United States Patent im
`Vorbruggen et al.
`
`[54] 5-AZAPYRIMIDINE NUCLEOSIDES
`Inventors: Helmut Vorbruggen; Ulrich
`[75]
`Niedballa, both of Berlin, Germany
`[73] Assignee: Schering Aktiengesellschaft, Berlin,
`Germany
`Mar. 12, 1971
`[22] Filed:
`[21] Appl. No.: 123,836
`
`[30]
`
`Foreign Application Priority Data
`Mar. 14, 1970 Germany
`
`2012888
`
`[52] U.S. CI
`[51] Int. CI
`[58] Field of Search
`
`260/211.5 R, 424/180
`C07d 51/52
`260/211.5, 211.5 R
`
`[56]
`
`References Cited
`UNITED STATES PATENTS
`6/1967 Shen et al
`3,328,388
`10/1967 Boxer et al
`3,346,561
`3,350,388 10/1967 Sorm et al
`3,531,464
`9/1970 Ryan et al
`
`260/211.5 R
`260/211.5 R
`260/211.5 R
`260/211.5 R
`
`Primary Examiner—Johnnie R. Brown
`Attorney, Agent, or Firm—Millen, Raptes & White
`
`ABSTRACT
`[57]
`5-Azapyrimidine nucleosides of the formula
`
`[in. 3,817,980
`[45] June 18, 1974
`
`H-N3 5P
`
`wherein X is NH or an oxygen atom and Z is a free or
`blocked sugar residue having cytotoxic, antiviral, en(cid:173)
`zyme-inhibiting,
`immunosuppressive,
`anti(cid:173)
`inflammatory and antipsoriatic activity are prepared
`by the reaction in the presence of a Lewis acid, of a
`l-O-acyl-, 1-O-alkyl- or 1-holoderivative ofa blocked
`sugar with a compound of the general formula
`
`•A,
`4J %/
`
`wherein D is a silylated or alkylated O-group and E
`is a silylated or alkylated O- or NH-group, the block(cid:173)
`ing groups of the sugar residue thereafter optionally
`being split off in a conventional manner to produce
`the conesponding free nucleoside.
`
`11 Claims, No Drawings
`
`Apotex v. Cellgene - IPR2023-00512
`Petitioner Apotex Exhibit 1016-0001
`
`

`

`3,817,980
`
`5
`
`10
`
`20
`
`1
`5-AZAPYRIMIDINE NUCLEOSIDES
`BACKGROUND OF THE INVENTION
`It is known that l-glycosyl-5-azacytosines possess
`cancerostatic and virostatic activity (Experientia 24,
`922 [1968] and Cancer Res. 28, 1995 [1968]).
`5-Azacytidine is produced, in accordance with Ger(cid:173)
`man Pat. No. 1,245,384, from the expensive and sensi(cid:173)
`tive 2,3,5-tri-0-acetyl-/3-D-ribofuranosylisocyanate via
`three stages. In a recently published work (J. Org.
`Chem. 35, 491 [1970]), the direct glycosidation ofthe
`silylated 5-azacytosine according
`to
`the Hilbert-
`Johnson reaction (J. Amer. Chem. Soc. 52, 4489
`[1930]) is described. However, according to this
`method, the 5-azacytidine is obtained in very poor
`yields, and 2'-deoxy-5-azacytidine is produced only in
`traces. The protected nucleosides could not be ob(cid:173)
`tained in pure form.
`In contrast thereto, it has now been found that 2,4-
`bis-O-alkyl and 2,4-bis-silyl derivatives of 5-azauracil
`and 5-azacytosine can be converted very readily and in
`good yields by the process ofthis invention by reaction
`with a blocked sugar derivative to form the protected,
`i.e., blocked, 5-azapyrimidine nucleosides which can
`then be converted into the corresponding free nucleo(cid:173)
`sides by saponification.
