DD83142B1 - Process for the preparation of cytostatically active 2 *, 3 *, 5'-trideoxy-3 ', 5'-dihalogen-nucleosides - Google Patents

Description

14 8 813

The invention relates to a process for the preparation of oytostatically active 2 ', 3', 5 ^I- trideoxy-3 ^I »5'-dihalogennucleosiden of the general formula I.

 ι "

, f ^!

in which X and X ^{} are} halogen and P is a pyrimidine base having an on-structure at C-2, such as thymine.

It is known that some sugar-halogenated, especially fluorinated, pyrimidine-nucleosides exhibit biological activity and, in particular, are cytostatically active. Thus, for example, the recently prepared 5- ^r- deoxy-5'-fluoro-thymidine (DWP 65,936) inhibits in vitro the proliferation of Ehrlich ascites tumor cells. The isomeric 3 ¹ -deoxy-3'-fluoro-thymidine 'unfolds a cyto-

Static activity against tumor cells also in vivo , probably based on different mechanisms of action. Other 5'-deoxy-5'-halo- and 3'-deoxy-3-halopyrimidine nucleosides have also been shown to inhibit inhibition.

- ^ AA ft 81

, It was to be expected that 3 ¹ , 5 ^f -dihalogfiierte nucleosides

"of this type, in particular the corresponding fluorine-containing

ν -

Compounds which are also biologically active and possibly improved over the monohalogen nucleosides.

4 ' ...'.

have serte properties.

The invention has for its object to develop a process for the preparation of 2 ', 3', 5'-trideoxy-3 ', S'-aihalogen-nucleosides.

s '. '.' · '

According to the invention 2 ¹ , 3 ¹ , 5'-trideoxy-O ¹ »5'-dihalogen-. nucleosides prepared by the hydroxyl groups at C-3 - and C-5 ^f of 2 ^! -Desoxy-nucleosides of the general formula II

^ CHi ^ ρ

OH

in which P has the abovementioned meaning, after activation, preferably by mesylation or tosylation, directly (C-5 ¹ ) bzv /. exchanged after halous intramolecular 2,3'-Anhydronucleosid formation (C-3 ¹ ) after halogen.

The formation of the reactive 2,3'-anhydro bridge required prior to the introduction of halogen to C-3 * may optionally also be achieved by reacting the starting compound of general formula II directly or after esterification, ζ · Β. Sulfonylation, the 5'-0H group or after their Halogensubstitcfcion in known per se with diethyl (2-chloro-1,1,2-trifluoroethyl) -amine.

* 2

VAS 81 * 3

For the preparation of 2 ·, 3 ', 5'-trideoxy-5'-nucleosides is useful initially in per se known

Selectively mesylate the 5 '~ 0H group of II or ^v

tosylated and the 5 '-Sulfonyloxygruppe with a suitable Pluorid, preferably potassium fluoride or tetrabutyl ammonium fluoride, exchanged for fluorine. After that.' is either by reaction with diethyl (2-chloro-1, 1,2-tri-

fluoroethyl-amine or by mesylation of the 3'-0H-G-group (

and subsequent alkali treatment, the 2,3'-anhydro-5'-deoxy-5'-fluoro-nucleoside prepared, which is then converted by reaction, preferably with hydrogen halides in the desired 3'-halogen compounds.

For the preparation of 2 ', 3 ^f, 5 ^f -Tridesoxy-3'-fluoro-5'-halogennucleosiden is zv; eckmäßigerv / else also in the first mesylated 5'-0H group of II per se known manner or tosylated, the Sulphonyloxy group preferably with

Tetrabutylammonium- or, an "alkali halide by the f

corresponding halogen substituted and the 5'-deoxy-5'-halogen compound as described above via the 2,3 ^f -Anhydronucleosid reacted with hydrogen fluoride to 3'-PIuOr-5 ¹ -halogen compound.

