DK147302B - METHOD OF PREPARING 4-ALFA HYDROXY DERIVATIVES OF VINCA ALKALOIDS - Google Patents

Description

in 147302

The present invention relates to a process for the preparation of novel antimitotically active 4-des-acetoxy-4-k-hydroxy derivatives of Vinca alkaloids of the general formula V set forth in claim 1,

The so-called "Vinca alkaloids" have attained a considerable position as marketed or experimental chemotherapeutic agents for the treatment of carcinoma, sarcoma and leukemia cases. These agents can be used both alone and in combination with other oncolytic agents. By class, the Vinca alkaloids comprise compounds recoverable from the leaves of Vinca Rosea, derivatives made by chemical modification thereof, and dimeric alkaloids prepared by interconnecting the two "monomeric" portions of the Vinca alkaloid backbone by a modified Polonovski reaction (Langlois and Potier, Tetrahedron Letters, 1099, (1976), Potier et al., JCS Chem. Comm., 670, (1975),

Kutney et al., Heterocycles, 3, 205, (1975) and Atta-ur-Rahman, Tetrahedron Letters, 2351, (1976).

The majority of the known Vinca alkaloids can be characterized by the following formula: 2

/ V ° '<1 \ V'-rS

'7 ΓΠΡ.Γ 14 i | n

Η | ISLAND

i y r-la 7 * l '° 1 11 / \ V'A f ^ r'Vr Y'7'0 ^

Ni / 1 8 \ / V / ΐ Γ ***

Ra · C-O-CHa fl 0. 1. 2 3

When R in the above formula is acetoxy, R is methyl, R is hydroxyl, R 1 is ethyl and R 2 is H, the formula denotes vinblastine "12 3 4 (VLB). When R is acetoxy, R is formyl, R is hydroxyl, R is 5 l of ethyl and R is H, the formula denotes vineristin. When R is acetoxic, R is methyl, R is ethyl, R is hydroxyl and R is H, 1 2 denotes the formula leurosidine. When R is acetoxy, R is methyl, R 4 is R and R is H and R is ethyl, the formula denotes deoxy-VLB "A".

12 5 When R, R and R are the same as in deoxy-VLB "A" (4'-deoxy-4,4 vinblastine), while R is ethyl and R is hydrogen, the form represents. 1 2 len deoxy-VLB "B" (4'-deoxyleurosidine). When R is acetoxy, R 3 4 5 is methyl, R is ethyl and R and R together form a cl-apo-. 13 4 5 xid ring, the formula denotes leurosine. And when R, R, R and R are 2 the same as in leurosine, while R is formyl, the formula denotes leuroformin (N-formylleurosine).

The above alkaloids are described in the following publications: Leurosin (vinleurosine;

3 370 057). VLB (vincaleukoblastin, vinblastine; U.S. Patent No. 3,097,137), leurosidine (vinrosidine), and vineristin (leurocristine or VCR) (both U.S. Pat.

3,205,220), and deoxy-VLB "A" and "B", Tetrahedron Letters, 783 (1958). Other alkaloids available from vinca, rosea, include 4-desacetoxy-vinblastine (U.S. Pat.

3,954,773); 4-desacetoxy-3'-hydroxyvinblastine (U.S. Patent No. 3,944,554); leurocombin (2 * -hydroxy-VLB, U.S. Patent No. 3,890,325) and vincadioline (3'-hydroxy-VLB U.S. Patent No. 3,887,565).

Two of the above-mentioned alkaloids, VLB and vineristin, are now being negotiated as medicines for the treatment of certain malignant diseases, in particular leukemia diseases and similar diseases in humans. Of these marketed compounds, vineristin is the most effective and useful agent in the treatment of leukemia, but it is also the least prevalent of the antineoplastic alkaloids in Vinca rosea. U.S. Patent No. 3,899,493 (Jovanovics et al.) Discloses an excellent oxidative method for converting the alkaloid VLB, which occurs in larger amounts, into the winery pathway using chromic acid in acetone and acetic acid at about -60 ° C. The same method has been used to prepare leuroformin (N-formyl-leurosine) from leurosine (Belgian Patent Specification No. 811,110). Leuroformin is currently undergoing a clinical trial in Europe, specifically for the treatment of leukemia diseases and a number of myeloma diseases.