`SUMMARY OF THE INVENTION
`The hovel compounds of this invention are 5-
`azapyrimidine nucleosides of the general Formula I
`E
`
`tetra-0-acetyl-/3-D-fructopyranosyl,
`tetra-O-acetyl-D-fructofuranosyl,
`tetra-0-acetyl-/3-D-galactofuranosyI,
`tetra-0-acetyl-/3-D-galactopyranosyl,
`2,3,4,6-tetra-O-acetyl-glucopyranosyl,
`2,3,5,6-tetra-O-acety 1-glucofuranosy 1,
`2,3,4,6-tetra-0-acetyl-j8-D-mannopyranosyl,
`2,3,4-tri-O-benzoyl-rhamnopyranosyl,
`1,3,4,5-tetra-O-acetyl-sorbopyranosyl,
`2,3,4-tri-O-acetyl-xylopyranosyl,
`and (b) the compounds corresponding to each of the
`above wherein X is NH.
`The sugar reactants employed in the process of this
`invention are those having in the one-position a halo-
`15 gen atom, e.g., Cl, a carboxyester group or an O-ether
`group. Examples of monosaccharide reactants are
`those
`in which
`the sugar moiety
`is ribose, 2-
`deoxyribose, glucose, arabinose, allose, fructose, galac(cid:173)
`tose, galactosamine, mannose, rhamnose, sorbose, xy(cid:173)
`lose, glucosamine.
`Sugar moieties of particular importance are those of
`ribose, deoxyribose, arabinose, and glucose. Desirably,
`all the free hydroxy groups of the sugar moieties are
`-, masked. Suitable sugar masking groups are the block(cid:173)
`ing groups conventionally employed in sugar chemis(cid:173)
`try, including ester and ether groups, such as, for exam(cid:173)
`ple, acetyl and other alkanoyl groups, benzoyl and
`other
`aroyl groups, e.g., p-chlorobenzoyl, p-
`30 nitrobenzoyl and p-toluyl, and cleavable ether groups,
`e.g., a benzyl group.
`The method of preparing the halogenated blocked
`sugars is conventional, e.g., reacting the sugar with an
`alcohol in the presence of acid, protecting the free OH-
`35 groups with a suitable blocking group and forming the
`halogen-sugar by treatment with anhydrous hydrogen
`halide in an organic solvent, e.g., ether, acetic acid.
`The protected halogenosugars are prepared by the
`wherein X is NH or an oxygen atom and Z is a free or
`methods, described in W. W. Zorbach, R. S. Tipson:
`blocked sugar residue. They are prepared according to
`40 Synthetic Procedures in Nucleic Acid Chemistry, Vol.
`the process of this invention by the reaction in the pres(cid:173)
`1, Interscience Publishers, 1968, or see in: Advances in
`ence of a Lewis acid, of a l-O-acyl-, 1-O-alkyl- or 1-
`Carbohydrate Chemistry, Vol. 10 Academic Press, p.
`halo-derivative of a blocked sugar with a compound of
`247-249, 251-253, 1955.
`the general Formula II
`Examples of halogenated blocked sugars are:
`45 2,3,5,6-tetra-O-benzoyl-D-allosylchloride,
`2,3,5-tri-O-benz yl-D-arabinosylbromide,
`tetra-O-acety l-/3-D-fructopy ranosy Ichloride,
`tetra-O-acetyl-D-fructofuranosylchloride,
`tetra-0-acetyl-/3-D-galactofuranosylchloride,
`tetra-O-acetyl-a-D-galactopyranosylchloride,
`2,3,4,6-tetra-0-acetyl-glucopyranosylchl6ride,
`2,3,5,6-tetra-O-acetyl-glucofuranosylchloride,
`2,3,4,6-tetra-O-acetyl-a-D-mannopyranosyIchloride,
`
`H—N3 8N
`0=
`
`n
`wherein D is a silylated or alkylated O-group and E is
`a silylated or alkylated O- or NH-group, the blocking
`groups of the sugar residue thereafter optionally being
`split off in a conventional manner to produce the corre(cid:173)
`sponding free nucleoside.
