Note: Descriptions are shown in the official language in which they were submitted.
9~
This is a divisional appli.cat:ion o:E Canad.ian pa-tent
application serial number 302,421 Eiled on MaY 2, 197~.
SUMMARY OF THE INVENTION
This invention provi.des, i.n one aspect thereof,
aylycones of the formula II (which are derivatives o:E dauno-
mycinone)
3 (II~
OH O ORl
wherein Rl is a lower alkyl having 1 to 4 carbon atoms.
In another of its aspects, the invention provides a
new process for the preparation of compounds of the yeneral
formula II which comprises:
(a) react:ing a compound of the formula (IV)
o OCOOC2H5 o
~ CH3
OCH3 OCOOC2H5
:~: OCooc2H5
:~ with aluminum trichloride in an oryanic solvent to produce
a compound of the formula ~V)
O OH o
~ CH3 (V)
3~ OH O OCOOC H
~: QCOOC~H5 2 5
~L~gg76~
.
1 (b) reacting -the compound oE the formula (V) wi-th a benzyl
halide in the presence o a base in an organic solvent
at ~ tempera-ture of from about 20C Io about 100C to
produce a compound of the formula (VI)
~ C-~3 ~VO
CH 2 C 6 H 5 OCOOC 2H 5
(c) treating the compound of the formula (VI) with a dilute
alkaline hydroxide or with a basic resin to produce a
compound of the formula (VII)
CH2Ci;H5 ~
9 (VII~
2 6 5 OH oR2
...
wherein R2 is hydrogen when the treatment is carried aut
in an aqueous medium and is an alkyl residue
when the treatment is carried out in an alcohol
solvent,
td) reacting the compound of the formula (VII) with a halide
of the general formula Rl-Y wherein Rl is defined herein-
before and Y is selected from the group consisting of
chlorine, bromine and iodine, to produce a compound of
the general formula ~VIII~
~' .
~9~
C1~12C6H5
~ 3 ~VIII~
Rl ~R2
2 6 5
wherein Rl and R2 are defined hereinbefore,
1~ (e) reacting the compound of the general formula (VIII~ with
trifluoroacetic acid at room temperature to produce a
compound of the formula IIX~
~ ~ 3
OH ORl OR2
wherein Rl and R2 are defined hereinbefore; and
~ (f) hydrolyzing the compound of the formula (IX~ in boiling
aqueous trifluoroacetic acid to produce the compound
:~ of the general formula ~ and its 7-epimer.
These compounds are useful in the preparation of a
new class of daunom~cin derivatives of the formula II):
~:.
, :
-::
-3-
~ J'~C}13
; ~ ~ ~ /j 7~ O~I
0~1 o ~ ~
~ I
37 o ~
~ NH-R
0~ .
wherein Rl is a lower alkyl having rom 1 to 4 carbon atoms and
R is hydrogen or a trifluoroacetyl group.
These compounds are prepared from the respective
aglycones of the formula II (which are derivatives of daunomyci-
; none) by condensation with an N,0-protected daunosamine
derivative. The aglycones of the formula II: -;;
O OH ~ ;~
}l3
¦ H OH II ~ :
)H OR
~1 0
wherein Rl is as defined abover are another aspect of the
invention.
The aglycones of the formula II are in turn prepared
. from daunomycinone III according to the following sequence:
:, .
~ .
-4-
7~ '
." ~ .,
, ~ O O
o ----o ~-- ~ o ~"
o--~-o o-~o
H ~q
O
I D ~
~\ 3Ul (>"Om~ C~
~ ~ O O
~oO,, ~ocN T
7~
1 wherein Rl is as defined above and R2 is as d~Eined hereinaf-tex.
~s described in co-pending application Serial No.
290,848, filed November 14, 1977, daunomycinone I:[I can be
easily conver-ted to the triethoxycarbonyl derivative IV. We have
now ~urprisin~ly found that compound IV reacts ~ith aluminum -tri-
chloride in an organic solvent such as dichloromethane, chloroEorm
and the like, to aEford the bis-phenolic compound V by an un~
expected, simultaneous cleavage of the phenolic methyl ether in
the ~-position and of the carbonate moiety in the ll-position.
