioazolo[4',5':5,6]pyrido[1,2,3-mn]phenoxazine-9 
,10-dione (9') (R=H). 
(g) To a solution of 1.67 g of the preceding isothiazolo-pyrido-phenoxazine 
derivative (9') (R=H) in 30 ml pyridine is added in 2.5 ml 
N-methylpiperazine. It is then heated under Nitrogen atmosphere at 
60.degree. C. for 24 hours. The mixture is evaporated to dryness and is 
then boiled in ethanol for 5 minutes and the mixture is filtered and 
washed with water yielding the 
6-(4-methyl-1-piperazinyl)-7-fluoro-10,11-dihydro-9H-isothiazo[4',5':5,6]p 
yrido[1,2,3-mn]phenoxazine-9,10-dione (I') 
##STR43## 
R=H). 
EXAMPLE 16 
6(1-piperazinyl)-7-fluoro-10,11-dihydro-9H-isothiazolo[4',5':5,6]pyrido[1,2 
,3-mn]phenoxazine-9,10-dione 
(a) The procedure of Example 15 can be repeated, replacing the 
N-methylpiperazinyl in Example 15(g) with piperazine, to obtain 
6-(1-piperazinyl)-7-fluoro-10,11-dihydro-9H-isothiazolo[4',5':5,6]pyrido[1 
,2,3-mn]phenoxazine-9,10-dione (I') 
##STR44## 
R=H). 
(b) Alternatively, the title compound is prepared as follows: To a solution 
of 2.94 g of (G) (R=H, R.sub.11 =C.sub.2 H.sub.5), product example 2(f) in 
30 ml THF is added 850 mg of sodium hydrosulfide in 2 ml of water. The 
mixture is stirred at 35.degree. C. for 10 hours. The solvent is removed 
by reduced pressure and the residue is dissolved in water (200 ml). Acetic 
acid is added until the pH of the solution is 6. The precipitate is 
filtered and washed with water and ether yielding (J) in good yield (R=H, 
R.sub.11 =C.sub.2 H.sub.5). 
(c) To a solution of 1.15 g (J) (R=H, R.sub.11 =C.sub.2 H.sub.5) in 25 ml 
THF and 15 ml water solution containing 1 g of sodium bicarbonate is added 
800 mg hydroxylamine-O-sulfonic acid. After stirring for 1 day, the 
precipitate is filtered yielding (I) 
##STR45## 
R=H). 
(d) 1 g of the preceding compound is dissolved in 5 ml of hydrogen bromide 
in glacial acetic acid. After 5 minutes, ether (150 ml) is added and the 
residue is filtered and washed with ether yielding the title compound as 
the hydrobromide salt in good yield. 
EXAMPLE 17 
6-(3-formamido-1-pyrrolidinyl)-7-fluoro-10,11-dihydro-9H-isothiazolo[4', 
5':5,6]pyrido[1,2,3-mn]phenoxazine-9,10-dione 
In the described fashion as Example 15, replacing the N-methylpiperazine in 
Example 15(g) with 3-formamido-pyrrolidine, one can obtain 
6-(3-formamido-1-pyrrolidinyl)-7-fluoro-10,11-dihydro-9H-isothiazolo[4',5' 
:5,6]pyrido[1,2,3-mn]phenoxazine-9,10-dione (I') 
##STR46## 
R=H). 
EXAMPLE 18 
6-(3-amino-1-pyrrolidinyl)-7-fluoro-10,11-dihydro-9H-isothiazolo[4',5':5,6] 
pyrido[1,2,3-mn]phenoxazine-9,10-dione 
The product of Example 17, I 
##STR47## 
R=H) can be hydrolyzed by the use of dilute hydrochloric acid in 
acetonitrile to yield 
6-(3-amino-1-pyrrolidinyl)-7-fluoro-10,11-dihydro-9H-isothiazolo[4',5':5,6 
]pyrido[1,2,3-mn]phenoxazine-9,10-dione hydrochloride salt (I') 
##STR48## 
R=H). 
EXAMPLE 19 
3,7-difluoro-6-(4-methyl-1-piperazinyl)-10,11-dihydro-9H-isothiazolo[4',5': 
5,6]pyrido[1,2,3-mn]phenoxazine-9,10-dione 
(a) In the described fashion in Example 15(b) replacing methyl 
N-(2-fluorophenyl)iminochlorothioformate (4') (R=H) with methyl 
N-(2,4-difluorophenyl)iminochlorothioformate (4') (R=4-fluoro) one can 
obtain the 1,4-dihydro-4-oxo-quinoline-3-carboxylate (5') (R.sub.11 
=C.sub.2 H.sub.5, R=p--F). 