`DETAILED DISCUSSION
`Compounds of this invention are those of Formula I
`wherein (a) X is an oxygen atom and Z is ribosyl,
`ribofuranosyl,
`glucosyl,
`arabinofuranosyl,
`glucopyranosyl, allosyl, arabinosyl, fructopyranosyl,
`galactofuranosyl, galactopyranosyl, mannopyranosyl,
`rhamnopyranosyl, sorbopyranosyl, xylopyranosyl and
`the corresponding 0-acylated compounds,
`e.g., wherein Z is:
`2,3,5,6-tetra-O-benzoy 1-D-allosyl,
`2,3,5-tri-O-benz yl-D-arabinosyl,
`
`50
`
`55
`
`60
`
`2,3,4-tri-O-benzoyl-rhamnopyranosylchloride,
`1,3,4,5-tetra-O-acetyl-sorbopyranosylchloride,
`2,3,4-tri-O-acetyl-xylopyranosylchloride.
`If a nucleoside having a sugar residue blocked by an
`O-acyl blocking group are desired as the final product,
`in addition to the abovementioned masking groups, the
`masking group can be the acyl group of, e.g., propionic
`acid, caproic acid, enanthic acid, undecylic acid, oleic
`acid, pivalic acid, cyclopentylpropionic acid, phenyl-
`,. acetic acid or adamantanecarboxylic acid.
`The starting triazines can be produced employing
`conditions described in: Silylation of Organic Com(cid:173)
`pounds, Pierce Chemical Company, Rockford, 111.,
`
`Apotex v. Cellgene - IPR2023-00512
`Petitioner Apotex Exhibit 1016-0002
`
`

`

`3,817,980
`
`—
`
`4
`3
`described type are very unstable in both the acidic and
`1968, pp. 18-26 and in Chem. Pharm. Bull. 12 (1964)
`basic pH range.
`352 and Z. Chem. 4 (1964) 303.
`The 5-azapyrimidine nucleosides of this invention
`Preferred specific silylation reactants include for ex-
`possess cytotoxic, antiviral, enzyme-inhibiting, immu-
`ample trimethylchlorosilane with bases as pyridine, tri-
`ethylamine or other tertiary amines, or with ammonia; 5 nosuppressive, anti-inflammatory, and antipsoriatic ac-
`hexamethyldisilazane with an acid catalyst as trimethyl-
`tivity. They can be administered in the same manner as
`chlorosilane, ammonium salts, sodium bisulfate; N-
`the known l-glycosyl-5-azacytosines. 5-Azapyrimidine
`silylated amines like trimethylsilylmethylamine, trime-
`nucleosides having a blocked sugar residue, i.e., com-
`thylsilylaniline, trimethylsilyldiethylamine, trimethyl-
`pounds of Formula I wherein Z is a blocked sugar resi-
`silylimidazole,
`silylated
`amides
`like N, O-bis- 10 due, are particularly suitable, due to their high resorba-
`trimethylsilylacetamide,
`N-trimethylsilyl-N,
`N'-
`bility for topical application, e.g., in the form of solu-
`diphenylurea and N-trimethylsilylphthalimide.
`t l o n s' salves< a™* gels-._,
`, , . .
`u
`j u
`Examples of silylated starting compounds for the pro-
`The compounds produced by the process of this m-
`cess of this invention are those of Formula lla:
`vention possess cytotoxic, antiviral, enzyme-.nh.b.ting,
`15 immunosuppressive, anti-inflammatory,
`and anti-
`psoriatic properties.
`X—siOower aityDi
`Because the compounds of this invention can be em-
`I
`ployed in vitro as well as in vivo, they are especially
`if ^j
`useful as disinfectants, e.g., in the sterilization of medi-
`I
`ll
`na 20 cal instruments and the like, as well as in cleansing so-
`Oower aikyDiSi-o-l^J
`lutions for cleaning woodwork, towels, linen, blankets,
`-•
`---••--•—
`dishes and the like, to prevent spread of infection,
`-^n,, „»<,fi»„»H
`. .„ „ , ..
`. ,. _.
`.
