CA1175819A - 6"-deoxydibekacin, 4",6"-dideoxydibekacin and i-n- aminoacyl derivatives thereof, and the production of these new compounds - Google Patents

Abstract

6"-DEOXYDIBEKACIN, 4"6"-DIDEOXYDIBEKACIN
AND 1-N-AMINOACYL DERIVATIVES THEREOF,AND
THE PRODUCTION OF THESE NEW COMPOUNDS

ABSTRACT OF THE DISCIOSURE
New compounds, 6"-deoxydibekacin, 4",6" dideoxy~
dibekacin, 1-N-(L4-amino-2-hydroxybutyryl)-6"-deoxy-dibekacin and 1-N-(L-4-amino-2-hydroxybutyryl)-4",6"-dideoxydibekacin are now produced semi-synthetically from dibekacin, i.e. 3',4'-dideoxykanamycin B. These four new compounds are each useful as an antibacterial agent.
Production of 6"-deoxydibekacin or 4",6"-dideoxydibekacin is made by removal of the 6"-hydroxyl group or by removal of the 4"- and 6" hydroxyl groups from an amino-protected and hydroxyl~protected derivative of dibekacin. Production of 1-N-(L-4-amino-2-hydroxybutyryl)-6"-deoxydibekacin or -4",6"-dideoxydibekacin is made by acylating the 1-amino group of 6"-deoxydibekacin or 4",6"-dideoxydibekacin with the L-4-amino-2-hydroxybutyryl group, or alternatively by removal of the 6"-hydroxyl group or the 4"- and 6"-hydroxyl groups from a known compound, 1-N-(L-4-amino-2-hydroxy-butyryl)-dibekacin.

Description

3 .1~5~19 This is a division of copending a~plication serial no. 357,816, filed August 7, 1980 ~ACE~ROUND O~ ~ INVEI~IO~
Field of the invention This invention relate~ to new semi-synthetiG amino-glycosidic antibiotic~9 particularly 6"-deoxydibekacin, 4",6"-dideoxydi~ekacin, 1~ 4-amino-2-hydroxybut~ryl)-6"-deoxydibekacin and l-N (I.-4-amino-2-hydroxybutyryl)-4"96"-dideo~ydibekacin which are each the new compound u~eful as antibacterial agents~ Th~s in~ention also relates to processes for -the production of these new compounds, Thi~ invention further relates to an antiW
bacterial composition comprising one of the~e new compou~d~
: as the active ingredient.
Descript~on of the prior art Dibekacin, namely ~ dideo~ykanamycin ~ wa~ semi-synthetically produced from kanamycin ~ by the presentinventors (see Japanese patent publication No. 7595/75;
Japanese patent ~o. 794,612; U.S. patent ~o. 3,75~,973~.
Dîbekacin has been used extensively in therapeutic treat-ment o~ various bacterial in*ections as a chemotherapeutic agent which ls active against the kanamycin-sen~itire bacteria and also against various kanam~cin-resi~tant bac-~eria~ We, the present inventors, produced semi-syntheticallg l-N~ 4-amino-~-hydro~ybu-tyryl)-dibe~acin which i8 a chemotherapeutic agent e~fective again~t dibekacin-resistan~ bacteria (see JapanQ~e patent publi-cation No. ~3~629/77; U.S~ patent Nou 4,107,424). Recently, we also produced semi-synthetically 6"-deoxyamikacin .` ~k 15~7~19 (i,e~ l-N~ 4-amino-2-hydroxybutyryl)-6"-deoæykanamycin A) and 4",6"-dideoæyamikacin (i.e. 1-N-(L~4-amino 2~hydro~y-b~tyry~)-4",6" dideoæykanamycin A) (Japane~e patent appli-cation No. 54733/79) which each have a low oto-toxicit~
and are confirmed to show an antibacterial activity as hlgh a~ that o~ ~mikacin9 namely 1~ 4-amino-2-hydroæy-butyryl)-kanamycin A~
~U~MARY 0~ THE INVFNTION
In our ~urther re~earches9 we have now sucGeeded at first time in synthetioally producing the new 6'~-deoxy or 4",6i'-dideo~y derivative~ o~ dibekacin and 1~ 4-amino-

- 2-hydroxybutyrgl~-dibekacin, respectively. Furthermore, ue have ~ound that these new 6"~deoæy derivatives and 4"36"~dideoxy derivatives now synthetized e~hibit not only a low oto-to~icity but al~o ~how an antibacterial activity as high a~ that of dibekacin or 1 N~ 4-amino-2-hydro~y-butyryl)-dibekacin~
DETAILBD DESCRIPTION OF THE I~VENTIO~
According to a flr~t aspect of this i~vention, there-~ore~ there i~ provided a~ a new compo~nd a deoæy derivative of dibakacin repre~ented by the general ~ormula (I~

~ 1~5~

R ~ ~ \ ~ ~ ~L~
~2~ ~ 0 2 (I) 0 ~

H2N ~ ~g2 ~herein R i~ a hydro~yl group or a hydrogen atom, a~d an a~id addition ~alt thereo~. The new compoùnd of the above formula (I) where R is a h~dro~yl group i~ 6" deoxydibekacin, and the new compound of the formula (I3 where R is a hydrogen atom is 4",6"-dideoxydibekacin.
According to a ~econd a~pect of this invention9 there is provided as a new compound a deoxy derivative of l-N~ 4-amino~2-hydroxybutyryl)-dibekacin repre~ented by the general formula (II) ~75~9 H2~ ou ~ OH 7 O ~ ~ ~ (II) HN ~ ~ NH2 ~ CO
CHOE
l~2a~2~H2 wherein R is a hydro~yl group or a hydrogen atom, and an acid addition salt thereo~. The new compound of ~he above formula (II) where R is a hydroxyl group is 1~ 4-2mino-2-hydro:~:ybutyr~ 6"-deoxydibekacin, a~d the new compou~d o~ the ~ormula (II) where R is a hydrogen atom i~ l-N-(I~4-~mino-2-hydro~ybutyrylj-4" 9 6"-dideoxydibekacin.
The physico-chemical and biological propertis~ o~
the above-mentioned four new compounds according to the first and second a~pect~ o~ this in~ention ar~ a~ f`ollows:-(l) 6"~-Deoxydibekacin ~esqui-carbona-te i~ a ~ub-~tance in the form of a colorle3~ powder decomposing gradually near 131~C and ~howing a speci~ic optical rotation ~a]26_ ~lOl~
(c 0.44, w~ter). It~ elemental analy~i~ i3 coincident with the theoretical values o~ Cl8~37N507 ~/ 2 3 H 7.63%, N 13.25~). In ma~ spectrometr~, it gave a value 7!58~9 of m/e 435 (M+). This substance give~ a single spot (positi~e to ninhydrin) at Rf 0.38 in a thin layer chromato-graphy on silica gel developed with a mixture of butanol-ethanol-chloroform water (4:5:2:5 by volume) as the develop ment solvent~
( 2 ) 4 ", 6 "-Dide oxydibe~acin sesqui-carbonate is a substance in the form of a colorless powder decomposing gradually ne~r 129~ and showing a specific optical rotation ~]D3 = + 126~ (c 0.5, water). It~ elemental analysis i~
coincident with the theoretical values o~ ~18H~7N~06-3/2 H2C03 (~ 45~69%, H 7.87%, ~ 13.66%). In mass spectrometeryD it gave a value o~ m/e 420 (M ~ his substance gives a single spot (positive to ninhydrin) at Rf Ob45 in the above-mentioned ~ilica gel thin layer chromatography.
(~) 1 N~ 4-amino-2rhydro~ybutyryl)-6"-deoxy-dibekaci~ sesqui-carbonate is a substance in the form of a colorless powder decomposing at 132-1~gC and showing a specific optical rotation ~a]23 = + 73o (c 0.3, water).
Its elemental analysis is coincident with the theoretical 22H42~69 3/2H~c03 (c 44. 97~o, H 7. ~3~ 13 395~) Thi~ sub~tance gi~es a single spot (positive to ninhydrin) at Rf` 0.10 in the above-mentioned silica gel thi~ la~er chromatograph~
(4) l~N-(Lr4 amino-2-hy~ro~yhu~ryl)-4",6"-dideox.vdibekacin se~qui-carbonate is a sub~tance in the ~orm o~ a colorless powder ha~ing a decomposition point at 142~147C ~nd showing a speci~ic optical rotation [a~24 - ~ 84 (c 0.5, water).

~ 175819 It~ elemental analy~is i~ coincident with the theoretical 22~4~N68 3/2 H2C03 (C 46-15~ H 7.42%, ~ 13.74~).
~his substance give~ a ~ingle spot at Rf 0.21 in the above-mentioned silica gel thin layer chromatographyO
Th~ minim~un inhibitory concentrationæ (mcg/m~) of 6"-deoxydibekacin (abbre~iated as 6"-DDBB)~ 4",6"-dideo~y-dibekacin (abbreviated a~ 4'1~6"-DDRB), 1~ 4-amino 2-hydroxybutyry~)-6"-deo~ydibekacin (abbreviated as AHB-6"
DDEB) and 1 N-~I,4-amino-2-hydro~ybutyryl) 4",61'-dideo~y-; 10 dibekacin (abbreviated as AHB-4'~,6'1-DDKB) of this invention against various microorganism~ were determined according to ~erial dilution method on a nutrient agar medium at ~7~C~
the estimation being made after 18 hours incubation. ~or compari~on purpose, the minimum inhibitory concentrations ~ dibekacin (abbreviated as DKB) were also determined in the same manner a~ ~tated above.
The antibacterial spectra of these new and known ~u~stances are shown in Table 1 below.

. , ~ ~ ~S~L9 __ .
=a) o ~D
. _ ~ C~l ~ Lr~~ P~ O ~ O ~ L~ a _ ~ o r~ JLS~ ~ ~ L(~ In 1 _ ~I r I r~ O
I ~ ~ ~ O O O ~ ~ O ~ ~ O O
~Q ~ V
~4Q
__ ~ . ~ ~
~ _ . .. _ ~~ O ~
1-1Ir~ N 1~ 15~ L~ tr~ O O o ~\ ~ 0~ .D CO
~ t-i r~ J ~ ~ t~ U~ L~
~_ _ ~ ~ O O O ~ ~ C~ ~i ~ O O
~3 ~
~~ ~ o ~
e~ iq ~ 0 0 0 ~ D W
~::1~ o - ~
Z. _1 O O ~ ~ O ~ o ~ o o _ ~ 1~ O O O O ~ O ~~I r-l Or-l ~ U~ ~ O
_ . r~

f~ CO O ~ ~D
~4 ~ c~ o In o~
~ . .. ~ t~ C~J C~J C~J 1~ Ll~ ~n In r l Q O O~ ~ o . a ~ N Lf ~ O O O tD L~ O' r~ r-l 0 ~1 r~ _ ~r~r C~ r~
n~ ~-,a:~ o ~D ~:7 ~ - - ------- _ _ ,, ,__ _ E~r~ o o o ~4 . ~c~l ~ ~m In 11 '. ~ V O ~ O
. ~ ~ O O O O O ~ O ~1 ~i ~ O ~
,~ o~ ~ ~ Lr~ 0~
_ ~ _ . , _ ,,, . ~_ , ~ O
O
r~ .
,~ 0 V 00 D ~ ~ O E~ 0 O E; ~~d ~ cn I O ,~
c~
O H ~ J CUC~
U~ ~D ~ C) V P~ rl ~ Il~--1 r-¦~1 .,1t1 - =rl ~ ; V P El --i ~ ~ O ~0 ~
~5 U) P H ~rl ~1 ~ ~ ~U a) . ~ tl~ ~ c) ~ 1 .~ E~ rl h rQ ~ r-l ~ Cd r~
O ~ ~ t~ r lrl :~ ~ O
C) C) ~ rl El c ) O O
' E~ C) ~ q C) -~ f-~ ~r r-l ' ., r-l O ~ ~q ~ Ul ~ -1~ 0 ~ ,0 C) ~r~
,S~ , o ~ h ~rl r~l r-l ~I r-l R ,o a~
a~ v c) ~J t ~rl ~1 ~ O ~
-1~ V V ~ V
.? ~ n~ ~S
rt? . ~ n r~ r~