1~ Compound V is thus the key intermediate of the present synthesis.
In fact, the reaction of compound V with a benzyl halide in the
presence of a base such as silver oxide, potassium carbonate and
the like, in a suitable organic solvent and at a temperature of
20 to 100C, yields the dibenzyl derivative VI. The latter, on
treatment with a dilute alkaline hydroxide or with an activated
basic resin such as AGl-X2 and the like, gives rise to the
monophenolic compound VII, wherein R~ is hydrogen when the
reaction is carried out in aqueous medium, and preferably, is an
alkyl residue when an alcohol, such as methanol, is used as the
2Q solvent. Another key step in this synthesis is the reaction of
the phenolic hydroxyl group of compound VII (R2 = CH3) with a
halide of the general formula Rl-Y, wherein Rl is as defined
above and Y is Cl, Br, or I, to afford the new ethers of the
formula VIII ~R2 = CH3). This reaction is run in a boiling
organic solvent such as dichloromethane, chloroform, dichloro-
ethane and the like in the presence of a base such as silver
oxide, potassium carbonate and the like. Selective removal of
the benzylic groups of compound VIII (R2 = CH3) is achieved by
brief treatment with trifluoroace-tic acid at room temperature
with the formation of the bisphenolic compound IX (R2 = CH3).
Finally the C-7 methyl e-ther is hydrolyzed in boiling aqueous
6--
~ ~9 ~t~ ~
1 tri:Eluoroacetic acicl to a.Eforcl-the new ~glycon~ 1~, toclether
w1.th small amounts o:E the 7-epi.mers -the~eof. 'rhe latter
can themselves be transformed into aglycones :[I/ having the
7-~-0~1, foll.owing the equilibra-tion method report~d by Kende in
~.~m.Chem.Soc. g8, 1967 (1976). The bi.ologically ac-tive glycosides
of formula I are prepared by con~ensing an aglycone of the
formula II (.according to the procedure for the synthesis
of glycoside linkages described in Belgian Patent No. 842,930
owned by the unrecorded assignee hereof) with a protec-ted 1-
halo-sugar in a suitable organic solvent, such as dichloromethane
or chloroform, in the presence of a soluble silver salt as a
catalyst. In the present case, the aglycone II is condensed . .
-~ with l-chloro-N,0 bis-trifluoroacetyldaunosamine, to form the N,0
protected glycoside X wherein R1 is as defined above:
J ~ Ol 3
OH 1 q
~O ~ /~
COCF3 X
F3 .:~
The N,0 protected glycoside X, on tre~tment with
methanol and a catalytic amount of triethylamine, is converted
into the N-trifluoroacetyl protected glycoside which can be
successively hydrolyzed, by mild exposure to a dllute alkaline
hase, to form the free glycosidic base which is finally isolated
as the hydrochlorlde. Compounds I display antimitotic activity
and they are useful therapeutic agents for the trea~ment of
certain mammalian tumors.
7~
1 DESCRIPTION OL` THE PRF,E'ERRE,D E:MNODCME,N'rS
The followin~ examples are given to illustrate the
invention by describiny the preparation o~ compounds accordiny to
the invention and -their use, without, however, being a limita-tion
thereoE~
X~MP~E 1
4-Demethoxy-4-hydroxy 06,07-bi_ _hox~carb yldauno~ycinone
To a solution of 30 g. of o6,o7,0 l-txis-ethoxycarbonyl-
daunomycinone in 500 ml. of chloroform, 30 g. of granularaluminum trichloride were added under vigorous stirring. Two
further addi-tions, each one o~ 30 g. of aluminum trichloride,
were made af-ter 1 hour and 1.5 hours, respectively. After
stirring for two hours, the reaction mixture was poured in-to 2
liters of a cold aqueous solution of oxalic acid and extracted
with chloroform. Tne organic layer (chloroform) was washed with
an aqueous solution of sodium bicarbonate, then with water and
finally was dried over sodium sulfate. The solvent was evaporated
in vacuo and the residue was crystallized from a mixture of
X~ ethyl acetate-benzene -to yield 13 g. of 4-demethoxy-4-hydroxy-
06,07-bis-ethoxycarbonyldaunomycinone.