`^
`this invention can be em-
`wherem Xis-O-or-NH- Of these especially preferred
`UJS of
`.n m i x t u r^ w i th conventional pharmaceutical
`are those where.n the lower-alkyl group which can
`i e n t s. .C a r r i er substances can be such organic or
`contain one to four carbon atoms, is methyL These 25 ^J
`compounds are prepared by reacting 2,6-dioxy-5-
`i n o r^a n ic s u b s t a n c es s u i t a bie for parenteral, enteral, or
`azapynmidme or 2-oxy-6-amino-5-azapyr.midine with
`^
`l i c a t i on a nd w h i c ht of c o u r s e) do n ot d e le-
`a hexa-alkyl, preferably hexa-lower-alkyl dis.laz.ane,
`J . ^, ^
`w.th ^
`n o v el c o m p o u n d S) s u ch aSi f or
`e.g., hexamethyl-disilane, or w.th a trialkyl, preferably
`lef w a t e ri vegetable oils, polyethylene glycols,
`e
`tri-lower-alkyl, silyl halogenide, e.g., trimethylsilyl 30 ge,a t in l a c t o s e) aniyiose, magnesium stearate, talc, vas-
`chloride. Of
`the starting compounds,
`the bis-
`|l i n c> choIesteroI, etc. '
`trimethylsilyl ethers are preferred.
`F or pa r e n t e r al application, particularly suitable are
`The best yields are obtained in the process of this in-
`s oiu t i o n S( preferably oily or aqueous solutions, as well
`vention when E and D are both alkylated groups or
`as S U Spe n s i o n S; emulsions or implants. Ampoules are
`both silylated groups, i.e., when E is an alkylated O- 35 convenient unit dosages.
`group, D is preferably an alkylated O-group, and when
`F or e n t e r aI application, particularly suitable are tab-
`E is a silylated NH-group, D is preferably a silylated O-
`l e ts or d r age es which are also characterized by talc
`group.
`and/or a carbohydrate carrier or binder or the like, the
`The Lewis acid employed in the reaction is prefera-
`carbohydrate carrier being preferably lactose and/or
`bly soluble in the reaction solvent. Examples of pre- 40 c o rn s t a r ch and/or potato starch. A syrup or the like
`ferred Lewis acids are tin tetrachloride, titanium tetra-
`ajso be u s ed wherein a sweetened vehicle is em-
`c an
`chloride, zinc chloride, and boron trifluoride etherate.
`ployed.
`Examples of other Lewis acids are silver perchlorate
`por topical application, viscous to semi-solid forms
`and mercury halides.
`are used such as liniments, salves or creams, which are,
`The reaction can be conducted in the customary 45 if cjesire(}) sterilized, or mixed with auxiliary agents,
`inert organic solvents, e.g., in methylene chloride, chlo-
`SUch as preservatives, stabilizers, or wetting agents, or
`roform, ethylene chloride, acetone, dioxane, tetrahy-
`Salts for influencing the osmotic pressure, or with
`drofuran, dimethylformamide, benzene, toluene, car-
`buffer substances.
`bon disulfide, carbon tetrachloride, tetrachloroethane,
`j he substance of this invention is generally adminis-
`chlrorbenzene and ethyl acetate.
`50 tered to animals, including, but not limited to, mam-
`The reaction can be conducted at room temperature
`mals and avians, e.g., cattle, cats, dogs, and poultry,
`of at higher or lower temperatures, preferably 10o-60o
`A daily dosage comprises about 1 to 40 g. active
`C. The reactants are generally employed in the reaction
`compound of this invention on oral administration and
`in approximately equimolar amounts. However, the py-
`. a 5 percent greasy ointment on topical administration,
`rimidine compound can be utilized in a small excess in
`in general, the mg/kg ratio is preferably about 50 to
`order to obtain as close to quantitative conversion of
`500 mg. per kg. of body weight. The dose can be ad-
`the sugar component as possible.
`ministered once per day or in increments throughout
`For producing the free nucleosides of this invention,
`the day.
`i.e., compounds of Formula I wherein Z is a free sugar
`Without further elaboration, it is believed that one
`residue, the blocking groups can split off in a conven-
`skilled in the art can, using the preceding description,
`tional manner, e.g., with an alcoholic solution of am-
`utilize the present invention to its fullest extent. The
`monia or an alcoholate. In the reaction with ammonia,
`following preferred specific embodiments are, there-
`an O-alkyl group present in the four-position on the tri-
`fore, to be construed as merely illustrative, and not lim-
`azine ring is converted to an NH-group.