9 ~ 8 1 9 r-i ~ o ~ O ~ 9 V
-O ~ 0~ 0 ,~
~i ~ Q O 1~ 0 0 0 0 0 0 S

- - - - - - - - - - - - - - - - - -tn. ~ ~ O m u~ ~i o ~ o ,i o O C~l ~ O O O

~- ~- ~- ~ ~ O Lt~ ~L ~ O ~ c, o o o ~ c~l ~) o o - - ~ L - - - - -c~o o ~ ~0 ~ ~-~
cC ~ ¢ ~ ~C) H
æ ,~ v ~I r~ ~3 r- r,l r-J r-l r-l r~ 1 C~
o h ~1 r-l ;~ h O C,~
,1 ., ~ a~ , I r~
h _ _ _ _ h _ _ _ rl 1~l ~1 ~, , ~

-- ~ . .... _ _ .. ~ ._ . . . ~ ._ , _ ~lo- 117~81~

O ~D O ~ ~ O ~ ~ O ~ ~ ~D
~ ~ O ~J O r~ L~ N 1::

~, .. . . _ . .. . . ._ . . . ~

~, ~ ~ o o ,~ ~ 8 ~ o ~ ~
. ' O ~D O ~ ~ C~ ~ ~ O O ~ C~J O ~ O
~ J l ~ ~ ~ .-, - - ~~~ ~~ r - - - ------ -- - - - . . _ _ __ _ _- _ - _ __ _ . .
Lr~ ~
~ o ~ o ~ ~ <:~ o g 8 ~t ~D N ~ ~
r~ ,~, r-~
. . _ _.. _ ~1~ -- --- j~_ , _ _ , ~D O ~ O ~D r-l O V g g O S~
~,t ~t r I ~ r-~,,,, ___ , , _ ,. 1.
N
r p~

t~ rl cn r-l ~lt ~ ~r ~t F r rt ~ rt C~ r-t r-l rt ~5 J a) rt S-l O ~ 1 0 Ulr~J ~3 d a~ h ~ ~ rl rl Ctl ~
~13~tt rr I 1> F I CIS ~ Id F~ t ~ i ~1~ c~ rl rl rl ~ (1~ El ,r~ ~ ~ r~ r~ O
a~ o o a) Q) a)c~ r-l ~1 r t~O~ E 1~ ~ t ~ h 5-~ h ~ p rl ~ r-- O O
~ t~ ~ h . . _ _ !

. . . , ~

LL~ ~ ~
.. ~, O ~ C~J O L~ O ~ O
o ,~ ~ ~ ~ ~ ~ o ~ ,~

~ U~
~ ~ ~ o C) o ~ o U~ ~ ~ o ~ o ~1 o ~, ~

, . . . ~

o o o ~ ~ o ~ o o o o ~ o ~ ~U o ~. ~1 ~,1 ~ ~ ,~

. _ . ... , L-~
~ ~U
C~ ~ O~ O O ~ O
O ~ U~ O O O ~
.. __ .
U~ ~
O O ~O O O ~D O
O U~ O O O ~
5~
. ~

~ O
LS~ ~ ~ ~ o rll ~1 0 Fq N P I FCI M
C) . ,1 R

o~
~q r~ = - = - - - r Q) ' Q) - 12 _ 1~758~9 ~ rom the above table, it is ~een that the ne~
compound~ of the general formulae (I) and (II) according to thi~ invention inhibit the growth o~ many kinds o~
bacterial strains. The new compounds of this in~en-tion e~hibit a low acute toxicity to animal~ and men. It ha~
bee~ e~timatea that the intra~enous ID50 of 6"-deo~y-dibekacin and 4?',6"-dideo~ydibekacin in mice were more than 60 mg~kg, and also that the intravenous ID50 o~
l-N-(I-4-amino-2 hydroxybutyryl)-6"-deoxydibekacin and l-N (I-4-amino-2~hydro~ybutyryl)-4"p6"-dideo~ydibekacin in mice were more th~n 80 mg/kg.
As compared to dibekacin (DEB~ 9 6"-deoxydibekacin and 4"96"-dideoxydibekacin of this ~nvention are 3ame or more active against ~anamycin-sensitive and re~istant bacteria. 1-N-(I~4-Amino-2-hydroxybu~yryl)-6"-deoxydibekacin and l-N (I~4-amino-2-hydroxybutyryl)-4",6"-dideoxydibekacin of thi~ inventlon show a similar activity to that o~ l-N-~I-4-amino-~ hydroxybutyryl)-dibekacin. ~iside3, 6"-deoxy-dibekacin~ 4",6"-dideoxydibekacin, l-N-(~-4-amino-2--hydro~y-butyryl)-6"-deoxydibekacin and 1-N~ 4-amino-2-hydrox~-: butyryl)-4",~"-diaeoxydibekacin o~ this invention ha~e a low oto-toxioity~
T'he new compounds o~ thi~ invention, that is, 6"-deoxydibekacin, 4",6"-dideo~ydibekacing 1-N-(I-4-amino-2-hydroxybutyryl)-6"-deoxydibekacin and 1-N~ 4-amino-2-hydroxybutyryl)-4",6"-dideoxydibekacin are usually obtained in the ~orm o~ its free base or a hydrate or a carbonate 1~7~9 ~ 13 thereof. ~he new compound~ o~ this in~ention each may readily be converted into a form of a pharmaceutically acceptable acid addition salt thereof, such as the hydrochloride, hydrobromide, ~ulYate t pho6phate, nitrate, acetate~ maleate, citrate~ a~corbate~ methanesulfonate and the like by reaeting with the appropriatey pharma-ceutically acceptable inorganic or organic acid in an aqueous medium.
~he new cempound~ of the formula (I) or (II) according to thi~ invention and its pharmaceutically acceptable acid addition ~alt may be admi~istered orally, intraperitoneally, intravenou~ly/ subcutaneously or in~ramuscularly using any pharmaceutlcal ~orm known to the art ~or such administration and in a similar manner to the known kanamycin~. For insta~ce, the new compounds of thi~ invention may be admini~tered orally using any pharmaceutical form kno~n to the art Yor oral administra-tion. Example~ of the pharmaceutical forms for oral administration are powdersg capsules, tablets9 syrup and the like. A suitable dose of the new compounds o~ this invention for e~ective treatment of bacterial in~ections is in a ran~e of 0.1 to l g. per person a day when it i~
given orally. It i~ preferred that said do~e should be orally administered in three to four aliquot~ per day~
The new compounds of this invention may also be admin-istered by intramuscular injec-tion at a dosage of 50 to 500 mg per person two to four times per day. Moreover, ~ 17~19 the new compounds of -this invention may b~ formulated into an ointment for external application which con-tains the active compound at a concentration o~ 005-5~ by weight in mixture with a known ointment base such as polyethylene glycol r ~urthermore, the new compound~ of this invention are each use~ul for sterilization o~ surgical instruments and sanitary material3.
According to a thlrd aspect of this invention, thereforep there i~ provlded an antibacterial compo~ition comprising as the active ingredient 6"-deoxydibekacin, 4";6"-dideoxydibekacin, l-N~ 4-amino-2-hydro~ybut~ryl)-6"-deo~ydibekacin or 1 ~ 4 amino-2-hydro~ybutyryl)-4",6"-dideoxydibekac~n or a pharmaceutically acceptable acid addition salt thereof, in an antibacterially e~ecti~e amount to i~hibit the growth of bacteria, in combination with a carrier for the active ingredient compoundO
Next, the production of the new compounds o~ the ~ormula (I) or (II) according to thi~ invention is de~-cribed.
6"-Deoxydibekacin and 4"~6"-dideoxydibekacin may be produced 3emi-synthetically starting from dibekacin~
~ 4-Amlno-2-hydroxybutyryl)-6"-deo~ydibekacin and l-N~ 4-amino-2-hydro~ybutyryl)-4",6"-dideoxydibekacin may be produced ~emi-synthetioally 3tarting from 1-~(I-4-amino-2-hydro~ybutyryl)-dibekacin. While, l-N-(L~4-amino-2-hydro~ybutyryl)-6"~deoxydibekacin and 1-N~ 4-amino-2-hydroxybutyryl)-4",6'~-dideoxydibekacin may also be 1 ~ 75~ ~ 9 produced semi-synthetically using 6"-deo~ydjbekacin and - 4",6"-dideo~ydibekacin, re~pectively, as the ~tarti.ng material.
According to a fourth a~pect of thi~ i~vention9 there ie provided a proces~ for the pxoduction of 6"-deo~ydibekacin or 4",6"-dideoæydibekacin of the ge~eral formula (I) c~3 R ~ H2N

E2N ~ OH
O ~ (I) wherein ~ i~ a h~dro~l group or a hydrogen atom (R i~ a hydroxyl group in re~pect of 6"-deoxgdibekacin while R is a hydrogen atom in re~pect of 4"~6"-dideoxydibekacin)~
which comprise~:-(a) protecting with a known amino-protecting group the ~ive amino group~ o~ dibekacin of the formula (III) .

I 375~9 -- 16 _ HO ~
~lo ~ 2 H ~H2 in a known manner to produce an amino-protected dibekacin derivative of the ~ormula ~III') Ht)~\ A
HO ~ \ B~
A ~ ~ ~ B

O ~
\ A (IIIl) A > ~ ~<

wherein A is a hydrogen atom and B i9 a mono-~alent amino~
protecting group, or A and B taken together ~orm a di-valent amino~protec-ting grOUp3 (b) protecting with a know~ di-valent hydro~yl-protecting group simultaneou~ly the 4"- and 6"-hydro~yl ~7581g group~ of the amino-protected dibekacin derivative (III') in a kno~n manner to produce a protected derivati~e o~ the formula (IIIIl) 6"

> N N < (III") wherein A and ~ have the ~ame meanings as defi~ed above and a group o~ the ~ormula X \ ~ i8 a di-valen~
y/
hydroxyl~protecting group where X and Y are hydrogen atoms both (i.e. methylene group), alkyl groups both (alkylidene group, particularly an isopropylidene group~, each a hydrogen atom and an alkyl group9particularly an alkyl group of 1~6 oarbon atom~ (alkylidene group), an aryl group, particularly a phenyl group (benzylideno group~ or an alkoxy group (alko~y-methylene group), or alternativel~ the group of the ~ormula X~ ~ i~ a cgcloalkylidene group, particularly a cyclohex~lidene group~
(c) protecting wi.th a known mono-valent hydroxyl-protecting group either the 2"-hydro~yl group alone or -31 1758~9 bo-th the 5- and 2" hydro~yl group~ of ~aid protected derivative (III") in a known manner to produce an amino protected and hydroxyl-protected dibekacin compound of the formula (IV) X
< A

>N < B

wherein A~ ~ and the group o~ the ~ormula ~ ~ / ha~e ~/ ~
the ~ame meaning~ as defined above, D i~ a mono valent hydro~yl prot~cting group in the form o~ an acyl group, particularly an alkanoyl ~uch a~ acetyl or an ~royl ~uch a~ ben~oyl, and E i~ a hydrogen atom or a mono-valent hydroxyl-protecting group in the form of an acyl group which may be the ~ame a~ or di~ferent ~rom the group D, (d) removing the group of protecting ~imult~neou~].y the 4"- and 6"-hydro~yl group~ o~ said protected dibekacin compound (IV) therefrom in a known manner to produce a partially protected dibekaoln compound of the ~ormula (V) I ~758~9 HO- \
A\ ~ Z<A
A>~ ~ (V) wherein A, B, D and E have the same meanings as de~:ined ab OV2 ~
(e) ~ulfonylating with a sulfonylating agent the 6"-hydro~yl group alone or s~multaneously both the ~11, and 6"-hydroxyl groups of said partially protected di-bekaoin compound (V) in a known manner to produce a mono-sulfonylated or di ~ulfonylated derlvative of the ~ormula ~V') GSO~ \