PMR (CDC13): 1.33 and 1.43~ ~two t, CH3-C(ll2)), 2.40~ (s, CH3CO),
4.23 and 4.33~ (two q, CH2-C(CH3)~, 6.13~ (broad s,
C-7-H), 6.9-7.8~ (m, 3 aromatic protons~, 12.45 and
13.4~ ~two s, phenolic hydroxyls).
IR (KBrl: 1775, 1750, 1710, 1625, 1600 and 1585 cm 1
EXAMPLE 2
4-Demethoxy-4-hydroxy-11-deoxy-4,11-dibenzyloxy-06,07-bis-
ethoxycarbonyldaunomycinone
A solution o 5 g. oE 4-demethoxy-4-hydroxy-06,07-bis-
--8-
g9~i~QEà
1 ethoxycarbonyldaunomycinone in 250 ml. oE dichloromethane was
treated with 5 ml. of benzyl bromide and 5 g. of silver oxide and
re:Eluxed :Eor two hours. After cooling, the reac-tion mixture was
~i:ltered and the solvent evaporated in vacuo. The resulting oily
residue ~as washed several times with pe-troleum ether until .it
became solid and was then crys-tallized :Erom a mlxture of dichloro-
methane-benzene to aEford 6 g. oE 4-demethoxy-4-hydroxy-11-
deoxy-4,11-dibenzyloxy-06,07-bis-ethoxycarbonyldaunomycinone.
PMR (CDC13): 1.30 and 1.40~ (two t, CH3-C(H2)), 2.23~ (s, CH3C0),
4.23 and 4.30~ (two q, CH2C(H3)), 5.00 and 5-23~
;~ (two s, 0-CH2-C6(H~)), 6.23~ (broad s, C-7-H), 6.9-
7.9~ (m, 3 aromatic protons).
IR (KBr): 1770, 1745, 1717, 1680 and 1590 cm 1
.
EXAMPLE 3
4-Demethoxy-4-hydroxy-7,11-bis-deoxy-4,11-dihenzyloxy-7-
methoxydaunomycinone
;
A solution of 5 g. of 4-demethoxy-4-hydroxy-11-deoxy-
4,11-dibenzyloxy-06,07-bis-ethoxycarbonyldaunomycinone in 15 ml.
of dichloromethane and 100 ml. of methanol was treated with an
excess of AGl-X2 resin which had been previously activated with
aqueous sodium hydroxide and washed with methanol. The reaction
mixture was stirred at room temperature until the starting
material had completely reacted, and then lt was filtered and
evaporated to dryness. The resulting residue was chromatographed
(silica gel; chloroform-acetone 95:5, v/v) to give 3 g. of 4-
demethoxy-4-hydroxy-7,11-bis-deoxy-4,11-dibenzyloxy-7-
methoxydaunomycinone.
: ;
3~
1 PMR (CDC13): 2.30~ (s, CH3CO), 3.60~ (s, cll3n) / 4.93~ (9,
O-CH2-C6(El5) and C-7-H~, 5.31~ (s, 0-CL12-C6(~15)),
7.2-8.0~ (m, 3 aromatic protons), 14.2~ (s,
phenolic hydroxyl).
IR (KBr): 1726, 1681, 162~, 1587 and 1572 cm
EXL~MPIE 4
4-Deme-thoxy 4-hydroxy-11-deoYy-4,11-diberlzyloxydaunomycinone
The title compound was obtained from 4-demethoxy-4-
hydroxy-11-deoxy-4,11-dibenzyloxy-06,07 bis ethoxycarbonyldauno-
mycinone following the procedure described in Example 3, except
~ that aqueous dichloromethane and wet resin were used in place
; of the methanol~
PMR (CDC13) 2.26~ (s, CH3CO), 4-90~ ~s, 0-CH2-C6(H5)~, 5.30
(s, O-CH2C6(H5) and C--7-H), 6~9--7.9~ (m, 3 aromatic
protons), 14.3~ (phenolic OH).