`65 itative of the remainder of the disclosure in any way
`The course taken by the novel process of this inven-
`whatsoever,
`tion was not predicted and is highly surprising because
`Preparation of the bissilyl compound of 5-azacytosine:
`it is known that triazine compounds of the above-
`
`Apotex v. Cellgene - IPR2023-00512
`Petitioner Apotex Exhibit 1016-0003
`
`

`

`3,817,980
`
`6
`EXAMPLES
`i-,-)
`, „ , .^
`,
`, „ „ -. c
`l-(2'-Deoxy-3' S'-d.-O-p-toluy^-D-ribofuranosyl)-2-
`oxo-4-am.no-1,2,-d.hydro-1 .^3,5- "a^e
`
`5
`11.2 g. of 5-azacytosine, 100 ml. of hexamethyl-
`disilazane and 1.5 ml. of trimethylchlorosilane were
`boiled for 15 hour under reflux conditions. Then, all
`low-boiling components (up to 125° C./760 torr) were
`distilled of!,andLresiduewasdistill?
`3j 5^ ^ . p.
`of 2 K,e
`^ 39
`^ ^^
`^
`2-
`thus ob aimng, in quant.tatwe yield (25 6 g
`t o l u y,.r i b o f u r anosyl chloride (10 mmol) in 100 ml. of
`trimethylsilyloxy-4-trimethylsilylamino-l,3,5-tnazine.
`absolute dichloroethane. After the addition of 0.84 ml.
`Preparation of 2.4-dimethoxy-l ,3,5-tr.azine:
`15 g. of 2,4-dimethoxy-6-chlor-l,3,5-triazine (The 10 o f S n C l4 (7.2 mmol) in 10 ml. of absolute dichloroeth-
`Chemistry of Heterocyclic Compounds, S-Tnazines,
`a n e) t he r e action mixture was agitated for 2 hours at
`page 71/72) were hydrogenated in the presence of 4.6
`T00'm temperature, then diluted with 200 ml. of methy-
`g. of Pd (5 percent)/C in a solution of 500 ml of abs.
`l e ne chloride, and worked up as described in Example
`ether and 12 ml. of abs. triethylamine until the take up
`j By filtration of the residue in a solution of toluene/e-
`of one equivalent of hydrogen. After filtration from the j 5 thanol over kieselguhr, the 5-azacytosine was removed,
`solid, the solution was evaporated. The residue was re-
`An a,/3-mixture was crystallized from toluene; this mix-
`crystallized from about 150 ml. of M-hexane. The yield
`ture was recrystallized from ethanol.
`of crystalline 2,4-dimethoxy-1,3,5-triazine was 5.3 g.,
`Yield: a,j3-mixture: 3.55 g. (76.6 percent of theory).
`m. p. 480-520 C.
`'
`,_ *
`20 The /3-anomer was obtained in the pure form by frac-
`tjo n al cryStallization from ethyl acetate.
`Yield: 1.93 g. (41.6 percent of theory), m.p. 196° C.
`
`EXAMPLE 1
`
`EXAMPLE 4
`
`..
`
`a.
`
`3',
`j.(2',
`5' -Tri-O-benzoy l-/3-D-ribofuranosyl )-2-oxo-4-amino-
`1,2-dihydro-1,3,5-triazine
`12.5 millimols of the bissilyl compound of 5- "
`, 3 ';4 ' , 6 ' - T e t r a - 0^ f f . ^ W ™0^
`l-(2'
`azacytosineinl8.8ml.ofabsolutedichloroethanewas
`2-oxo-4-methoxy-l,2-dihydro-l,3,5-triazine
`A A A .
`1 .-
`e « n „ „<• 1 n o,.Qt„i 0 -x <; tri n
`2,4-dimethoxy-1,3,5-triazine (11 mmol)
`added to a solution of 5.0 g. of l-O-acetyl-2 3,5-tr.-0-
`a;o l u t i on of 3^ g.Wpentaacety. glucose
`J ^ J^
`benzoyl-ribofuranose (9.92 mmol) ,n 100 ml. of abso-
`lute dichloroethane. Then, the reaction m.xture was 30 ( 1 0 m i n o l ) in JQO ml. of absolute dichloroethane. After
`mixed with 1.68 ml. of SnCl4 (14.4 mmol) m 20 ml. of
`^ ^ .^
`of L 6g ml of S n C l 4 ( 14 .4 m m oi) in 20 ml.