~OD ~

N < B

8 ~ ~
~ 20 -wherein A, ~, D and E have the same meanings as defined above, G is a lower alkyl group of 1~4 carbon atoms9 particularly methgl or ethyl 9 an aryl group such a~ phenyl group or p-methylphenyl group, or an aralkyl group, p~rticularly a phenyl-lower alkyl group ~uch a3 benzyl group, and G' is a hydroxyl group or i~ the same a~ the group GS03- ~hown in the formula (V')~
(~) reacting the 6"-mono-~ulfonylated or 4"~6"Wdi-3ulfonylated derivative (V') with an aIkali metal iodide or bromide in a known manner to replace -the 6"-sulfonyloxy group or the 4" and 6"-sul~onyloxy groups by iodo or bromo group, respectively, and thereby to produce the corresponding 6"-mono-iodo or bromo derivative or the corre~ponding 4"~6"-di-iodo or bromo derivative, (g) reducing said 6"-mono-iodo or bromo derivative or oaid 4",6'l~di-iodo or bromo derivative with hydrogen in the pre~ence o~ a hydrogenoly~is cataly~t to effect the dehalogenation and thereby to produce a corresponding 6"-mono-deoxy derivative (which i~ correspo~ding to such a compound o~ the ~ormula (V') but where the group GS03-ha~ been con~erted into a hydrogen atom and G' i~ remaining aa the hydroxyl group) or the corre~ponding 4"?6l'-dideoxy derivative (which i~ correspondlng to ~uch a compound of the formula (V') but where the group GS03- and the group G' oach have been converted into a hydrogen atom) represented by the formula (V") ~758~9 6"
C~
4" ~ O >N
\N ~ ~ ~ f o~<
/ O~ OE
O/~ 0 A~ N ~ < (~"~

wherein A9 ~ D and E are as de~ined above, and R is a hydroxyl group or a hydrogen a-tom, and - ~h) remo~ing the remaining ami~o-pr~tecting groups and the remaining hydroxyl-protecting groups from the 6"-mono-deoxy derivative or 4",6"-di-deoxy deriva~ive (V") in a known manner to produce 6"-deo~ydibekacin or 4",6"-dideoxydi~ekacin (I~
The process o~ the abo~e-mentioned ~ourth aspect of thi~ invention may~ if nece~sary~ include a further ~tep o~ converting 6"-deoxydibekacin or 4"~6"-dideoxy-dibekacin into a pharmaceutically acceptable acid additio~
3alt thereof.by reacting with a pharmaceutioally acceptable inorganio or organic acid in a known ma~nerO
The procedures for carrying out the proces3 ~or the production o~ 6"-deo~ydibekacin or 4",6" dideoxydibekacin are now describea.
In the ~irst step (a) o~ the present proces~, the

-3 17581g ~ 22 -five amino group3 o~ the ~tarting dibekacin (III) are protected with a known amino-protecting group in a known manner.
~he amino-protecting group available for the pro-tection of the amino groups of dibekacin may be any known amino-protecting group which is ordinarily u~ed in the conventional synthesis o~ peptideæ~ However, the amino-protecting group employed must be of the nature that it is removable readily by ~uch a procedure and under ~uch re-action condition~ which will substantially not break theglyco~ide li~kage o~ dibekacin when the removal o~ the amino~protecting ~roups is effected ~rom the amino~
protected 6"-deoxydibekacin or 4"~6"~dideo~ydibekacin as produced in the process of thi~ i~vention. Suitable e~amples of the mono-valent amino-protecting group which are available ~a~ the group 3) for the above purpose include an alko2ycarbonyl group o~ 2~6 carbon atom~ such a3 tert-butoxycarbonyl and tert-amylo~ycarbonyl; a cyclo-alk~loxycarbonyl group o~ 3~7 carbon atoms such as cyclo-he~ylo2ycarbonyl; an aralkyloxycarbonyl group ~uch a3benzylo~ycarbonyl and p-methoxybenzyloxycarbonyl; a~d a oubotituted al~anoyl group o~ 2~5 carbon atom~ ~uch as trifluoroacetyl and o-nitrophenoxyacetyl. Pre~erred e~ample~ o~ the di-valent amino-protecting group available (as the groupo A and B taken togother) ~or the above-mentioned purpo~ inelude phthaloyl g~oup and a group of Schi~ base type such as salicylidene. The introduction I ~ 75~ ~ 9 ~ 23 -of the amino-protecting group into dibekacin may be achie~ed by reacting the latter with an appropriate reagent ~or the introductio~ o~ the amino-protecting group which is in the ~orm of an acid halide, acid a~ide, active ester or acid anhydride, in the same manner as described e.g. in the speci~ications o~ U.S. Patent Nos~
~,929~762 and 3,939~14~ a~ well as ~.E. Patent No. 1,426,90~.
In the ~econd step (b) o~ the present process, the

4"- and 6"-hydroxyl groups of dibek~cin are protected qimultaneou~ly as a preliminary step for blocking the 2"-hydroxyl group occa~ionally together with the 5~hydroxyl group o~ dibekacin.
A~ the di valent hydroxyl-protecting group for protecting simultaneously both the 4"- and 6"-hydrogyl groups of dibekacin, there may be employed such a prot~ctive group which is frequently used ~or blocking the hydro~yl group~ of 1,3-glycol conventionalLy in the chemistry o~
sugar~. Suitable e~amples o~ the di-valent hydroxy:L-pro-tecting group ( X ~ ~ ) include an alkylidene group such a~ methylene, ethylidene and isopropylidene; ~1 aralkylidene group ~uch a~ benzylidene (when the alkylidene or aralkylide~e group is used ~or this purpose, the 4"-and 6"~hydroxyl g~oup~ are blocked by being con~erted into the ~orm o~ an acetal); a cycloalkylidene group such as cyclohexylidene and tetrahydro-4-pyranylidene (when the cycloalkylidene group is used for this purpose, the 4"-~ ~l 7~8 1 9 and 6"-hydroxyl groups are blocked by being con~erted into the form o~ a ketal); a lower aIkoxy-alkylidene group~
such a3 alkoxy~methylene, particularly methoxy-methylene (when the alko~y-a~kylidene group is employed for thi~
purpose, the 4-l_ and 6"-hydroxyl groups are blocked by being con~erted into the form of a cyclic ortho ester) and the like. In order to introduce the above di-valen~
hydro~yl~protecting group into the 4"-- and 6"-hydroxyl groups of the N-protected dibekacin derivative ~III'), the latter is reacted with an appropriate aldehyde or ketone in a known manner in the presence of an acid catalyst by exchange reaction with an acetal or a ketal or a~ orthoformate~ ~he N-protected dibekacin deri~ative ~III') may prefera~ly be reacted with formaldehyde or 2,2-dimethoxypropane for the alkylidenation; with benæaldeh~de for the aralkylidenation; with l,l-dimethoxy-cyclohexane for the cycloalkylidenation; or with trimethyl orthoformate for the alko~y-alkylidenation at a temperatura o~ e.g. 10~80C in the presence of an acid catalyst such a~ p-tolene~ul~onic acid or sulfuric acid in a known manner as de~cribed in U.S. Patent ~99299762, '~he above protection of the 4"- and 6" hydroxyl gIoups of the N-protected di-dekacin derivati~e (III') gi~e~ the 4",6't-0-protected dibekacin derivative (III") containing -the two hydroxyl groups which remain in the free ~tate at the 5- ~nd 2"-positions .
In the third step (c) of the present proces~ the 1~75~19 -- 25 ~

2'~-hydroxyl grOUp9 occasionally together with the 5-hydroxyl group of dibekacin, is protected in a known manner. As the available hydroxyl-protective group~ (D,E) for blocking both the 5- and 2"-hydro~yl groups or the 2"~hydro~yl group alone, there may be mentioned a mono-valent hydro~yl-protecting group which is an acyl group, particularly a lower alkanoyl group such a3 acetyl; or an aroyl group such a~ benzoyl. ~or the introduction of the mono-valent hydroxyl-protecing group (Dg~), the 4"~6"-O~protected dibekacin derivati~e (III") is acy1ated by reacting with an acid anhydride, acid halide or active ester o~ the acid which is containing the acyl group to be introduced into both the 5- and 2"-hydroxyl group~ or into the 2"- i hydroxyl group of the dibe~acin compound. The acylation may readily be achieved in a known manner. Thi~ acglation u~ually gives a larger proportion of the 2"-mono-0-acyl derivative and a minor proportion of the 5,2"~di 0-acyl derivative owing to that the 5-hydroxyl group is generally les~ reactive than the 2"-hydroxyl group. The 5,2"-di-0-acyl derivative a~ well a~ the 2"-mono-0-acyl derivative o~ the ~ormula (IV) may equally be utilized in the ~ext step (d) o~ the pres~nt proces~.
In -this way, the third step tc) of the pre~ent process affords the amino-protected and hyaroxyl-protected dibekacin compound (IV), and thi~ compound is then ~ub-~ected to the selective removal of the di-valent hydroxyl-protecting group ~ ~ from the 4"- and 6"-hydro~yl , C ~

1~7~8~9 groups there~rom. The reaction for selec-ti~ely removing the di-valent hydroxyl-protec-ting group may readily proceed by subjecting the dibekacin compound (IV) to hydrolysis under wea~ly acidic conditions in the presence of a weak acid ~uch a~ aqueoue acetic acid or diluted hyarochloric acid, giving the partially protected dibekacin compound (V) ~hich is an important intermediate useful in this irl~entio~.
This acid hydroly~is may usuall~ be effected at a t~mperature of 20C to 100C.
The partially protected dibekarin compound (V) ~o obtained is containing the liberated 4"- and 6"-hydroxyl group~. In order to achieve the production of 6"-deogy-dibekacin or 4",6"-dideogydibekacin according to this in~ention9 it is necessary to e~ect the removal o~ the 6"-hydro~yl group (~or the 6"-deoxygenation) or the removal of both the 4"- and 6"~hydroxyl groups from the partially protected dibekacin compound (V) (for the 4",6"-dideox~-genation). For thiq mono-deoxygenation or di-deoxygenation9 the following step~ are followed in the process o~ the fourth a~pect of thi~ in~ention.
Thu~, in the sul~onylation step (e) o~ the proce~s o~ the fourth aspect invention, the 6"-hydroxyl group or the 6"- and 4"~hydroxyl group~ oY the partially protected dibe~acin compound (V) i8 or are alkylsulfonylatedf aryl-sul~onylatod or aralkylsul~onylated by reacting with asul~onylating agent of tha formula GS0~-X