EXAMPLE 5
.
4-Demethoxy-4-hydroxy-6,7,11-tris-deoxy-4,11-dibenzyloxy-6,7-
dimethoxydaunomycinone
1.5 Grams of 4-demethoxy-4 hydroxy-7,11-bis-deoxy-4,11-
dibenzyloxy-7-methoxy daunomycinone were dissolved in 200 ml. of
dichloromethane containing 20 ml. of methyl iodide and
refluxed under stirring in the presence of 1.5 g. of silver
oxide. After 24 hours the reaction mixture was cooled and left
to stand overnight at room temperature. The inorganic solid
which precipitated was filtered off and the solvent evaporated
in vacuo to yield 4-demethoxy-4-hydroxy 6,7,11-tris-deoxy-4,11-
dibenzyloxy-6,7-dimethoxydaunomycinone in almost quantitative
yield.
~10--
1 P~IR (CDCl3): 2-33~ (s, CE13C0~, 3.53 ancl 3.93~ (two s~ C~130),
5.00 and 5.26~ (-two s, 0-C~L2-C6(~l5)), 7~0-7.9~ ;
(m~ 3 aromatic protons).
EXAMPLE 6
4-Demethoxy-~-h~ -6,7-bis~deoxy-6 ! 7-dimc thoxydaunomycinone
1.5 Grams of 4-demethoxy-4-hydroxy-6,7,11~tris~deoxy-
4,11-diben2yloxy-6,7-dime-thoxydaunomycinone were dissolved in 50 ml.
of trifluoroace-tic acid containing 2% o~ water and the solution
l~ was lef-t to s-tand a-t room -temperature for 3 hours. The acid
was removed in vacuo and the residue dissolved in the minimum amount
of acetone, treated with concentrated aqueous ammonia and finally
diluted with ethyl acetate. Af-ter several washings with water,
the organic layer was dried over anhydrous sodium sulfate. The
solvent was removed in vacuo to afford 4-demethoxy-4-hydroxy-6,7-
bis-deoxy-6,7-bis-methoxydaunomycinone in 90~ yield.
PM~ (CDC13): 2.40~ (s, CH3C0), 3056 and 3~90~ ~two s, CH30),
4.80~ (broad s, C-7-H~, 6.7--7.8~ (m, 3 aromatic
pro-tons), 12.9 and 13.5~ ~aromatic hydroxyls).
~ EXAMPLE 7
4-Demethoxy-4-hydroxy-6-deoxy-6~methoxydaunomycinone and its
~er
A solution of 1.5 g. of 4-demethoxy-4-hydroxy-6,7-bis-
deoxy~6,7~bis-me-thoxydaunomycinone in 50 ml. of trifluoroacetic
acid containing 2% of water was kept at 60C. for 2 hours. The
acid was removed in vacuo and the residue dissolved in acetone
and hydrolyzed with concentrated a~ueous ammonia. The reaction
mixture was diluted with chloroform, washed with water and
3~ evaporated to dryness. The resulting residue was chroma-tographed
~silica gel, chloroform-acetone 95:5~ v/v) to give two products:
- 1 4-deme-thox~--4-hyclroxy-6-cleoxy-6-metho~ydaunomycinone (RE 0.~3 on
silica gel plate; chloroform-acetone 4:1, v/v) ancl :i-ts 7-epimer
(RE 0.3) in a ratio of 8:2. :[f desired,the 7-epimer can be
readily converted to the natural conEigur.a-tion by treatment wi.th
trifluoroace-tic acid.
PMR (CDC13) of 4-demethoxy-4-hydroxy-6-deoxy-6-methoxydaunomy-
cinone: 2.43~ (s, CH3C0), 3.96~ (s, CM30), 5.20~ (broad s,
C-7-H), 7.0-7.8~ (m, 3 aroma-tic protons), 12.~ and
13.5~ (two s, phenolic hydroxyls).
~ IR (CDC13): 1718, 1625 and 1585 cm 1.