`absolute dichloroethane, and the mixture was stirred
`of a b s o l u te dichloroethane, the reaction mixture was
`for 2 hours at room temperature. After dilution with
`s t i r r ed f or 3 h o u rs at r o om temperature. After dilution
`200 ml. of methylene chloride, the reaction mixture
`w i th 200 ml. of methylene chloride, the mixture was
`was washed with an NaHCOa solution. The organic 35 worked up as set forth in Example 1.
`phase was filtered through kieselguhr, the latter having
`jhe n u cie o sjde was crystallized from ethanol in the
`been washed with a small amount of methylene chlor-
`form 0f colorless needles. Yield: 1.73 g. (37.8 percent
`0f theory), m.p. 2360-2370 C.
`ide. The combined organic solutions were dried over
`Na2S04 and evaporated under vacuum. The residue
`b. l-[|3-D-Glucopyranosyl]-5-azacytosine
`was dissolved in toluene and filtered over kieselguhr in 40
`j 5
`l-[2',3',4',6'-Tetra-0-acetyl-/3-D-
`g
`0f
`order to remove 5-azacytosine. Final remainders were
`glucopyranosyl]-2-oxo-4-methoxy-l,2-dihydro-l,3,5-
`eliminated by filtering the ethanolic solution over kie-
`triazine (3.28 mmol) was dissolved in 50 ml. of abso-
`ggjoyh,.
`lute methanol saturated with ammonia, and the reac-
`Crvstallization from ethanol yielded the nucleoside in
`tion mixture was stirred for 3 hours at room tempera-
`the form of colorless needles.
`45 ture. The solvent was then evaporated under vacuum
`Yield- 3 85 g
`(69.8 percent of theory), m.p.
`and the residue was divided between ethyl acetate and
`6
`' r . 1 8 70r
`F
`water. The aqueous phase was concentrated under vac-
`1 S0
`uum and the residue recrystallized from moist metha-
`nol.
`EXAMPLE 2
`50 Yield: 487 me. (54.2 percent of theory), m.p. 259°—
`m
`'~
`, o ^
`•
`,„.
`,
`.
`^ f £• ^
`^P
`l-(2',3',4',6'-Tetra O acety -^-D-glucopyranosyl)2-
`l.rft-D-Glucopyranosyl]-5-Azauracil
`oxo-4-amino-l,2-dihydro-l,3,5-triazine
`^^'^'^'^'-Tetra-O-acetyl-ZS-D-
`of
`12.5 millimols of the bissilyl compound of 5-
`^ ^
`lucopyranosyl]-2-oxo-4-methoxy-l ,2-dihydro-l ,3,5-
`azacytosine in 18.8 ml. of absolute dichloroethane was
`added toasolutionof 3.9g. of pentaacetylglucose (10 55 tr i a z i ne (2.45 mmol) in 50 ml. of absolute methanol
`mmol) in 100 ml. of absolute dichloroethane. After the
`w as m i x ed w i th a solution of 146 mg. of sodium (6.35
`addition of 1.68 ml. of SnCl., (14.4 mmol) in 20 ml. of
`m mol) in 50 ml. of absolute methanol. The mixture was
`absolute dichloroethane, the reaction mixture was agi-
`stirred for 0.5 hour at room temperature, then mixed
`with 20 g. of an ion exchanger in the H+-form, and agi-
`tated for 3 hours at room temperature.
`Then, the mixture was diluted with 200 ml. of methy- 60
`fOT another 2 hours at room temperature. The ex-
`tated
`
`lene chloride and worked up as described in Example
`changer was filtered off and the mixture washed thor-
`1. The 5-azacytosine was removed by filtering the etha-
`oughly with moist methanol. The combined solutions
`nolic solution of the residue over kieselguhr. Crystalli-
`were evaporated to dryness under vacuum. The nucleo-
`zation from acetone/toluene resulted in the nucleoside, 65 side was crystallized from moist methanol in the form
`in the form of colorless needles.