The indicated order of the reaction steps is *

largely variable. Thus, it is possible, for example, first to mesylate both OH-G groups of II in a one-step process, then to dissolve the desired halogen in a manner known per se by way of the 2. 3 ^l -anhydro-5'-O available via alkali treatment. mesyl-nuoleosilic in the

^ '- introduce position and finally exchange the 5'-O-mesyloxy group for halogen. Conversely, it is also possible primarily to halogen-substitute the 5 ^r- position of the dirnesyl derivative of II and then the halogen to the second step

Introduce the above mentioned reaction formula on the C-3 ^1. / The introduction of halogen, such as fluorine and chlorine, ah C-3 ^! is carried out by heating the 2.3 ^t -Anhydro derivatives with the corresponding hydrohalic acid in an organic solvent, preferably an ether such as dioxane, optionally with the addition of metal halides, preferably of corresponding aluminum halides, to 60 to 180 C, preferably to 100 to 150 C. . The hydrogen halide concentration is 0.01 to 10 <%>, preferably 0.05 to 1 fo "The reaction is carried out either with an excess of hydrogen halide, '.vorzugsweise' in the case of hydrogen fluoride, or with a äquimolareh amount, preferably in Ml of , Hydrogen chloride. Excess hydrogen halide is neutralized with a suitable compound, for example CaCO 2, the halide formed is separated off, the solvent is removed in vacuo and the 3'-deoxy-3'-halogen compound is purified by recrystallization or column chromatography. In the case of 3'-chloro-derivatives ^f 5 -dideoxy-3 *, S'-dihalo-nucleosides because of the uniform and practically quantitative Heaktionsverlaufs no intermediate purification is at a further processing into 3 * required "

I H ff Hf f 3

The substitution of the 5'-SuIfonyloxygruppe by halogen is effected by reaction Rait halides, preferably ^"r ammonium and alkali halides such as tetrabutylammonium fluoride, potassium fluoride or lithium chloride, in organic solvents such as dimethylformamide, acetone or alcohols at room temperature or by heating the components.

After abortion of the solvent, the reaction pro -.

products isolated by column chromatography.

The compounds prepared according to the invention show a

C selective inhibition of DNA synthesis and a strong # yto

static effectiveness. For example, a 50% inhibition of DNA synthesis of Ehrlich ascitic tumor cells in vitro is achieved by 3 '> 5'-dideoxy-3', 5'-difluorothymidine at a concentration of 0.09 mM. The proliferation of Ehrlich ascitic tumor cells in vitro is mediated by;

same compound in a concentration of 0.3 mM ^

inhibited to 50 % . The effectiveness is at least 10 times stronger than that of the known dichloro- and dibromo derivatives.

'. ·'. f

Example 1 . · -

1 g of 5'-deoxy-5'-fluoro-tliymidin is kept in 10 cm of anhydrous pyridine with 0.5 cm ^J mesyl chloride overnight at ⁰ ° C closed. After addition of about 2 g of ice is allowed to stand for 30 minutes and. Then concentrated in vacuo to dryness. After repeated addition and stripping of ethanol, the residue begins to crystallize. The obtained

^ 148 813

5 ^f -Desoxy-5 ^f -fluoro-3'-O-mesyl-thymidine is taken up in acetone / ethanol (ca.9: 1) and washed out. Yield approx. 1 g. From the mother liquor can gain another 150 mg. Melting point after recrystallization from ethyl acetate 168C.

750 mg 5 ^r -deoxy-5-fluoro-3 ^{f f} -0-mesyl-thymidine be in

3 '' '

Suspended 40 cm of water, which was previously brought to a pH of 9 to 10 with triethylamine / ethanol (1: 1) »The mixture is heated to near boiling and the rapid drop in pH by adding additional triethylamine constantly compensated. - If the pH remains constant, filter and concentrate in vacuo to dryness. After two additions and aborting of ethanol (in vacuo), the residue crystallized on trituration with ethanol. Yield 320 mg 2.3 ^l -Anhj'-dro-5 ^l desoxy-5'-fluoro-thymidine :. The melting point of the thin layer chromatography (silica gel HP, Merck, chloroform / .Methanol = 8: 2) uniform product after recrystallization from ethanol at 224 to 226 C.