1 ~75819 wherein G is ~he lower alkyl group, the aryl group or the aralkyl group as de~ined hereinbe~ore and X is chlorine or bromine atom, in the reaction medium consi~ti~g of eg. dry pyridine. The sulfonylating agent GS02-X ma~ be an alkyl-~ulfonylating agent ~uch a~ methanesuleonyl chloride; an - arylsulfonylating agent suoh as p-toluene~ulfonyl chloride or an aralkylsulfonylating agent such as benzyl ulfonyl chloride or bromide. This sulfonylating step (e) gives the mono-sul~onylated product of which the 6~'-hydroxyl group alone ha~ been sulfonylated9 and/or the di-s~lfonylated product of which the 4"- and 6~'-hydroxyl group8 both have been sulfonylated. When the compound (V) is reacted with p-toluene~ul~onyl chloride ~in a substantially equimolar proportion) at ambient temperature~ the 6"-mono-0-tosylated product (corresponding to the compo~nd of the formula (V~) where the group GS03- is tosyloxy group p-CE~C6H4S03- and the group G' is the hydro~yl group) is produced as the main product in par~icular. On the other hand, ~hen the compound (V) is reaoted with methanesulfonyl chloride in a ~ub-~tantlally 2 molar proportions or more at ambient tem-perature, the 4",6"-di-0-mesylated product (corre~ponding to the compound o~ the ~ormula (V') where the group GSO~-and the group G' both are the mesyloxy group CH3S03~
produced in a favorable yield. ~hese 6"-mono~O tosylated product and 4",6"-di-0--me~ylated product both are the intermediate useful in this invention. G~nerally, the ~ulfonylation o~ the 4"- and 6'l-hydroxyl groups in the 1~7~9 above step ~8) may be effected at a temperature of 10 -to 100C and most pre-ferably at ambient temperature or at a temperat~rs o~ 10 to 60C and for a reaction time of ~0 mi~ute~ to 1 day.
The reaction mix-ture from the above sulfonylation step (e) i3 then admixed with a small volume of water to decompose the residual amount of the unreacted sulfonylation agent, ~ollowed by concentration to drynes~ under reduced pressure to give a crude residue compri~ing the sul~onylatio~
produc-t~ This residue is dissolved in a volume of chloro-~orm, and the resulting solution is washed with an aqueou~
potassium hydrogen sulfate~ with aqueous saturated ~odium hydrogen carbonate and with water. The chloroform phase is then dried with anhydrou~ sodium sulfate and then con centrated to dryness under reduced pressure to give a crude powder compri~ing the sul~onylation produc-ts. When thi~
crude powder is subjected to a column chromatography on ~ilica gel developed with a mi~ture of ~hloroform-ethanol, the 6"-mono-0-sulfonylated product and the 4",6"-di-0-sul~onylated product may be obtained separately.
In the next step (f) o~ the present process, the 6"-mono-0-sulfonylated product or the 4",6"-di-0-~ulfonylated product of the formula (V') i~ reacted with an alkali metal ~odide such a~ sodium iodide or an alkali metal bromide ~uch a~ ~odium bromide in an iner-t organic solvent such as dry dimethylformamide, dimethyl~ulfoxide, acetone 9 dio~ane and the like. The reaction may properly be e~fected at a ~ 1~581 reaction temperature o~ 50 to 150C and for a reaction time o~ 10 minutes to 1 day~ By thi~ reac-tion9 the 6"-mono-0-sulfonylated product is iodlnated or brominated to give the 6"-mono-iodo or bromo derivative or the 4",6"-di-iodo or bromo derivative.
In the further step (g) of the present process, the 6"-mono~halo derivative or the 4",6"~di-halo derivative obtained as above is reduced with hydrogen in a known marmer in the presence o~ a hydrogenolysi~ catalyst such a~ Raney nickelg palladium, platinum and the like and in solution in an inert organic solvent such a~ dioxane, methanol and the lik~ to e~fect the de-iodination or de-bromination. Thi~ de-iodinatio~ or de-bromination by hydrogenolysi~ may properly be effected at a temperature o~ from ambient temperature to 100C and for a reaction time of ~0 minutes to 24 hours under atmospheric pressure or even under an ele~ated pressure of 10 kg/cm2. This dehalogenation step (g) af-~ords the 6"-mono-deoxy derivative or the 4",6"-dideo~y derivative o~ the formula (V"). In thi~ way, the 6"-deoxygenation or the 4",6"~dideo~ygenation has been achieved.
In the last step (h) of the present process, the 6"
deoxy derivative or the 4",6"-di deox~ derivati~e (V") obtained in the above step ~g) is sub~ected to the treat-merlt ~or removal o~ the residual protective groups accordingto the corlventio~al deprotecting technique. ~he acyl group which ls present a~ the mono-valent hydroxyl-protecting ~75~9 group (D~E) may readily be removed by alkaline hydroly~i3 at ambient temperature, for example~ by treating with 12~o ammonia-methanol. ~en the amino-protecting group (B) is an aralkyloxycarbonyl group, thi~ type of the amina-protecting group is removed concurrently in the catalytic reduction step (g) o~ the present process, When the amino-protecting group (B) is o~ the kind other than the aralkyloxy-carbonyl group, the removal of such amino-protec~ing group may ea~ily be conducted in a kno~n manner, for example, by hydrolysis with a weak acid ~uch as a~ueous acetic acid~
In thi~ way, the desired product, that is, 6"-deo~ydibekaci~
(when R is hydro~yl grOllp in the ~ormula (I)~ or 4''v6''-dideo~ydibekacin (~Jhen R i~ a hydrogen atom in the -~ormula (I)).
Puri~ication o~ 6" deo~ydibekacin or 4",6"-dideoxy~
dibekacin so obtained may pre~erably be conducted by column chromatography on an cation-e~change resin containing ~arboxylic function~. To this end, it is recommendable to make the chromatographic purification by adsorption on Amberlite IRC 50 or CG-50 (NH4 form or a mi~ture o~ NH4 form and H ~orm) (a product of Rohm & Haas Co,, U.S.~) -~ollowed by elution with a dilute aqueous a~monia.
The new compound of the ~ormula (II) according to the aforesaid second aspect of thi~ invention includes l-N--(I-4~amino-2-hydroxybutyryl)-6" deoxydibekacin and l-N-(I~4-amino-2-hydroxybutyryl)-4",6"-dideoxydîbekacin.
These particular new compounds may be produced by acylation * trade mark . ' I .1 7S~lg of the l-amino group of 6"-deoxydibekacin or 4"96"-dideoxy-dibekacin with I~4-amino-2-hydroxylbutyryl group.
Aocording to the fifth a~pect of thi~ invention~
therefore, there i~ provided a proces~ for the production of 1~ 4-amino-2-hydroxybutyryl)-6"--deoxydibekacin or l-N~ 4-amino-2-hydroxybutyryl)-4",6"-dideoxydibekacin of the ~ormula (II) E2 ~ ~2/ =
0~

H~ ~H2 CO (II) CHOH
CH2CH2~I2 wherein R i~ a hydroxyl group or a hydrogen atom, which comprise~
(a3 acylating the l-amino group of 6"-deoxydibekacin or 4",6"-dideoxydibekacin or a partially amino-protected derlvative thereof repre~ented by the formula (I~) - 1 ~7~8 CH A
R ~ , / ~ \ >N

O

E2 N~B

wherein R is a hydroxyl group or a hydrogen atom9 and A is a hydrogen atom and at least one B i~ a mono-valent amino-protecting group but the other ~(s) lS or are each a hydroge~
atom~ or at least one pair o~ A and ~ taken together form a di-valent amino~protecting group 'DUt the other A and B
are each a hydroge~ atom, and the amino-protecting groups repre3ented by A and B may be equal to each other or di-~ferent ~rom each other, by reaction with an amino-protected derivative of ~-4-amino-2~hydroxybutyric acid or a ~unctional equi~al~nt thereto, to produce a l~N-acylated product o~
6"-deo~ydibekacin or 4't,6"~dideoxydibekacin repre~ented by the ~ormula (X) 1~7~19 CH

E2~ f------ Z 2 o~ OH o ~

CO (~) CHOH
CH2CE2NH~ ~ I

wherein Al is a hydrogen ato~ and ~' is a hydrogen atom or a mono-valent amino-protecting group, or A' and ~' taken together form a di-valent amino-protecting group~
or to produce an amino protected l-N-acylated product o~
6" deoxydibekacin or 4",6"-dideoxydibekacin repre~erlted by the formula ~X') 1 1 7~ 9 CH A

A \ ~ ~ ~ A
B / . OH OH
0, ~ ~ .

~ _ N <
CO
aXOH (X ' ) l~2CH2~ <
:B ' ~ .
: wherein R, A, ~9 A~ and ~' are as defined in the above ~ormula ~IX) or (~) 9 and (b) removing the rema-ining amino~protecting group(~) ~rom the l-N-acylated product of the formula (X) or ~X') i~
a kno~n manner, to produca the compound of the ~ormula (II).
The process oY the fifth aspect of thi~ inventio~
may include a ~urther step of converting the compound (II) into a pharmaceutically acceptable acid addition salt thereof by reacting with a pharmaceutically acceptable inorganic or organic acid in a known manner, if desirad.
~ he procedures ~or oarrylng out the process o~ the ~i~th a~pect o~ this in~ention are now described in more detailO
In aarrying out the present process, it is possible ~ 17~9 to employ as the star-ting material 6"-deoxydibekacin or 4",6"-dideoxydibekacin ~I) of which amino group~ are not protected at all, in the ~orm of the free acid or in the form of an acid addition salt with an appropriate acid ~uch a~ hydrochloric acid or sulfuric acid. However, it i~
preferable to employ a~ the ~tarting material ~uch a partially amino~protected derivative o~ 6"-deoxydibekacin or 4",6"-dideo~ydibekacin according to the ~ormula ~IX) in which all or ~ome o~ the amino groups other than the l-amino group ha~e been protected with known amino-protecting grOUp(6) and which may be prepared by intro-duction o~ a known amino-protecting group into the compound o~ the -~ormula (I) by means OI a known amino-protecting technique previously adop~ed in the synthesis o~ some ; 15 known deoxy derivatives of kan~mycin B. ~or the pre-paration of the partially amino-protected 6"-deoxydibekacin or 4",6"-dideo~ydibekacin derivative of the formula (IX)9 it is ~ea~ible to utilize the amino-protecting technique~
which were employed, for in~tance, in the preparation o~
the 6'-N-benzyloxycarbonyl derivative o~ kanamycin ~ a~
de~cribed in the ~peclfication of U.S. patent ~o. 3 9 781,268 or U.S. patent No~ 3,929,762; the preparation o~ 2',6'-di-N-tert-buto~ycarbonyl kanamycin B or 6'-N benzylo~ycarbonyl kanamycin B, or the mono-~ or di-~-tert-butoxycarbo~lyl and e~en tri-N-tert-butoxycarbonyl derirati~o of 6'-N-ben~ylo~ycarbony]-kanamycin ~, ei.ther i~olated or in mixture thereo~, a~ described in the speci~ication o~ U.E. patent ~ ~ 75~ g No 1,426,908 or ~.S. patent No. ~93g~l43; or the pre-paration of 2',3,3"~6'-tetra-N-formyl derivati~e of kanamycin B as described in the specification of Belgian patent ~o. 817J546.
In general, suitable examples of the amino-protecting group which may be used for the protection of some amino group~ of the compound o~ the general formula (I) as the initial material or may be present in the partiall~ amino-protected 6"-deo~ydibekacin or 4"96"-dideo~ydibekacin derivative o~ the ~ormula ~IX) may be an ordinary amino-protecting group, including an alko~ycarbonyl group ~uch as tert-butoxycarbonyl and tert-amylo~ycarbonyl; a cyclo-alkylo~ycarbon~l group such a~ cyclohexyloxycarbonyl; an aralkyloxycarbonyl group such as benzyloxycarbonyl; an acyl group ~uch a~ trifluoroacetyl and o~nitrophenoxyacetyl;
a phosphinothioyl group ~uch a~ diphenylpho~phinothioyl and dimethylphosphinothioyl; a phosphinyl group such as di-phenylphosphinyl, and the like. Preferred e~amples of the di-valent amino-protecting group include phthaloyl group and a group of Schiff base -type such as ~alicylidene.
~he introduction o~ the amino-protecting group o~ the~e kinds ~ay be conducted by reacting the compound o~ the ~ormula (I) with an appropriate known reagent for intro-duction o~ the amino-protecting group which may be in the ~orm of an acid halide, acid a~ide, active ester or acid anhydride and the like, in the manner known in the con-ventional synthesis of peptides. By chosing the quantity i ~l 75~19 of the reagent ~or introduction of the amino-protecting group employed in a proportion o~ 0.5 to 6 mol. per mol.
of the compound of the formula ~I), it is po~ible to prepare a mi~ture o~ di~fere~t, partially amino-protected derivative~ (IX) at any ratio, due to the di~`ference in the reacti~ity of the respective amino group8 of the compouna (I).
In the process of -the fifth aspect of thi~ in~ention, it i~ practical to employ as the starting material such an : 10 amino-protected 6"-deoxydibekacin or 4",6"-dideo~ydibekacin derivati~e in which all or some o~ the amino groups other than the l-amino group have or ha~ been blocked, ~or example, a 3,2',6l~3"-tetra-~-protected deri~ative t a 3,2i,6'-tri N-protected derivati~e9 a 2',6',3"-tri-N-pro-tected deri~ative, a 2',6' di-N-protected derivative and a 6'-mono-~-protected derivative. Be3ides, a mixture o~ two or more of these partially ~-protected deri~ative~ may, without being puri~ied, be used ~or the l-N-acylation step of the present proces3.
In order to ensure that the desired product o`f the ganeral ~ormula (II) can be produced in a high yield in accordance with the process o~ the ~i~th aspect in~ention, it needs only that ju~t the l-amino group of 6"-deo~y-dibe~acin or 4",6" dideoxydibe~acin is selectively aoylated with L-4-~a~ino 2-hydroxgbutgric acld. Accordingl~, it will be evident that mo~t pre~era~ly, a 3,2'96',3"-tetra-N-protected derivative o~ the compound (I), that is, the ami~o-protected derivative o~ the compound (I) in whioh ~758~9 all the amino groups other than the l-amino group have been blocked with the protective group~ i~ emp].oyed as the starting material to be l-N~acylated in the pre~ent proces~.
~o prepare the ~,2',6',3"-tetra-N-protected derivative of the ~ormula (IX) from the compound of the ~ormula (I), the following procedure may be used, for instance. ~hus, there can be applied a known method o~
U.~. patent ~o. 4,136,254 of ~agabhu~han et al by which a 3~2~,5'-tri-~ acylated protected derivative o~ kanamycin is ~repared by reacting kanamycin ~ with a di-valent transition metal cation9 ~or example~ cation o~ copper ~II), nic~el ~II), cobalt (II) etc. for the formation of a metal complex of kanar~cin ~, reacting thi~ kan~mycin ~-me~al comple~ with an acylation agent known a~ the amino protecting group-introducing reagent ~or the protec-tion of all the amino group~ other than the l-amino and 3"-amino group~ o~ the kanamycin ~ moiety ol the kanamycin ~-metal complex (said l- and 3"-amino group~ having been blocked by complexing with the di-valent metal cation in the kanamycin B-metal complex), and then remo~ing the di-valent metal ca-tion from ~aid complex, egO, by treat-ment with hydrogen ~ul~ide or by treatment with aqueou~
ammonia~ Or, -there oan be applied a method o~ our co-pending Japanese patent application No. 138402/78 (corresponding to our co-pending U.S. pa-tent application No 090,591; oo-pending U.E. patent application No.7938894;
,;