`of colorless needles
`Yield- 2 42 g
`(54.7 percent of theory), m.p.
`Yield: 363 mg. (53.8 percent of theory), m.p. 1 8 2-
`210o-212Q C
`1 8 50 C- (t he s u b s t a n ce is Pr e s e nt as a sol v a t e)-
`
`Apotex v. Cellgene - IPR2023-00512
`Petitioner Apotex Exhibit 1016-0004
`
`

`

`3,817,980
`
`EXAMPLE 5
`l-(2',3',4'-Tri-0-acetyl-j8-D-ribopyranosyl)-2-oxo-4-
`amino-1,2-dihydro-l ,3,5-triazine
`12.2 millimols of the bissilyl compound of 5-
`azacytosine in 18.8 ml. of absolute dichloroethane was
`added to a solution of 3.18 g. of tetraacetyl ribopyra-
`nose (10 mmol) in 100 ml. of absolute dichloroethane.
`After the addition of 1.68 ml. of SnO,, (14.4 mmol) in
`20 ml. of absolute dichloroethane, the mixture was 10
`stirred for 2 hours at room temperature. After dilution
`with 200 ml. of methylene chloride, the reaction mix(cid:173)
`ture was worked up as described in Example 1. The nu(cid:173)
`cleoside was purified by chromatography on silica gel.
`The product was crystallized from ethanol in colorless 15
`needles.
`Yield: 1.92 g. (51.9 percent of theory), m.p.
`128°-136° C. (the substance is present as a solvate).
`EXAMPLE 6
`
`20
`
`25
`
`30
`
`5-Azacytidine
`1.5 g. of 5-azacytidine tribenzoate (2.7 mmol) was
`dissolved in 100 ml. of absolute methanol saturated
`with ammonia, and then agitated for 8 hours at room
`temperature. The solvent was thereafter removed by
`evaporation under vacuum, and the residue was distrib(cid:173)
`uted between ethyl acetate and water. The aqueous
`phase was concentrated under vacuum. The residue
`was crystallized from moist methanol.
`Yield: 509 mg. (77.5 percent of theory), m.p.
`2320-233o C. (decomposition).
`EXAMPLE 7
`1 -(j8-D-Glucopyranosyl )-5-azacytosine
`l-(tetraacetyl-glucopyranosyl)-5- 35
`1.6
`g.
`of
`azacytosine (3.62 mmol) was dissolved in 100 ml. of
`absolute methanol saturated with ammonia and agi(cid:173)
`tated for 3 hours at room temperature. The reaction
`mixture was worked up as described in Example 6.
`Crystallization from moist methanol yielded colorless 40
`needles.
`Yield: 734 mg. (73.9 percent of theory), m.p.
`2570-2590 C. (decomposition).
`EXAMPLE 8
`2'-Deoxy-5-azacytidine
`1.40
`g.
`of
`l-(2'-deoxy-3,5-di-0-p-toluyl-/3-D-
`ribofuranosyl)-5-azacytosine
`(3.02 mmol)- was dis(cid:173)
`solved in 50 ml. of absolute methanol saturated with
`ammonia and stirred for 3 hours at room temperature.
`The reaction mixture was worked up as set forth in Ex(cid:173)
`ample 6. The nucleoside was crystallized from ethanol.
`
`45
`
`50
`
`Yield: 495 mg. (70.4 percent of theory), m.p.
`198°-1990 C. (decomposition).
`EXAMPLE 9
`l-(/3-D-Ribopyranosyl)-5-azacytosine
`0.6 g. of l-(2',3',4'-tri-0-acetyl-/3-D-ribopyranosyl)-
`5-azacytosine (1.62 mmol) was dissolved in 100 ml. of
`absolute methanol saturated with ammonia and stirred
`for 3 hours at room temperature. The reaction mixture
`was worked up as described in Example 6. The nucleo(cid:173)
`side was crystallized from moist methanol.