100 mg of ^^ '- anhydro-S'-deoxy-S'-fluoro-thymidine

      - '3 ·' ·

with 100 mg'AlFo in 70 cm .0.1%. HP in dioxane in one

3 '' ''

100 cm steel vessel with Teflon seal in preheated bath heated to 150 C for 3 hours. After cooling it will

ο. , , .- ·

diluted to about 20 cm with water, neutralized with powdered calcium carbonate, filtered and the residue several times

Washed thoroughly with warm acetone. The combined filtrates of three batches of this size are concentrated under reduced pressure and the syrupy residue is separated by column chromatography on 50 g of silica gel H (Merck) (column diameter 2.2 cm) with t- chloroform as eluent. The 3 ', 5'-dideoxy ~ 3', 5'-difluorothymidine contained in the fractions 27 "to 35 (each 10 cm) crystallizes on stripping off the ^λ 1 -chloroform and is washed with ethyl acetate / cyclohexane (7: 3). taken up and washed yield of 3 beginnings 133 mg · melting point 135 C after recrystallization from water.

UV absorption in 0.1 η HCl: TL max 266 nm, Ümin 235 nm; in 0.1 η NaOH: $ max 267.5 nm ,. Jtmin 247 nm · R ^ value in thin layer chromatography on silica gel HP (Merck), 0.25 mm, with ethyl acetate / ethanol / water (4: 1: 2, upper phase): 0.68.

Example 2

'· -:'. "3

244 mg of 5'-DeSOXy-S'-fluoro-thymidine are treated with 0.32 cm diethyl (2-chloro-1,1,2-trifluoroethyl) -amine in 2.5 cm ^{3 of} acetone for 30 minutes at 70 C (bath temperature ) is heated. It is then concentrated in vacuo and the residue säulenohromtographisch on 30 g of silica gel H (Merck) with n-propanol / water (8: 2) isolated "The fractions (each 3 cm ^J) 15 to 34 include unreacted Ausgarigsprodukto Fractions 35 to 48 after concentration 51 rag 2j3'-anhydro-5 ^l desoxy-5 ^t -fluor- »thymidine. SchraelEpunkt of colorless

Prisms after two recrystallizations from absolute ethanol 225 to 228 ° C · UV absorption in H ₂ O: .Jtmax 251.5 (69080), min. 220 nm (£ 6600). ,.

The further reaction of the 2,3 ^l -anhydro-5 ^l -deoxy-5- ^t- fluorothymidine with fluorine / hydrogen peroxide in dioxane and the isolation of the formed 3 ', 5- ^T- dideoxy-3 ^f , 5'-difluoro-thymidine is carried out as in example 1.,

Example 3

3 g of 2,3'-anhydro-5 ^l -0-mesyl-thymidine, prepared in a known manner from 3 ', 5 ^f -di-Q-mesyl-thymidine, with 3 g of AlF- in 1.5 1 0, 1 <%> Fluorv / on Hydrogen in dioxane in a sealed steel vessel in a preheated oil bath for 2 hours at 150 ⁰ C heated (bath temperature). After cooling down

3 .- '. is diluted with about 400 cm of water, with powdered CaCO, neutralized, filtered and the residue washed again thoroughly with warm acetone. The filtrate is concentrated under reduced pressure and the residue is purified by column chromatography on a column (diameter 4 cm) of 300 g of silica gel H (Merck) with chloroform / acetone (3: 1) as eluant. The fractions (10 cm each) 100 to 184 contain 3 ^{t of} fluoro-5 ' ^l -0-mesylthymidine, which crystallizes out on concentration in vacuo. It is taken up with chloroform and washed out. Yield 1.94. g · melting point 1 59 C. After recrystallization from isoprcpanol melting point 162.5 CV