1~7~81g - ~9 -~elgian patent ~oO 879,925) by which a ~,2',6'-tri N
acylated protected derivative o~ kanamycin ~ is prepared in a ~imilar way to the aforeæaid known method of Nagabhushan et al except that ~inc cation i~ employed in stead of -the di-valent tran~ition metal cation. In thi~ way9 a 3,2',6'~tri-N-protected derivati~e of the formula (I2) can be prepared from the compound of the formula (I~ in a high yield. ~he 3"-amino group of thi~
3,2',6'-tri-N-protected deri~ative (IX) so prepared ca~
further be protected by the ~elective acylation according to a ~elective 3"-~-acylation method of our co-pending Japan~se patent application NoO 7~064/79 (~ee claim 15 o~
said Belgian patent No. 879,923) for the production of an amino-protected derivative o2 an aminoglycosidic anti-biotic of which all the amino group9 other than the l-amino group have been protected selectively, ~o that a 312',6',3"-tetra-N-protected derivative o~ the compound (I) can be prepared in a high yield. In accordance with the ~elective ~"-N-acylation method of the co-pending Japane~e patent application No. 73064/79 (as described in the claim 15 of the ~elgian patent No. 879,923), the above-mentioned 3,2',6'-tri-~-protected derivative o~ the compound (I) i~ reacted with a ~ormic acid alkyl e~ter, a di-halo or tri-halo-alkanoic acid alkyl e~ter, formyl~midazole or an N-alkanoyl-imidazole a~ the acylation agent, whereby the 3"-amino group can be acylated ~electively with the acyl re~idue of the acylation agent employed in a high yield, without , .

8 1 g - ~o -involving the acylation of the l-amino group of said 3,2',6'-tri-N-protected deriv~tive. The ~ 9 2',6'93"-tetra ~-acylated derivative~ for e~ample, 3,2',6'-tri-N~benzylo~ycarbonyl~ N-tri-fluoroacetyl deri~ative, o~
6"-deoxydibekacin or 4",6'1-dideoxydibekacin which may be obtained by applying the above-mentioned method~ of the .S. patent ~oO 4 91~6, 254 and of the ~elgian patent ~o. 879,923 is a most preferred material to be 1-~-acylated selectively with the ~-4-amino-2-hydro~ybutyric acid in the l-N-acylation step of the present process.
In the proces~ of this fifth a~pect in~entio~5 the l-amino group o~ the compound of the formula (I) or the l-amino group of the partially amino-protected deri~ative~ (IX) thereo~, either isolated or in mi~tura ~ two or more of them, i~ acylated with ~-4-amino-2-hydro~ybutyric acid of which the amino group i3 not protected or has been protected. This l-N-acylation may be conducted according to any of the co~ventional methods for the ~ynthe~is of peptides, for instance~ according to the known dicyclohaxylcarbodiimide method, the known mixed acid anhydride method, the known a~ide method or the active e~ter method and the like, u~ing I-4-amino-2-hydroxybutyric acid a~ such or in the f`orm of its reaotiva derivative ~as the functional equivalent thereo~). Ae the amino-protecting group ~or protection o~ the amino group of X~-amino-2-hydro~ybutyri.c acid ma~ be employed such an amino-protecting group which i~ the ~ame as or di~erent 3~75~1g ~rom the one pre~ent in the compound (Ig~. Particularly~
a preferred amino-protecting group for thi~ p~rpose i~
tert-butoxycarbonyl group which is easily removable by treatment with aqueou~ trifluoroacetic acid or acetic acid or with diluted aqueou~ hydrochloric acid. Benzyloxy-carbonyl group ~hich i~ r~ovable by a conventional hydro~
genolysis in the pre~ence of a catalyst such as palladium or platinum o~ide i~ a convenient ~-protecting group.
The 1 N-acylation in the present pro~ess may pre ~erably be carried out in an aqueous organic solvent according to the active e~ter method u~ing I-4-amino-2-hydroxybutyric acid in the form of it~ active e~ter.
For example, ~--hydro~ysuccinimide e~er of ~-4 benzylo~y-carbonylamino-2-hydro~ybutyric acid may preferably be u~ed a~ the active e~t~r which may be prepared by a conventional method of preparing the active e~ter. Thi~ active e~ter pre~erably may be u~ed in a proportion of from 005 to 3 molar equivalents and pre~erably o~ from l to 1.5 molar equivalents per mol of the 6"-deoxydibekacin or 4"~6"-dideo2ydibekacin compound to be l-N-acylated. The aqueou~
organic ~olvent u~ed in the reaction medium may be a water-mi~cible organic ~olvent ~uch a~ dioxane, lt2-dimetho~y-ethane, dimethyl~ormamlde, tetrahydrofuran, and the like.
The l-N~acylation may be e~ected at ambient temperature or, lf de~ired, at an elevated temperature of 20~90C and for a reaction time o~ ~everal hour~ and preferably o~

5~6 hour~.

1~5 When the l-N-acyla-tion in the present proces~ i3 conducted using as the starting material such a partially amino pro~ected derivative in which ~ome9 but not allg of the amino groups other than the l-amino group has or have bee~ protec~ed, for e~ample, the 6'-N-protected derivative of ~"-deoxydibekacin or 4"96"-dideo~ydibekacin, the acylation products a~ ~ormed may partially be purified by a column chromatography, for example, on silica gel so that the ~n-reacted ~-ta~ting material is removed, giving a mixture o~
the de~ired l-N-mono-acylated product with the otherwise N-acylated products, as the case be in the synthesi~ of 4-amino-2-hydro~ybutyryl)-3',4'-dideoxykanamycin ~ as described in the specification of U.3. patant No~4~107,4240 : These miged acylation products may, without being purified and/or i~olated, be sub~ected immediatelg to the sub~e-~uent de-protecting ~tep of the present process, followed by the purification and isolation so that the desired l-N-mono-acylated produc-t is obtained.
In the second step of the proce~s of this fifth a~peot invention, the l-N-acylatioll product (including the mixed acglation product~) a~ obtained in the 1-~-acylation step of the present proces~ is sub~ected to the remo~al of the ami~o-protecting groups, if thesa are still remai~ing i~ the l-N-acylation product. The removal of the protectlng groups i8 effected by a conventional de-protecting technique Thus, the amino-protecting group of the alkoxycarbonyl type i8 removed by weak acid hydroly~i~ using an aqueous solution of trifluorcacetic acid or acetic acid and the like or a diluted aqueou~
solution of a~ inorganic acid such as hydrochloric acid The aral~ylo2ycarbonyl gro~ such as benzyloxycarbonyl may be removed by an ordinary catalytic reduction (hydro-genolysis). When phthaloyl group is present as the ~mino~
protecting group~ it can be removed by heating in a solutio~
o~ hydra~ine hydrate in a lvwer alkanol.
The deprotected acylation product as obtained from the ~econd, de-protec~ing step of the present process may contain comprise the desired l-N-acylation product o~ the formula ~II) together with some i~omers thereofO The de~ired 1~ 4-amino-2-hydro~ybutyryl) derivative (II) may be isolated and purified chromatographically using a cation exchanger conta~ning carboxylic ~unctions, such as Amberlite CG-50 (a product o~ Rohm & Haas Co., U.S.A.) or CM-Sephadex C-25 (a product of Pharmacia Co. 9 Sweden) and as~aying the antlbacterial activity of the fraction~ of the eluate by means o~ a proper kanamycin-sensitive strain and kanamycin-resistant strain o~ bacteria.
Besides, the new compound o~ the ~ormula (II) according to the second aspect of this invention may also be prepared starting from the known compound, 1-N-(I-4-amino-2-hydroxybutyryl)-3',4'-dideo~ykanamycin B~ that is, 1~ 4 amino-2-hgdro2ybutyryl)-dibekacln. According to the sixth aspect o~ this invention, therefore, there i~
provided a process ~or the production of l-N-(I-4-amino-* trade mark 3 17~9 2-hydro~ybutyryl) 6"-deoxydibekacin or -4",6"-dideoxy-dibe~acin of the formula (II) X ~ f7 ;;~Z~I2 ~

H~ E2 CO
I (II) CHOE
CH2~E2~H2 wherein R i3 a hydro~yl. group or a hydrogen atom, which comprise~
(a) protecting with a known amino-protecting group the fi~e amino group~ of l-N~ 4-amino-2-hydroxybutyryl)-dibekacin of the ~ormula (VI) 3 ~7~9 HO ~

2 OH O~ O
O ~

HN ~ NH2 (YI) CO
CHOH
CH2 CHz~I2 ln a known manner to produce an amino-protected derivative of the formula (VI') HO ~ A

A ~ ~
B OH ~ A

7 N < (YI ?
ao CHOE
CH2CH2<~

3 1 7~8~ 9 - 46 ;

wherein A i~ a hydrogen atom and ~ i~ a mono-valent ~miho-protecting group9 or A and ~ taken together ~orm a di~valent amino-protecting group9 (b) protecting with a known di-valent hydroxyl-: 5 protecting group simultaneously the 4"- and 6"-hydroxyl group~ of the amino-protected derivative ~VI') in a know~
. manner to produce a protected derivative of the ~ormula (VI") ~`C'O ~ A> ~ 7 < A

~>~ OH
~ ~ VI") HN ~ ~ ~
I .
CO
C~OH
i A
CH2CH2N~ E3 wherein A and ~ ha~e the ~ame meaning~ a~ defined above and the group of the ~ormula X ~ ~ i9 a di-valent y~ ~
hydrox~l-protocting group where X an~ Y are each a hydrogen atom, an a~kyl groupt an aryl group, or an alkoxy group, or the group of the formula X~ / is a cycloalkylidene group, Y / ~

~ ,1 7~8~'g ~ 47 -(c) protecting with a known mono-valent hydroxyl~
protecting group either the two, 2"- and 2"'-hydro~yl groups or the three, 5-, 2"- and 2"Lhydroxyl groups of said pro-tected derivative tVI") in a known manner to produce an amino-protected and hydro~yl-protected derivative o~ the ~ormula (VII) A ~ ~ < B

N<
ao 2"' CHOD . (VII) I A
CH2CH2N<

wherein A, ~ and the group of the formula ~C ~ have the ~ame meanings a~ defined above, D is a mono-valent hydroxyl protecting group in the form of an acyl group, and E i~ a hydrogen atom or a mono-valent hydroxyl-protecting group in the ~orm of an acyl group~
(d) removing the group ~ ~C~ ) of protecting the 4"~ and 6"-hydro~yl groups of said amino-protected and hydro~yl-protected derivative (VXI) therefrom in a known manner to produce a partially pro-tected compound ~7 o~ the formula (VIII) ~O ~ A
~ O\ / N ~ ~ < A

A ~ ~ O
B OD O~ o 0 ~

H~_ <~
CO
CHOD (VIII) - CE2CH~<

~herein A, ~ D and ~ have the same meanings a~ defined abo~e, (e) sul~onylating with a sulfonylation agent the