`Yield: 298 mg. (75.2 percent of theory), m.p. 160oC.
`(decomposition; the substance is present as the sol(cid:173)
`vate).
`
`55
`
`60
`
`65
`
`8
`The preceding examples can be repeated with similar
`success by substituting the generically and specifically
`described reactants and/or operating conditions of this
`invention for those used in the preceding examples.
`From the foregoing description, one skilled in the art
`can easily ascertain the essential characteristics of this
`invention, and without departing from the spirit and
`scope thereof, can make various changes and modifica(cid:173)
`tions of the invention to adapt it to various usages and
`conditions.
`What is claimed is:
`1. A 5-azapyrimidine nucleoside ofthe formula
`X
`
`A
`
`H -N
`
`wherein X is NH or an oxygen atom and Z is a mono(cid:173)
`saccharide residue wherein at least one of the hydroxy
`groups is masked with a member selected from the
`group consisting of acetyl, benzoyl, p-chlorobenzoyl,
`p-nitrobenzoyl, p-toluyl and benzyl.
`2. A compound of claim 1 wherein X is NH.
`3. A compound of claim 1 wherein X is an oxygen
`atom.
`4. A compound of claim 1 wherein the monosaccha(cid:173)
`ride residue is selected from the group consisting of ri(cid:173)
`bose, deoxyribose, arabinose and glucose.
`5. A compound of claim 1 wherein all of the free hy(cid:173)
`droxy groups of the monosaccharide residue are
`masked.
`6. A compound of claim 1, l(2',3',5'-tri-0-benzoyl-
`/3-D-ribofuranosyl )-2-oxo-4-amino-1,2-dihydro-1,3,5-
`triazine.
`7. A compound of claim 3, l-(2',3',4',6'-tetra-0-
`acetyl-/3-D-glucopyranosyl)-2-oxo-4-amino-1,2-dihy-
`dro-l,3,5-triazine.
`8. A compound of claim 3, l-(2'-deoxy-3',5'-di-0-p-
`toluyl-j3-D-ribofuranosyI )-2-oxo-4-amino-1,2-dihydro-
`1,3,5-triazine.
`9. A compound of claim 3, l-(2',3',4'-tri-0-acetyl-/3-
`D-ribopyranosyl )-2-oxo-4-amino-1,2-dihydro-1,3,5-
`triazine.
`10. A process for the preparation of 5-azapyrimidine
`nucleosides of the formula
`
`-A.
`
`-m BN
`0=1 2 ,6
`• N/
`
`wherein X is NH or an oxygen atom and Z is a blocked
`sugar residue which comprises reacting in the presence
`of a Lewis acid the 1-O-acyl-1-O-alkyl- or 1-halo-
`derivative of a blocked sugar with a compound of the
`formula
`
`A
`
`wherein D is a silylated or alkylated O-group and E is
`a silylated or alkylated O- or NH-group to form said 5-
`azapyrimidine nucleoside.
`11. A process according to claim 10 wherein the
`Lewis acid is tin tetrachloride, titanium tetrachloride,
`zinc chloride or boron trifluoride etherate.
`
`Apotex v. Cellgene - IPR2023-00512
`Petitioner Apotex Exhibit 1016-0005
`
`

`

`UNITED STATES PATENT OFFICE
`CERTIFICATE OF CORRECTION
`PATENT NO. : 3 , 8 1 7 , 9 80
`DATED
`: J u ne 1 8, 1974
`INVENTOR(S) : H. Vorbruggen et al
`
`It is certified that error appears in the above-identified patent and that said Letters Patent
`are hereby corrected as shown below:
`
`Column 8, l i ne 52, change "sugar" to —monosaccharide—,
`
`l i ne 54, change "sugar"
`to —monosaccharide—. -
`Signed and Sealed this
`
`ninth D ay of September 1975
`
`[SEAL]
`
`Attest:
`
`RUTH C. MASON
`Attesting Officer
`
`C.MARSHALL DANN
`Commissioner of Patents and Trademarks
`
`Apotex v. Cellgene - IPR2023-00512
`Petitioner Apotex Exhibit 1016-0006
`
`