(b) By following Example 15(c-f), the preceding compound (5') (R.sub.11 
=C.sub.2 H.sub.5, R=p--F) can yield the 3,6,7-trifluoro-10, 
11-dihydro-9H-isothiazolo[4',5':5,6]pyrido[1,2,3-mn]phenoxazine-9,10-dione 
(9') (R=3--F). 
(c) In the described fashion as Example 15(g) displacing the 6-fluoro with 
N-methylpiperazine, the preceding compound (9') can yield 
3,7-difluoro-6-(4-methyl-1-piperazinyl)-10,11-dihydro-9H-isothiazolo[4',5' 
:5,6]pyrido[1,2,3-mn]phenoxazine-9,10-dione (I') 
##STR49## 
R=3--F). 
EXAMPLE 20 
By following the example 19(a-c), replacing the N-methylpiperazine in 
Example 19(c) with various amines such as piperazine, 
3-formamidopyrrolidine, piperidine, pyrrolidine, morpholine, 
thiomorpholine, homopiperazine, N,N-dimethylhydrazine, 2-methylpiperazine, 
2-phenylpiperazine, 2,6-dimethylpiperazine, 3-amino-4-methylpyrrolidinyl, 
3-aminomethylpyrrolidine, 3-aminomethyl-4-chloro-1-pyrrolidine one can 
obtain the following compounds. 
(a) 
3,7-difluoro-6(1-piperazinyl)-10,11-dihydro-9H-isothiazolo[4',5':5,6]pyrid 
o[1,2,3-mn]phenoxazine-9,10-dione (I') 
##STR50## 
R=3--F). 
(b) 
3,7-difluoro-6-(3-formamido-1-pyrrolidinyl)-10,11-dihydro-9H-isothiazolo[4 
',5':5,6]pyrido[1,2,3-mn]phenoxazine-9,10-dione (I') 
##STR51## 
R=3--F). 
(c) 
3,7-difluoro-6-(1-piperidinyl)-10,11-dihydro-9H-isothiazolo[4',5':5,6]pyri 
do[1,2,3-mn]phenoxazine-9,10-dione (I') 
##STR52## 
R=3--F). 
(d) 
3,7difluoro-6(1-pyrrolidinyl)-10,11-dihydro-9H-isothiazolo[4',5':5,6]pyrid 
o[1,2,3-mn]phenoxazine-9,10dione (I') 
##STR53## 
R=3--F). 
(e) 
3,7-difluoro-6-(1-morpholinyl)-10,11-dihydro-9H-isothiazolo[4',5':5,6]pyri 
do[1,2,3-mn]phenoxazine-9,10-dione (I') 
##STR54## 
R=3--F). 
(f) 
3,7-difluoro-6-(1-thiomorpholinyl)-10,11-dihydro-9H-isothiazolo[4',5':5,6] 
pyrido[1,2,3-mn]phenoxazine-9,10-dione (I') 
##STR55## 
R=3--F). 
(g) 
3,7-difluoro-6-(1-homopiperazinyl)-10,11-dihydro-9H-isothiazolo[4':5'5,6]p 
yrido[1,2,3-mn]phenoxazine-9,10dione (I') 
##STR56## 
R=3--F). 
(h) 
3,7-difluoro-6-(1-N,N-dimethylhydrazyl)-10,11-dihydro-9H-isothiazolo[4',5' 
:5,6]pyrido[1,2,3-mn]phenoxazine-9,10-dione (I') (Z=NH--N(CH.sub.3).sub.2, 
R=3--F). 
(i) 
3,7-difluoro-6-(3-methyl-1-piperazinyl)-10,11-dihydro-9H-isothiazolo[4',5' 
:5,6]pyrido[1,2,3-mn]phenoxazine-9,10-dione (I') 
##STR57## 
R=3--F). 
(j) 
3,7-difluoro-6-(3-phenyl-1-piperazinyl)-10,11-dihydro-9H-isothiazolo[4',5' 
:5,6]pyrido[1,2,3-mn]phenoxazine-9,10-dione (I') 
##STR58## 
R=3--F). 
(k) 
3,7-difluoro-6-(3,5-dimethyl-1-piperazinyl)-10,11-dihydro-9H-isothiazolo[4 
',5':5,6]pyrido[1,2,3-mn]phenoxazine-9,10-dione (I') 
##STR59## 
R=3--F). 
(l) 
3,7-difluoro-6-(3-amino-4-methyl-1-pyrrolidinyl)-10,11-dihydro-9H-isothiaz 
olo[4',5':5,6]pyrido[1,2,3-mn]phenoxazine-9,10-dione (I') 
##STR60## 
R=3--F). 