6"-hydroxyl group alone or ~imultaneou~ly both the 411_ a~d 6"~-hydroxyl group~ o-~ ~aid partially protected com-pound (VIII) in a known manner to produce a mono-~ulfonylated or di-~ulfonylated derivative o~ the ~ormula (VIIX') 1 ~75819 GSO3 ~

OD~ _ Y

<
CO
I (VIII') GHOD
CH2CH2N<

: . .

wherein A, B, D and E have the same meaningæ a~ defined abo~e, G is a lower alkyl group o~ 1-4 carbon atoms, an aryl group such a~ phenyl or p--methylphenyl, or an aralkyl 5 group such as benzyl~ and G' is a hydro~yl group or is the ~ame as the group GSU3- shown in the formula (VIII'~, (~) reacting the 6'l-mono-sulfonylated or 4",6"-di-sul~onylated derivative (VIII') with an alkali metal iodide or bromide in a known manner to replace the 6"-~ul~onylox~
10 group or the 4"- and 6"-sulfonyloxy groups by io~o or bromo group, respeo~iv01y, and thereby to produce the corresponding 6"-mono-iodo or brvmo derivative or the corresponding 4",6"-di-iodo or bromo derivative, (g) reduci~ ~aid 6"-mono-iodo or bromo derivative or said 4",6"-di-iodo or bromo der.ivative with hydrogen J .~ 7581g - 50 ~

in the presence of a hydrogenolysis cataly~t to effect the dehaloge~ation and thereby to produce the corresponding 6"-mono-deoxy derivative (which is corresponding to ~uch a compound of the formula (~III') but where the group GS03-has been converted into a hydrogen atom and G' i~ remaininga~ the hydro~yl group~ or the corresponding 4"76"-did00~y deri~ative (which i~ corresponding to such a compound of the formula (VIII') but ~here the group GSO~- and the Group G' each ha~e been convertea into a hydrogen atom~
represented by the formula (VIII") c~3 R \B ~ ~ ~ < A
A ~ ~ ~ ~ B
OD 0~ 0 o~,~_ . ~ \ < A
bo B
CHOD (VIII") I A
CH2CH2N<

wherei~ A, ~7 D and E are as defined above and R i~ a hydro~gl group or a hydrogen atom, and (h) removing the remaining amino-protecting group~
and the remaining hydroxyl-protecting group~ from the 6"-mono-deoxy derivative or 4t',6"-di-deoxy derivative (VIïI") I ~7~19 in a known manner to produce l~ 4-amino-2 hydroxybutyryl)-6"-deo~y or -4~',6~-dideoxydibekacin o~ the ~ormula (Il).
The proce~ of the above-mentioned sixth aspect o~
thi~ inven-tion mayp if necessary9 include a furthsr ~tep of converting the compound o~ the formula (II) into a pharma-ceutically acceptable acid addition salt thereof by reacting with a pharmaceutically acceptable inorganic or or~anic acid in a known manner ~he step~ (a~ to (h) of the proces~ of the ~i~th aspect invention may be carried out in the same manner as hereinbefore describea in respect o~ the ~tep~ (a) to (h) of the proce~ o~ ~he aforesaid fourth aspect in~ention, re~pectively. Accordingly, the description~ of the procedure~
for carrying out the respective steps of the proce~ of the ~i~th aspect invention are omitted here.
~ his invention is now illustrated with reference to the following Examples to which this in~ention is not limited~
E~amples 1 and 2 are illustrative of the first and fourth aspects of this in~ention, E~amples 4 and 5 are illu~trati~e of the ~econd and fi~th aspects of this invention~ ~nd Ex~mpla 3 i~ illustrati~a o~ the si~th aspect of thi~
invention.
~e~
(a) Synthe~is o~ 2"-0-benzoyl-1J3,2',6',3"-penta-N--tert-butoxycarbonyl~dibekacin Dibekacin ~3.0 g, 6.65 m mol) wa~ di~solved in 10 m~
of water, and the resulting so.Lutio~ was admixed with 4.63 ~Q (33.24 m mol) of triethylamine and 30 mQ of methanolO To the admixture was dropwise added a solution of 11.5 g (50 m mol) of tert-butyl S-4,6-dimethylpyrimid-2-ylthiocarbona-te in 20 mQ
of methanol, followed by stirring at 60C for 5 hours -to effect the reaction of introducing the tert-butoxycarbonyl group as the N-protecting group into the starting dibekacin. The reaction solution was concentrated under reduced pressure to about a half volume and then poured into 650 mQ of water, followed by standing overnight in a refrigerator. The precipitate formed was removed by iltration and washed with 300 mQ of water and with 150 mQ of ethyl ether to give 4.73 g (yield 75%) of a faintly brown powder of l,3,2',6',3"-penta-N-tert-hutoxycarbonyl-dibekacin.
This powder (1.0 g, 1.05 m mol) was dissolved in 21 mQ
of anhydrous dimethylformamide, and the resultant solution was further admixed with 432 mg (3 m mol) of l,l-dimethoxycyclo-hexane and 42 mg (0.24 m mol~ of p-toluene-sulfonic acid, followed ; by stirring at ambient temperature for 16 hours to effect the reaction of introducing the 4",6"-0-cyclohexylident group. The reaction solution was admixed with 0.1 mQ of triethylamine and then concentrated to dryness under reduced pressure. The residue was taken up in 100 mR of chloroform and the solution obtained was ; washed with the equal volume of water and dried on anhydrous sodium sulfate, followed by concentration under reduced pressure, affording 1.10 g (yield 100%) of a faintly yellow pow~er of 1,3,2',6',3"-penta-N tert-3 ~75819 -- 53 ~

butoxycarbonyl~4" 9 6"-0-cyclohe~ylidene~dibekacinO
~ hi~ powder ~800 mg~ 00775 m mol) wa~ dis~ol~ed in 16 m~ of dry pyridine, and the solution was admixed with 260 mg (1.86 m mol) of benzoyl chlori.de, ~ollowed by stirring at 60C overnight to effect the reaction o~
introducing the 2"-0-benzoy~ group. The reaction 901ution wa~ admi~ed with 1 mæ of methanol to decompose the e~cesJ
of the benæoyl chlorida unreacted. ~he reaction solution wa~ then concentrated to a æmaller volume under reduced pre~ure to give an oilO ~hi~ oil wa~ taken up in 50 m~
o~ chloroform, and the resulting solution was washed with the ~ame volume o~ 5~o aqueous potassium hydrogen sul~ate~
then with the same volume of ~aturated aqueou~ ~odium hydrogen carbonate, and finall~ with the ~ame volume of water~ The ~olution in chloro~orm wa~ separated, dehydratea on anhydrous sodium ~ul~ate and co~centratea under reduced pre~sur~0 ~he residue was washed with small volumes o~
chloroform and n-hexane, giving 826 mg (yield 94~) o~ a ~aintly ~ellew powder of 2"rO-benzoyl-1,3j2',6',3"-penta-N~tert-buto~ycarbo~yl-4",6"-0-cyclohegylidene-dibeka~in.
This powder (815 mg~ 0.718 m mol) was dis~olved in 20 m~ o~ a mi~ture of acetio acid7 methanol and water (2:1:1 by volume), and the resulting solution was stirred at 50C ~or 1 hour and at 40-C ~or ~ hours to e~ect the hydrol~tic removal o~ the 4~,6~-0-cyclohe~lidene group4 ~he reaction solu-tion wa~ concentrated under reduced pre~re and the re~idue was taken up in 50 m~ o~