EXAMPLE 8
4-Demethoxy-4-hydroxy-6-deoxy-6-methoxy-N-trifluoroacetyl-
daunomycin _ _ _ __
To a solution of 1.5 g.of 4-demethoxy-4-hydroxy-6-
deoxy-6-methoxydaunomycinone and 1.25 g. of 2,3,6-trideoxy-3-
trifluoroacetamido-4-0-trifluoroacetyl-~-L-lyxopyranosyl chloride
(l-chloro-N,0-bis-tri:Eluoroacetyldaunosamine) in 100 ml. of
anhydrous dichloromethane, a solution of 0.95 g. of silver tri-
20. fluoromethanesulphonate in anhydrous diethyl ether was added
. dropwise at room temperature under stirring. After 1 hour, the
reaction mixture was washed with aqueous NaEIC03 and evaporated
to dryness. The resulting residue was dissolved in methanol
containing a catalytic amount of triethylamine and left to stand
at room temperature for 2 hours. The solvent was removed in vacuo
and the residue chromatographed ~silica gel; chloroform acetone
95:5, v/v) to give pure 4-demethoxy-4-hydroxy-6-cleoxy-6-methoxy-
N-trifluoroacetyldaunomycin.
PMR (CDC13): 1.31~ (d, CH3-C(H)/ ), 2~40~ (s, CI13-C0), 3.86
(s, CI-I30), 5.20~ (s, C-7-H), 5.36~ (s, C-l'-H)
-12-
~ 3~r7~6
i 7.0-7.9~ (m, arorlatic II), 12.83 and 13.53~ (two s,
phenolic ~1).
EXAMPLE 9
~-Demetho~y-4-hydxoxy-6-deoxy-6-methoxydaunomycin hydrochloride
1.0 Gram of 4-demetho~y-4-hyd:L~oxy-6-deoxy-6-I~letho~cy-N-
trifluoroace-tyldaunomycin was dissolved in 50 ml. of aqueous
0.15N NaOH and left to stand for 1 hour at room temperature.
After acidification with oxalic acid and rapid neutralization with
aqueous NaHC03, the product was extracted with chloroform and
the chloroform extract was evaporated to dryness. The resulting
residue was dissolved in dichloromethane and -treated with 1
equivalent of HCl in methanol. Upon the addition of diethyl
ether, 4-demethoxy-4-hydroxy-6-deoxy-6-methoxydaunomycin hydro-
chloride was precipitated and collected by filtration.
Rf = 0-58 (CHC13-C~30H-H20 = 13:6:1 ~/v~
- 481 nm
max
PMR (CDC13): 1.26~ ~d, CH3-C(~ ), 2.40~ (s, CH3CO), 3.90~ (s,
CH30~, 5.20~ ~s, C-7-H), 5.36~ ~s, C~ l), 7.0-
7.9~ (m, aromatic H~
BIOLOGICAL ACTIVITY
4-Demethoxy-4~hydroxy-6-deoxy~6-methoxydaunomycin was
tested under t~e auspices of N.C.I., National Institute of Health,
Bethesda, Maryland,U.S.A. against Lymphocytic Leukemia P38~
according to the procedure described in Cancer Chemotherapy
Reports, Part 3, Vol. 3, page 9 ~19721. The following Table
illustrates the antitumor activity of this new anthracycline
compound.
The new-compound was compared to daunomycin in a test
in which mice infected with tumor cells were injec-ted with the
~13-
~9~
two compounds on days 5, 9 and 1.3 ~ith a 4 clay interval between
each single injection starting :Erom the fif-th day after tumo:r
transplantation in mice.
r.rABLE ___ __
.~ r-
Compound Schedule of Dose T/C ~
Days~(i p _ _ mg./kg. ~_
_
Daunomycin.HCl 5,9,13 16 0 148
8.0 129
4.0 120
2.0 119
4-Demethoxy-4-hydroxy- 5,9,13 50.0 124
6-deoxy-6-methoxy- 12 5 129
daunomycln.HCl 6 25 118
3.13 114
_
Modifications and varia-tions can, of course, be made
without departing from the spirit and scope of the invention.
.
3~