(m) 
3,7-difluoro-6-(3-aminomethyl-1-pyrrolidinyl)-10,11-dihydro-9H-isothiazolo 
[4',5':5,6]pyrido[1,2,3-mn]phenoxazine-9,10-dione (I') 
##STR61## 
R=3--F). 
(n) 
3,7-difluoro-6-(3-aminomethyl-4-chloro-1-pyrrolidinyl)-10,11-dihydro-9H-is 
othiazolo[4',5':5,6]pyrido[1,2,3-mn]phenoxazine-9,10-dione (I') 
##STR62## 
R=3--F). 
EXAMPLE 21 
3,7-difluoro-6-(3-amino-1-pyrrolidinyl)-10,11-difluoro-9H-isothiazolo-[4',5 
':5,6]pyrido[1,2,3-mn]phenoxazine-9,10-dione 
By following the procedure as Example (18), the product of Example 20(b) 
can be hydrolyzed to yield 
3,7-difluoro-6-(3-amino-1-pyrrolidinyl)-10,11-dihydro-9H-isothiazolo[4',5' 
:5,6]pyrido[1,2,3-mn]phenoxazine-9,10-dione hydrochloride salt (I') 
##STR63## 
R=3--F). 
EXAMPLE 22 
1,3,7-trifluoro-6-(4-methyl-1-piperazinyl)-10,11-dihydro-9H-isothiazolo[4', 
5':5,6]pyrido[1,2,3-mn]phenoxazine-9,10-dione 
(a) In the described fashion as Example 15(b), replacing methyl 
N-(2-fluorophenyl)iminochlorothioformate (4') (R=H) with methyl 
N-(2,4,5-trifluorophenyl)iminochlorothioformate (4') (R=4--fluoro) one can 
obtain the 1,4-dihydro-4-oxo-quinoline-3-carboxylate (5') (R.sub.11 
=C.sub.2 H.sub.5, R=o,p--di F). 
(b) By following Example 15(c-f), the preceding compound (5') (R.sub.11 
=C.sub.2 H.sub.5, R=o,p--di F) can yield the 
1,3,6,7-tetrafluoro-10,11-dihydro-9H-isothiazolo[4',5'-5,6]pyrido[1,2,3-mn 
]phenoxazine-9,10-dione (9') (R=1,3--di F). 
(c) In the described fashion as Example 15(g) displacing the 6-fluoro with 
N-methylpiperazine, the preceding compound (9') can yield 
1,3,7-trifluoro-6-(4-methyl-1-piperazinyl)-10,11-dihydro-9H-isothiazolo[4' 
,5'-5,6]pyrido[1,2,3-mn]phenoxazine-9,10-dione (I') 
##STR64## 
R=1,3--di F). 
EXAMPLE 23 
By following the Example 22(a-c), replacing the N-methylpiperazine in 
Example 22(c) with various amines such as piperazine, 
3-formamidopyrrolidine, 3-((ethylamino)methyl)-pyrrolidine, one can obtain 
the following compounds. 
(a) 
1,3,7-trifluoro-6-(1-piperazinyl)-10,11dihydro-9H-isothiazolo[4',5'-5,6]py 
rido[1,2,3-mn]phenoxazine-9,10-dione (I') 
##STR65## 
R=1,3--di F). 
(b) 
1,3,7-6-(3-formamido-1-pyrrolidinyl)-10,11-dihydro-9H-isothiazolo[4',5':5, 
6]pyrido[1,2,3-mn]phenoxazine-9,10-dione (I') 
##STR66## 
R=1,3--di F). 
(c) 
1,3,7-trifluoro-6-(3-(ethylamino)methyl-1-pyrrolidinyl)-10,11-dihydro-9H-i 
sothiazolo[4',5'-5,6]pyrido[1,2,3-mn]phenoxazine-9,10-dione (I') 
##STR67## 
R=1,3--di F). 
EXAMPLE 24 
1,3,7-trifluoro-6-(3-amino-1-pyrrolidinyl)-10,11-dihydro-9H-isothiazolo[4', 
5':5,6]pyrido[1,2,3-mn]phenoxazine-9,10dione 
By following the procedure as Example (18), the product of Example 23(b) 
can be hydrolyzed to yield 
1,3,7-trifluoro-6-(3-amino-1-pyrrolidinyl)-10,11-dihydro-9H-isothiazolo[4' 
,5':5,6]pyrido[1,2,3-mn]phenoxazine-9,10-dione hydrochloride salt (I') 
##STR68## 
R=1,3--di F). 