~ ~7$8~9 chloro~orm. The ~ol.ution was ~ashed with the same volume of aqueous saturated sodium hydrogen carbonate and with the same volume of water, followed by dehydratio~ of the chloro~orm pha~e on anhydrou~ oodium sulfate and con~
centration of the solution in chloroform to dryness under reduced pressure to glve 758 mg (yield 100%~ o~ a falntly yellow powdsr o~ 2"-0-benzoyl-1,3,2' 9 6',3"-penta-~ tert-buto~ycarbonyl-d~bekacin (b~ Synthe~is of 4"96i'-dideo~ydibekaci~
The 2'~ 0-benzoyl-1~3~2',6' 9 3"~penta-~-tert buto~y-carbonyl-dibekacin (850 mg, 0.805 m mol) obtained in the above procedure of E~ample l(a) was dissol~ed in 20 m~ of anhydrou~ pyridine, followed by addition o~ 483 mg (4~24 m mol) of mesyl chloride thereto and reaction of the ra-sulting admixture at 40-50 a overnight to ef~ect the mesylationO ~he reaction mixture was admixed with a small volume of water for decomposition o~ the unreacted mesyl chloride, followed by concentration to dryness under reduced pre~sure. ~he residue was taken up in 100 m~ of chloroform and the solution obtained wa~ washed ~7ith the same volume o-f 5% aqueou3 potassium hydrogen sulfate, with the aame volume o-f aqueous saturated sodium hydrogen carbo-~ate and with th.e same volume o~ water, and the chloro~o~m phase was d~hydrated on anhydrous sodium sulfata and con-centrated to dryness under reduced pressure to a~-ford a lightly brown powder o~ 2"-0-benzoyl-1,3,2'~6',3"-penta-~-tert-butoxycarbonyl-4",6"-di-0-mesyl-dibekacin. ~his I ~ 7581 9 crude powdar was purified by a colum~ chromatography on silica gel (100 g9 Wako Gel C~100, a product of Wako Junyaku Co., Japan~ developed with a mixture of chloro-~orm and ethanol (100:1 by volume) to gi~e 859 ~g (yield 88%) of a puri~ied colorles~ powder~
This colorless powder (350 mg, 0.289 m mol) was dissol~ed in 7 m~ o~ anhydrous dimeth~lformamide9 and the resulting solution was admi~ed with a large exces~ ~3.5 g) o~ sodium iodide~ followed by ~tirring at 95 C for 5 hours under argon atmosphere to effect the 4"96"-di-iodinat~onO
The reaction ~olution was admixed with 50 mQ of water, and the precipitate formed was removed by filtration a~d washed with water~ The precipitate collected was dissolved in 50 m~ of chloroform~ and the solution wa~ washed with the same volume of 20% aqueou~ sodium thiosulfate and then with the same volume of water. ~he chloro~orm pha~e was dehydrated on anhydrous sodium sul~ate and concentrated to dryness under reduced pressure, giving a colorless powder (~59 mg). This powder was purified by a chromatograph~
on thin layer of ~ilica gel (Silica Gel ~ 500t K~ plate, a produrt o~ Camag AG., Swis~) developed with a mixture o~
chloroform and ethanol (20:1 by volums), when the product pre~ent in the region o~ the silica gel thin layer cor~e-sponding to R~ 0.6 was colleoted. A colorless powder (210 mg, yield 57%) of 2"-0-benzoyl-1~3,2',6',3"-penta-N-tert-butoxyoarbonyl-4",6"-di-iodo-dibekacin was afforded.
Thi~ colorless powder (210 mg) was dissolved in * trade mark 1 ~7~9 5 m~ of dioxane~ and the solution was admixed with 50 mg of Raney nickel catalyst (R-200~ a product o~ ~ikko Rika CoO, Japan) and was subjected to the catalytic hydrogenoly~
~i~ with h~drogen at a hydrogen pressure of 3,6 Kg/cm2 in a Parr apparatus overnight at ambient temperature to effect the de-iodination. The reaction mi~ture was filtered to remove the catalyst there~rom, and the filtrate was con-centrated to dryness under reduced pressure. ~he residue was dissolved in 5 mQ o~ 12% ammonia~methanol and the solution was allowed to stand o~ernight to e~ect the debenzo~lation~ The reaction solution was then con-cen-trated under reduced pressure, and the solid residue wa~ taken up in 20 m~ of chloroform~ followed by washing with water. The solution in chloroform was then dried on anhydrou~ sodium sulfate and concentrated to dryness under reduced pressure, ~ielding a colorless powder. This powder was dissolved in 2 m~ of a ~olution of 90~ tri~luoroacetic acid in water and the~ allowed to stand at ambient tem-perature for 45 minutes to ef~ect the removal of the tert~
butoxgcarbonyl groups. The reaction ~olution was again co~centrated under reduced pressure and the re~idue wa~
wa~hed with a ~olume of e~hyl ether to give a faintly yellow powder (comprising the tri~luoroacetate o~ the desired 4",6'l-dideoxydibekacin). ~his powder was taken up in a volume o~ water and passed through a column of 17 mQ of Amberlite CG-50 (NH~+) ~or adsorption of the de~ired product. The Amberlite column wa~ washed with ~ ~ 7 water and then eluted with 0 4M aqueous ammonia. The biologically active eluate was collected and concentrated to dryness under reduced pressure to afford 36 mg of a colorles~ powder o~ the desired 4",6"-dideo~ydibekacin in the ~orm of its sesqui-carbonate. Yield 52~. Thîs powder decomposed slowly at about 129C and gave a specific optical rotation ~]2~ = + 126 (c 0,5~ water).
~2a~
Synthesis of 6"-deoxydibekacin The 2"-0-ben~oyl-1,3,2',6'~3"-penta-~-tert-buto2y-car~o~yl-dibekacin ~500 mg, 0.473 m mol) obtained ~n the procedure o~ ~xample l(a) wa~ dis~olved in 10 m~ of an-hydrous pyridine, and the resulting solution was aam~xed with 130 mg (1.14 m ~ol) of mesyl chloride. The admixture was ~tirred at 30C overnight to ef~ect the mesylat~on.
The reaction solution was admixed wlth a small volume o~
water, followed by standing for 30 minutes at ~mbient temperature to decompose the unreacted mesyl chloride.
The reaction solution was concentrated to dryness ~der reduced pressure, and the residue was di~solved in 50 mQ
o~ chloro~orm. ~he solution in chloro~orm was washed with the ~ame volume of 5% aqueous potassium hydrogen sulfate, with the ~ame volume of aqueous saturated sodium hydrogen carbonate and then with the ~ame volume of water. The chloro~orm pha~e was dried on anhydrous ~odium sul~ate and concentrated to dryne~s under reduced pre~sure to give a lightly brown powder. This powder was purified ~758~9 by a column chromatography on silica gel (Wako Gel C-200, a product o~ Wako Junyaku CoO, Japa~) developed with a mi~ture o~ chloro~orm and ethanol (50:1 by volume) to give 114 mg (yield 20~o) of a colorless powder of 2"~0-benzogl~
1,3,2',G',~"-penta-N-tert-butoxycarbonyl-4",6"-di-0-mesyl~
dibekacin and 250 mg (yield 47~) of a colorless powder of 2"-O-benzoyl-1,3,2'~6'j3'l-penta-N-tert-buto~ycarbonyl-6"-0-mesyl-dibekacin.
The colorless powder (39 mg, 0.0344 m mol) of the latter, that is, the 6"-0-mesylated product was dis~olved in 1 m~ o~ anhydrou~ dimethylformamide, and the resultant solution was admixed with 390 mg (2,6 m mol) of sodium iodide, ~ollowed by agitating the admixture at 90C for 2 hours to effect the 6"-iodinationO The reaction solution was admixed with 30 m~ of chloroform, and the ~olution obtained wa~ washed with three 30 m~-portions of aqueous ~aturated sodium chloride~ with 30 m~ o~ aqueous 20~ sodium thiosul~ate and then with 30 m~ of water. ~he chloroform pha~e was dried on anhydrou~ sodium sulfate and concentrated to dryness under reduced pressure, giving 38 mg of a color-less powder of 2"-0-ben~oyl-1,3p2',6',3"-penta-N-tert-butoxycarbonyl-6"-iodo-dibekacin.
~hi~ powder wa~ dissol~ed in 1.5 m~ of dioxane and the solution was admixed with 20 mg of Raney nickel catalyst (R-200, a product of ~ikko Rika Co., Japan) and then sub-jected to a catalytic hydrogenolysis at a hydrogen pressure of 3.6 ~g/cm2 *or 24 hours in a Paar apparatus to effect the de~iodinationO The reaction mi~tu~e was filtered to remove the catalyst there~rom, and the filtrate was con-centrated to dryness under reduced pressure~ The residue was taken up in 2 m~ of a solution of 12~ ammonia in methanol. The resulting solution was allowed to ~tand at ambient temperature overnight to effect the de~benzoyla-tion. The reaction solution was concentrated to dryness under reduced pressure to a~ford a colorless powder. ~his powder wa~ dissolved in 1 mQ o~ aqueou~ 90~ tri*luoroacetic acid, followed by standing at ambient temperature ~or 45 mi~utes to e~fect the removal o~ the tert-butogycarbonyl groups. The reaction solution was concentrated to dryness under reduced pressurei and the residue was wa~hed ~ith a volume o~ ethyl ether to give a faintly yellow powder (comprising the trifluoroacetate of the desired 6"~deoxy-dibekacin). This powder was dissolved in water ancl the aqueous solution was passed through a column of 5 m~ of Amberlite CG~50 (~E4~ ~or adsorption of the desired product. The Amberlite column was washed with water and then eluted with 004M aqueou~ ammonia. The active eluate wa~ collected and concentrated to dryness under reduced pre~ure to give 12 ~g of a colorle~ powder of 6"-deo~y-dibekacin in the form of it~ ~esqui-carbona-te. The ~ield was amounting to 75% as calcula-ted from the intermediate 6"-0-mesylated product mentioned hereinbe~ore. This 6"-deogydibekacin sesqui~carbonate decomposed slowly at about 1~1C and gave a specific optical rotation [a]D6 = ~ 101-~75819 _ 60 --(c 0044, water).

(a) Synthesis of 2"92"'-di-0-benzoyl-3,2',6'73",4"9-penta-N-tert-buto~ycarbonyl-l NA (I-4-amino 2 hydro~ybutyryl)-dibekacin l-N~ 4-Amlno--2-hydroxybutyryl)~dibekacin (679 mg~, 1.23 m mol) wa~ dissolved in 14 m~ of aqueous 50% dio~ane9 and to the re3ulting solution was added 1 m~ ~7.2 m mol) of triethylamine and then dropwise a ~olution of 2.96 g (12.3 m mol) of tert-butyl S-4,6-dimethylp~rimid-2-ylthlocarbonate in 7 m~ of dioxane ~he admi~ture obtained was ~tirred at ambient temperature for 40 hours to e~fect the ~-tert-butoxycarbonylation, followed by concentration of the reaction solution to dryness under reduced pressure. The re~idue was washed with 100 m~ portions of n-hexane and water, a~fording 1.0 g ~yield 82~) of a faintly yellow powder of 3,2' 9 6' 9 ~1; 4"'-penta-N-tert-buto2ycarbo~yl-l-N-(I-4-amino-2-hydro~ybutyryl)-dibekacin.
This powder (1.0 gO~ 1 01 m mol) was ta~en up in 20 mb of anhydrous dimethylformamide, and the ~olution obtained wa~ admixed with 4 mg of p-toluene~ulfonic ac~d a~ld 0.5 m~ (4.1 m moL) of 2,2-dimetho~ypropanel fol:Lowed by ~tirrin~ the admlxture at ambient temperature for 17 hours to effect the 4",6"-0~ opropylidenation. The re~
action solution, after addition of one drop of triethyl-amine thereto, was concentrated to dryness under reduced pre~sure, and the re~idue wa~ dissolved in 150 m~ of 1~7~19 ehloroformO The solution in chloroform was then washed with two lO0 m~ portion~ of aqueous satura-ted sodium hydrogen carbonate and then with lO0 m~ o~ aqueous saturated ~odium chloride~ and the chloroform phase was subsequently dried on anhydrous sodium sulfate and concentrated to drynes~ to give l.l g of a lightly yellow crude powder of 3,2' 7 6',3",4"1-penta-N-t ert-butoxycarbon~l-4",6"-0-isopropylidene-l-N~ 4-amino-2-hydroxybu-t~ryl)-d ibekac in.
This powder was dissolved in 30 m~ of chloroform and purifiea chromatographically in a column of silica gel (100 g., Wako Gel C~200, a product of Wako Junyaku COr ~
Japan) de~eloped with a mi~ture of chloro~orm and ethanol (20:1 by ~olume). The fractions of the eluate which con~
talned the desired product were concentrated to dryne3s under reduced pressure to afford 842 mg of a purified colorless powder of the desired product (yield 77~).
This powder (840 mg, 0.78 m mol) was dissolved in 10 m~ of anhydrous pyridine to which was then addecL 0O4 m~
(3.4 m mol) of benzoyl chloride. The resulting solution wa~ ~tirred at ambient temperature for l8 hour~ to`e~ect the 2",2"'-di-0 benzoylation. The reaction solution wa~
admixed with one drop o~ water to decompose the un~eacted, exces~ive benzoyl chloride, and the reaction solution was -then concentrated to dryness under reduced pressure. The residue wa~ taken up in lO0 m~ of chloroform and the ~olution wa~ washed with lO0 m~ of 0.25N hydrochloric acid, with three 50 m~ portion~ o~ aqueou~ saturated sodium 1J175~19 hydrogen carbonate and then with 100 m~ of aqueou~ ~aturated ~odium chloride. The ~olution in chloroform wa~ dried on anhydrous sodium sul~ate and concentrated to drynes~ under reduced pres~ure to a~ford 1.017 g (yield 100%) of a faintly yellow powder of 2",2"'-di-0-benzoyl 3,2'~6'~3'`,4"'-penta-N-tert-buto~ycarbonyl-4"96"-0-i~opropylidene-l-N-(I-4-amino-2-hydroxybutyryl)-dibekacin.
Thi~ powder (975 mg9 0.76 m mol) was dissolved in 20 m~ of a mixture of acetic acid, methanol and water (2:1:1 by volume) and the resulting solution was agitated at ambient temperature for 15 hours to ef~ect the de-i~opropylidenation, and the reaotion solution was con-centrated to dryne~s under reduced pressure. The re~idue wa~ dis~ol~ed in 100 m~ of chloro~orm and the solution wa~ wa~hed with two 100 m~ portion~ of aqueous saturated sodium hydrogen carbonate and then with 100 m~ o~ aqusou~
saturated sodium chloride. ~he chloro~orm phase (the solution) wa~ dehydrated with anhydrous sodium sul~ate and then concentrated to dryness under reduced pressure to give 873 mg (yield 93%) of a faintly yellow powder o~
2l',2"'-di-0-benzoyl-3,2',6',3",4"'-penta-N-tert-butoxy-carbonyl-1-~-(1-4-amino-2-hydroxybutyryl)-dibekacin~
(b) Synthe31~ o~ 1-N~ 4-amino-2-hydro~ybutyryl)-4",6'1-dideoxydibekac in and 1-N-(L-4-amino-2-hydroxybutyryl)-6"-deoxydibekacin 2",2"'-Di-0-benzoyl-3,2',6',3",4"' -penta-N-tert-butoxycarbonyl-l-N-(L-4-amino-2-hydroxybutyryl)-dibekacin ~ ~75819 6~ -(250 mg, 0~2 m mol) obtained in the .E~ample 3(a) was dissolved in 5 m~ of anhydrous pyridine, and the resulting solution, after addition of 0.06 m~ 3 m mol) of mesyl chloride thereto, was agitated at ambient temperature for 16 hour~ to effect the mesylation. To the reaction solution was added one drop of water to decompose the unreacted~ excessive mesyl chloride. The reaction solution wa~ then concentrated to dryness under reduced pressure and the residue was dissolved in 25 m~ of chloro~orm. The solution obtained was washed with 25 m~ of 0~2N hyclrochloric acid, with three 25 mQ portions of aqueous saturated sodium hydrogen carbonate and then with 25 m~ of aqueou~ ~aturated qodium chlorîde, and subsequently the solution in chloro- i form was dried on anhydrous sodium sulfate, ~ollowed by concentration to dryness under reduced pres~qure, giving 271 mg (yield 96%) of a lightly brown powder comprising 2"~2"'-di-0-ben~oyl-392',6',~",4"'-penta-N-tert-buto~y-carbonyl-4",6"-di-0-mesyl-1-N-(I~4-amino-2-hydroxybutyryl) dibekacin (which gave a single spot at Rf 0.25 in a silica gel thin layer chromatography developed with chloroform-methanol (30:1)) and a minor proportion o~ 2",2"'-di-0-benzoyl-3,2'~6',3",4"'~penta-N-tert-buto~ycarbonyl-6"~0-mesyl-l-N~ 4 amino-2-hydroxybutyryl)-dibekacin (which gave a single spot at Rf 0.18 :Ln the same silica gel thin layer chromatography ~ust mentioned above).
Thi~ powder (2~0 mg, 0.155 m mol) was dissolved in 4.4 m~ of dry dimethyl~ormamide7 and the ~olution was 3 ~1 75~1 ~