-3-

500 mg of 3'-fluoro-5'-O-mesyl-thymidine are dissolved in 8.5 cm of anhydrous dimethylformamide with 2.6 g of tetrabutylammonium. fluoride heated to 50 C for 20 hours. After concentration in vacuo is taken up with a little water and desalted on an ion exchange column of Dowex 50 WK 8 The aqueous eluate is allowed to drip into a suspension of 2 g of CaCO 2 in water. The filtrate is concentrated in vacuo, the residue taken up with a little chloroform and purified by column chromatography on 50 g of silica gel H (Merck) with chloroform. The further work-up of 3 ', 5 ^T- dideoxy-3V, 5'-difluoro-thymidine is carried out as in Example 1. Yield: 50 mg. - ~

Example 4

340 mg of 2,3 ^f -anilydro-5'-deoxy-5 ^L -fluorothymidine, prepared according to Example 1 or 2, are refluxed with moisture and 136 g of anhydrous dioxane containing 1.5 m mol of hydrogen chloride for 1 hour After heating in vacuo, several times ethanol is added and the mixture is concentrated again. _o Trituration with ethyl acetate / cyclohexane (7: 3) causes the residue to crystallize. "The 3 ', 5 ^t ~ dideoxy-3 ^f -chloro-5'-fluoro-thymidine is taken up with the same solvent mixture and washed out. Yield:

362 mg. Sclimelzpuhkt 154 to 156 ° C.

UV absorption in 0.1. η HCl: tmax 266.5 nm (£ 10 660), % min 234.5 nm. £ ₂₆₀ 9730; in 0 ₅ 1 η NaOH: λ raax 267.5 nm

• (^ 8840), -imine 246 nm ·

; - * -. 1 48 813

Example 5

520 mg of 5'-chloro-S'-deoxy-thymidine, prepared in. Known from 5 '' 0-tosyl-thyinidine with LiCl, in 5 cnr anhydrous pyridine with 0.46 cm ^ mesyl chloride overnight at ⁰ C kept closed. Thereafter, the mixture is added dropwise with stirring in 150 cm ^ ice water and extracted with chloroform 'after driving off the chloroform is obtained GOO mg 3'-0 ~ mesyl-5 ^l -chloro-5 ^l -deoxy-thymidine »melting point after recrystallization from ethanol 199 to 20O ⁰ C.

To a solution of 480 mg ^ '- O-mesyl - ^' - chloro-S '

'3

oxythymidine in 25 cm of boiling water are added in portions aqueous ethanolic triethylamine until the ρττ value remains unchanged (see Example 1), flat the cooling is concentrated in vacuo to dryness, the residue is added several times absolute ethanol and distilled off again in vacuo , The solid crude product is purified on a column of 50 g of silica gel H (Merck) with n-propanol / water (8: 2) as eluent. From fractions 38-55 (5 cm each), after concentration in vacuo, 260 mg ^ 2,3 ^t -Anhydro-1- (2 ^t , 5 ^l -didesoxy-5 ^l -chloro-.beta.-D-xylofuranosyl) -thamine. Melting point after recrystallization from 90% ethanol 218 to 221 ⁰ C *

-Λ4-      ''

148 813

312 mg of 2,3 * anhydro-1- (2% y-dideoxy-5- ^t- chloro-β-D-xylofuranosyl) -thymine- oχιά 312 mg of AlF-, are mixed with 125 cc