EXAMPLE 25 
In the described fashion as Example 15(b), replacing methyl 
N-(2-fluorophenyl)iminochlorothioformate (4') (R=H) with an appropriate 
N-substituted iminochloroformate (4') such as R equals to 
4,5-methylenedioxy, 4-hydroxy, 4-methoxy, or 4-methyl one can obtain the 
following 1,4-dihydro-4-oxo-quinoline-3-carboxylate (5')(a), (b), (c) and 
(d) 
(a) Compound (5') R=m,p-methylenedioxy 
(b) Compound (5') R=4-hydroxy 
(c) Compound (5') R=4-methoxy 
(d) Compound (5') R=4-methyl 
EXAMPLE 26 
By following Example 15(c-f), the preceding compound (5')(a), (b), (c) and 
(d) can yield the following compounds: 
(a) 
2,3-methylenedioxy-6,7-difluoro-10,11-dihydro-9H-isothiazolo[4',5':5,6]pyr 
ido[1,2,3-mn]phenoxazine-9,10-dione (9') (R=2,3-methylenedioxy). 
(b) 
3-hydroxy-6,7-difluoro-10,11-dihydro-9H-isothiazolo[4',5':5,6]pyrido[1,2,3 
-mn]phenoxazine-9,10-dione (9') (R=3--OH). 
(c) 
3-methoxy-6,7-difluoro-10,11-dihydro-9H-isothiazolo[4',5':5,6]pyrido[1,2,3 
-mn]phenoxazine-9,10-dione (9') (R=3--OCH.sub.3). 
(d) 
3-methyl-6,7-difluoro-10,11-dihydro-9H-isothiazolo[4',5':5,6]pyrido-[1,2,3 
-mn]phenoxazine-9,10-dione (9') (R=3--CH.sub.3). 
EXAMPLE 27 
In the described fashion as Example 15(g), using compounds in Example 
25(a-d) instead of compound (9') (R=H) and replacing N-methylpiperazine 
with an appropriate amine such as 3-methylamino-pyrrolidine, 
3-hydroxypyrrolidine, 3-hydroxymethylpyrrolidine, N-methylhydrazine, 
1,2-diaminoethane, ethanolamine, ethylamine and 
2-p-fluorophenylpiperazine, one can obtain the following compounds. 
(a) 
2,3-methylenedioxy-6-(3-methylamino-1-pyrrolidinyl)-7-fluoro-10,11-dihydro 
-9H-isothiazolo[4',5':5,6]pyrido[1,2,3-mn]phenoxazine-9,10-dione (I') 
##STR69## 
R=2,3-methylenedioxy.) 
(b) 
3-hydroxy-6-(3-hydroxy-1-pyrrolidinyl)-7-fluoro-10,11-dihydro-9H-isothiazo 
lo[4',5':5,6]pyrido[1,2,3-mn]phenoxazine-9,10-dione (I') 
##STR70## 
R=3--OH). 
(c) 
3-methoxy-6-(3-hydroxymethyl-1-pyrrolidinyl)-7-fluoro-10,11-dihydro-9H-iso 
thiazolo[4',5':5,6]pyrido[1,2,3-mn]phenoxazine-9,10-dione (I') 
##STR71## 
R=3--OCH.sub.3). 
(d) 
3-methyl-6-(2-methyl-1-hydrazyl)-7-fluoro-10,11-dihydro-9H-isothiazolo[4', 
5':5,6]pyrido[1,2,3-mn]phenoxazine-9,10-dione (I') (Z=NHNHCH.sub.3, 
R=3--CH.sub.3). 
(e) 
3-methyl-6-aminoethylamino-7-fluoro-10,11-dihydro-9H-isothiazolo[4',5':5,6 
]pyrido[1,2,3-mn]phenoxazine-9,10-dione (I') (Z=NHC.sub.2 H.sub.4 NH2, 
R=3--CH.sub.3). 
(f) 
3-methyl-6-hydroxyethylamino-7-fluoro-10,11-dihydro-9H-isothiazolo[4',5':5 
,6]pyrido[1,2,3-mn]phenoxazine-9,10-dione (I') (Z=NHC.sub.2 H.sub.4 OH, 
R=3--CH.sub.3). 
(g) 
3-methyl-6-ethylamino-7-fluoro-10,11-dihydro-9H-isothiazolo[4',5':5,6]pyri 
do[1,2,3-mn]phenoxazine-9,10-dione (I') (Z=NHC.sub.2 H.sub.5, 
R=3--CH.sub.3). 
(h) 
3-methyl-6-(3-p-fluorophenyl-1-piperazinyl)-7-fluoro-10,11-dihydro-9H-isot 
hiazolo[4',5':5,6]pyrido[1,2,3-mn]phenoxazine-9,10-dione (I') 
##STR72## 
R=3--CH.sub.3). 
It will be understood that various changes and modifications can be made in 
the details of procedure, formulation and use without departing from the 
spirit of the invention, especially as defined in the following claims.