admixed with a large excess (2.3 g) of sodium iodide, followed by agitation at 90 C for 6 hours to effect the substitutive iodination. The reaction solution was admixed with 50 mQ of water and the precipitate as formed was removed by filtration.
The precipitate collected was dissolved in 20 mQ of chloroform and the solution was washed with two 20 mQ portions of aqueuos 20g6 sodium thio~ulfate and then with 20 mQ o~ aqueous saturated sodium chloride. The solution in chloroform was dried on anhydrous sodium sul~ate and concentrated to dryness under reduced pressure to give 224 mg (yield 99~6) of a colorless powder comprising a main proportion of 2",2"'-di-O~benzoyl-3,2',6',3",4"'-penta-N-tert-butoxyearbonyl-4",6"-di-iodo-l-N-(L-4-amino-2-hydroxybutyryl) -dibekacin (which gave a single spot at Rf 0.40 in a silica gel thin layer ehromatography developed with chloroform-ethanol (30:1) and a minor proportion of the corresponding 6"-mono-iodo product, namely 2",2"l-di-0-benzoyl-3,2',6',3",4"'-penta-N-tert butoxy-carbonyl-6"-mono-iodo-1-N-(L-4-amino-2-hydroxybutyryl)-dibekacin, (which gave a single spot at Rf 0.31 in the same silica gel thin layer chromatoyraphy just mentioned above).
This powder (220 mg, 0.15 m mol) was dissolved in 5 mQ
of dioxanel an~ the solution was subjected to a catalytic hydro-genolysis under a hydrogen pressure of 3.6 Kg/cm for 5 hours in a Paar apparatus in the presence of a Raney nickel catalyst (R~200, a produet of Nikko Rika Co., Japan) to eEfect the de-iodination.
The reaction solution was filtered to remove the catalyst. The filtrate was concentrated to dr~ness (169 mg) under recluced pressure ~ I758 and the re~idue was taken up in-to 10 m~ of 12~ ammonia methanol. The resulting solution was allowed to ~tand at ambient temperature overnight to effect the de-benzoylation~
The reaction ~olu-tion was concentrated to dryness (1~1 mg) under reduced pressure, and the residue was di~solved in 2 m~ of aqueous 90% trifluoroacetic acid, followed by being allowed to stand at ambient temperature for 45 minute~ to e~fect the removal of the ter~-bu-to~ycarbonyl groups.
The reaction solution wa~ concentrated to dryness under reduced pressure and the residue was washed with ethyl ether, a-~fording a faintly yellow powder (comprising the trifluoroacetate~ of l-N-(1~4-amino-2-hydroxybu-tyry1)-4"~6"-dideoxy- and 6"-deoxydibekacin~). This powder was di~solved in 2 m~ o~ water and adjusted to pH 7.8 by addition of lN
aqueous ammonia, and the resulting solution was passed through a column of 20 m~ of Amberlite CG-50 (NH4~) for ad~orption o~ the desired products. The ~mberlite col~unn wa~ washed with water (68 m~), with 0.2N aqueous ammonia (70 m~) and then with 0~5N aqueous ammonia (88 m~)) followed by elution with 0.6N aqueous ammonia (80 mQ) and then with 0~7N aqueou~ ammonia (50 m~ he eluate ~rom -the elution with the 0.6N aqueous ~mmonia were combined together and concentrated to dryne~s undar reduced pressure to give

7.2 mg (yield 8~o) Of a colorles~ powder o~ 1-N-(L-4 amino-2-hydroxybutyryl)-6"-deoxydibekacin (as the sesqui~oarbonate).
The fractions from the elutlon with the 0.7~ aqueous ammonia were combined together and concentrated to drynes~ under 1J17S~9 reduced pre~s~e to give 18.8 mg (yield 21~o) of a colorles~
powder of l~ 4-amino-2-hydro~ybu-tyryl)~4",6"-dideoxy-dibekacin (as the sesqui-carbonate). This product der composed a-t 142~147C and ga~e a ~pecific optical rotation ~D4 = + 84 (c 0.57 water)~
E~ample_4 Synthesis of 1-~ 4-amino-2--hydroxybutyryl)-6"-deoxydibekaein 6"-Deo~ydibekacin (as the sesqui-carbonate) (26.4 mg~
0.05 m mol) obtained in the Example 2 was dissolved in 0~5 mQ
of anhydrou~ dimethylsulfoxide~ and the resulting solution was admixed with 54.7 mg (0.24 m mol) of zine aeetate (Zn(C~3C02)2 2H20) and stlrred at ambient t~mperature for 20 hours to effect the formation o~ the comple~ of 6"
deoxydibekacin with æinc cation. The ~olution eontaining said compleg was admixed with 41~2 mg (0~165 m mol) of benzyloxycarbonyl-~-hydroxysuccinimide ester, and the admixture wa~ agitated for 20 hours at ambient temperature to effect the benzylo~ycarbonylation of the 3-, 2'- and 6'-amino groups of 6"-deo~ydibekaein which were not com-ple~ing with the zinc cation~ The reaction solution wa~
admixed with 30 mQ of water and a small volume of eon eentrated aqueou~ ammonia 90 that the reaction solution wa~ adju~ted to pH 11, whereby the breakdown of the zine-complexing with the 3~2'J6'-tri-N-benzyloxyearbonylated 6"-deoxydibekaein was effeeted, The reaction solution ~o treated whieh eontained the preeipitate as formed was ~7~819 filtered, and the precipitate collected (which comprised the 392',6'~tri-N-ben~yloxycarbonyl~6"-deo~ydibekacin) was dissolved in 5 m~ of dimethylsulfoxide~ To the re-sultant solution was added a ~olution of 0.02 m~ (0.14 m mol~
of ethyl trifluoroacetate in 1 m~ of dimethylsul-fo~ide, followed by agitation at ambient temperature for 3 hours to effect the selective 3"-N-trifluoroacetyla-tion and to give the reaction 301ution containing 3~2',6'-tri-N-benzyl-oxycarbo~yl 3"-N-trifluoroacetyl-6"-deo~ydibekacin. Thi~
reaction solution was admixed with 0~01 mQ (0.07 m mol) of triethylamine and with 26.3 mg (0.075 m mol) of N~h~droxy-succinimide ester o~ ~-4-benzyloxycarbonylamino-2-hydroxy-butyric acid, and the admi~ture obtalned wa~ stirred for 15 hours at ambient temperatuL~e to e~fect the acylation of the l-amino group of the ~"-deo~ydi~ekacin compound. The reaction mi~ture was admixed with 2 m~ of aqueous saturated sodium chloride and 2 m~ of ethyl acetate, and the ethyl acetate phase together with the precipitate formed wa3 concentrated to dryne~ to give 44.2 mg of a powder. This 20 powder wa~ admixed wîth 2 mQ of a mixture of tetrahydrofuran and lN aqueou~ ammonia (1:1 by ~olume), and the resultant admixture was stirred at ambient -temperature for 20 hour~
to effect the removal of the trifluoroacetyl g~oup. The reaction solution obtained was concentrated to a ~mall volume, followed by addition of 2 ~ of lN aqueous ammonia there-to~ The precipitate formed was removed by filtration and washed with water. This precipitate was dissolved in 1~758~9 _ 68 --20 mQ of a mixture of aoetic acid, methanol and water (2:1:1 by volume~ and the resulting solution9 after addition of 50 mg of 5% palladium-on-carbon thereto~ wa~
subjected to catalytic hydrogenolysis by passage of a hydrogen stream through said solution for 6 hours at ambient temperature. The reaction mixture was filtered to remove the catalyqt therefrom, and the filtrate was concentrated to dryness under reduced pressure. The residue was taken up into 0.3 m~ of water and the aqueous solution was adjusted to pH 7.8 by addition o~ lN aqueous ammonia. This solution wa~ charged into a column o~ 2 mQ
of Amberlite CG-50 (~E4+ ~orm) ~or adsorption o~ the desired product. The col~mn was then washed with 5 mQ
of water and with 5 m~ of O.lN aqueous ammonia, followed by elution with 5 m~ of 0.5N aqueous ammonia and then with 10 m~ o~ 0.8~ aqueous ammonia. The fractions from the elution with the 0~8N aqueous ammonia were combined together and concentrated to dryness under reduced pressure to give 10.0 mg of a colorle~s powder o~ the desired 1-N~ 4-amino~2-hyaroxybutyryl)-6"-deo~ydibekacin ~sesqui-carbonate).
Yield 32% Thi~ product decomposed at 132~139C ancL gave a 0pecific optioal rotation [~D3 ~ ~ 73 (c 0.3, water).
. ~ ~
Synthe~is o~ l-N-(L-4-amino-2-hydroxybutyryl)-4",6"-dideoxydibekacin The process of the above ~xample 4 was repeated using 25.6 mg (0~05 m mol) of 4",6'l-dideoxydibekac:in sesqui-1~75~19 _ ~9 _ carbonate instead of the 6"-deo~ydibekacin. A colorless powder o~ l-N~(L-4-amino-2 hydroxybutyryl)-4",6~'-dideoxy-dibekacin (sesqui-carbonate) was ob-tained. ~ield 9.0 mg ~290 .

Claims (3)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A process for the production of 1-N-(L-4-amino-2-hydroxybutyryl)-6"-deoxydibekacin or 1-N- (L-4-amino-2-hydroxybutyryl)-4",6"-dideoxydibekacin of the general formula (II) (II) wherein R represents a group selected from hydrogen and hydroxyl, which comprises:
(a) acylating the 1-amino group of 6"-deoxydibe-kacin, 4",6"-dideoxydibekacin or a partially amino-protected derivative thereof represented by the general formula (IX) (IX) wherein R is as defined above, when A represents hydrogen, at least one B represents a mono-valent amino-protecting group and the other B(s) each represent hydrogen, or at least one pair of A and B taken together form a di-valent amino-pro-tecting group and the other A(s) and B(s) each represent hydrogen, by reaction with an amino-protected derivative of L-4-amino-2-hydroxybutyric acid or a functional equivalent thereto, to produce a 1-N-acylated product of 6"-deoxydi-bekacin or 4",6"-dideoxydibekacin represented by the general formula (X) (X) wherein R is as defined above, A' represents hydrogen and B' represents a group selected from hydrogen and a mono-valent amino-protecting group, or A' and B' taken together form a di-valent amino-protecting group, or to produce an amino-protected 1-N-acylated product of 6"-deoxydibekacin or 4",6"-dideoxydibekacin represented by the general formula (X') (X') wherein R, A, B, A' and B' are as defined above; and (b) removing the remaining amino-protecting group(s) from the 1-N-acylated product of the general for-mula (X) or (X') to produce the desired compound of the general formula (II).

2. The process defined in claim 1, wherein step (a) 6"-deoxydibekacin or the derivative of general formula (IX), wherein R represents hydroxyl is used.
3. The process defined in claim 1, wherein step (a) 4",6"-dideoxydibekacin or the derivative of general formula (IX), wherein R represents hydrogen is used.
4. 1-N-(L-4-amino-2-hydroxybutyryl)-6"-deoxy-dibekacin or 1-N-(L-4-amino-2-hydroxybutyryl)-4",6"-di-deoxydibekacin of the general formula (II) (II) wherein R represents a group selected from hydrogen and hydroxyl, and pharmaceutically acceptable acid addition salts thereof; when prepared by the process defined in claim 1.
5. 1-N-(L-4-amino-2-hydroxybutyryl) 6"-deoxy-dibekacin, and pharmaceutically acceptable acid addition salts thereof; when prepared by the process defined in claim 2.
6. 1-N-(L-4-amino-2-hydroxybutyryl)-4",6"-dide-oxydibekacin, and pharmaceutically acceptable acid addition salts thereof; when prepared by the process defined in

claim 3.