0.1 % HF in dioxane heated to 150 ° C for 2 hours. The β ^

The work-up is carried out as in Example 1. The syrupy residue is purified on 100 g of silica gel H (Merck) (column diameter 5 cm) with chloroform as eluent. The fractions 38-58 (10 cm each) contain 3 ^f , 5 ^! -Didoxy ~ 3 ^l -fluoro-5 ^l- chloro-thymidine.Iter syrupy residue of the concentrated in vacuo fractions is repeatedly taken up with ethanol and acetone and each again concentrated. Finally, it is mixed several times with a little petroleum ether and evaporated to dryness in vacuo. This results in a glassy foam yield of amorphous 3 '_>5'-dideoxy-3'-fluoro-5 ^l- chloro-thymidine 85 mg. R _Thymine on 0.25 mm silica gel thin layer with ethyl acetate / ethanol / water (4: 1: 2, upper phase): 1.40.

Editing game 6 . ·

3

500 mg of S'-chloro-S'-desoxythymidine are mixed with 0.63 cm of di-

, ο

ethyl (2-chloro-1,1,2-trifluoroethyl) amine in 5 cm of acetone for 30 minutes at 70 C (bath temperature). The work-up is carried out analogously to Example 2 by column chromatography on 100 g of silica gel (Merck) with n-propanol / V / as-

3 water (8: -2). In fractions 31-45 (8.5 de s) are 406 mg ^{2,3'-Anhydro-5-chloro-l} 5 ^t '-deoxy-thymidine. _e

UV absorption in water: ^ max 251 nm (έ 9950), λ. min 21 9.5 nm

(£, 6250).

The further reaction of the product with hydrogen fluoride in dioxane and the isolation of the formed 3 ¹ , 5'-dideoxy-5 ^f -chloro-3'-fluoro-tiiymidins takes place as in Example 5

Claims (3)

claims: 1 · Process for the preparation of cytostatic '2 ¹ , 3 *, 5'-trideoxy-3 *, 5 ^r -dihalogen-nucleosides of general formula I. X- Cfi _L ρ χ ^f in which X and X ^{1 are} halogen and P is a pyrimidine base having an on-structure at C-2, characterized in that the hydroxyl groups on C-3 ¹ and C ~ 5 ^f of 2'-I) are esoxy-nucleosides the general formula II HO-W ₁ ρ OH in which P has the abovementioned meaning, after activation, preferably by mesylation or tosylation, directly (C-5 ^f ) or exchanged after intervening intramolecular 2,3'-Anhydronucleosidbildung (C-3 ¹ ) successively against halogen. 2. A process for the preparation of 2 ·, 3 ', 5 ^f -Tridesoxy-5 ^l fluoro-3 ^f -halogen-nucleosides according to claim 1, characterized in that 2 ^l - _! Desoxyribonueleoside II are selectively mesylated or tosylated in the 5'-position in a known manner in the 5'-position, the S'-sulphonyloxy group having -AH- a fluoride, preferably potassium fluoride or tetrabutylammonium fluoride is exchanged, the formed KLuorverbindung by reaction with diethyl.l- (2-chloro-1,1,2-trifluoro-ethyl) -amine or by mesylation of the 3'-hydroxy group and subsequent alkali treatment is converted into the 2,3'-anhydro-S'-deoxy-S'-fluorine nucleoside and then reacted preferably with a hydrogen halide to the 3'-halogen compound. 3 · Process for the 2, 3 ', S'-trideoxy-S'-fluoro-5 * -halogenonucleosides according to claim 1, characterized gekennzeiohn et, that 2'-deoxyribonucleosides II in a conventional manner in the 5'-position selectively be substituted or tosylated, the 5'-sulfonyloxy group with a halogen compound, preferably tetrabutylammonium halide or an alkali metal halide, is substituted by halogen, the halogeno compound formed by reaction with diethyl (2-chloro-1,1,2-trifluoroethyl) - amine or by mesylation of the 3'-hydroxy group and subsequent alkali treatment in the 2,3'-anhydro-S'-deoxy-S'-halogen ^ -nucleoside transferred and then reacted with EF to the 3'-Flu.orverbindung. '·