One of the known methods for chemical modification of VLB and vineristin involves hydrolysis of the 4-acetoxy group to obtain 4-desacetyl-VLB (DAVLB) or 4-desacetyl-vineristin (DAVCR). In these compounds, R 1 in Formula I is hydroxyl, and the compounds are thus 3-hydroxy-phosphorous bonds. These can be oxidized to 4-oxo derivatives by the vinca alkaloids, as described in the specification of Danish patent application No. 2029/82.

4 147302

It has now surprisingly been found that when the 4-oxo derivatives of vinca alkaloids are reduced under special conditions, 4-oC-hydroxy derivatives of vinca alkaloids are obtained. Accordingly, the process of the invention is characterized by reacting a compound of formula s' Ra

11 il I i19 'Ί RS

/ \, o \ \ y ~ R

, s: * ir% -1 14 i; n. » ! °! ° / '\! . · 1 ;: i J i <-VYV ..... ^ ch3o-! '"FTL J = o ^ 1 2 3 4 5 / \ 1 / w

"OH

l CH: 3 l C-G-CHa

II

Wherein R, R and R have the meanings set forth in claim 1, with LiAlH (t-butyloxy) 2 in a non-reactive anhydrous solvent, preferably dry tetrahydrofuran (THF) or diethyl ether, and isolating the compound formed in in the form of a free base or a pharmaceutically acceptable salt thereof, whereupon, if desired, a formed compound of the formula V shown in claim 1, wherein R represents CH 2, is oxidized with chromium trioxide. In this reaction, an excess of the reducing agent is usually used.

147302 5

The pharmaceutically acceptable acid addition salts of the above alkaloid bases can be formed with inorganic acids such as hydrochloric acid, nitric acid, phosphoric acid, sulfuric acid, hydrobromic acid, hydrogen iodide acid, nitric acid and phosphoric acid, as well as with organic acids such as aliphatic mono- and dicarboxylic acids, hydroxyalkanoic acids, hydroxyalkanoic acids, aromatic acids and aliphatic and aromatic sulfonic acids.

Such pharmaceutically acceptable salts thus include sulfates, pyrosulfates, bisulfates, sulfites, bisulfites, nitrates, phosphates, monohydrogen phosphates, dihydrogen phosphates, metaphosphates, pyrophosphates, chlorides, bromides, iodides, acetates, propionates, decanoates, caprylates, acrylates, formates, caprates, heptanoates, propiolates, oxalates, malonates, sucinates, suberates, sebacates, fumarates, maleates, benzoates, chlorobenzoates, methylbenzoates, dinitrobenzoates, hydroxybenzoates, methoxybenzoates, phthalates, terephenate sulfates, benzenesulfonates, benzenesulfonates benzenesulfonates, xylene sulfonates, phenylacetates, phenyl propionates, phenylbutyrates, citrates, lactates, 2-hydroxybutyrates, glycollates, malates, tartrates, methanesulfonates, propane sulfonates, naphthalene-1-sulfonates, naphthalene-2-sulfonates

The invention is further illustrated by the following examples. EXAMPLE 1

Preparation of 4-desacetoxy-4g-hydroxyquinblastine

A solution was prepared from 76.6 mg of 4-desacetoxy-4-oxovin blastin and 0.90 ml of anhydrous tetrahydrofuran (THF). All apparatus used to form the solution and carry out the reaction was dried in an oven. To the above solution was added 76.2 mg of LiAlH (t-BuO) 2. The reaction mixture was stirred at room temperature in a closed flask under nitrogen atmosphere for about 22 hours. A solution of 0.11 g of ammonium sulfate and 0.17 ml of water was added, then infusion soil was added and the reaction mixture was filtered through infusion soil. The filter cake was washed out with THF.

The clear colorless filtrate was concentrated in vacuo and the resulting evaporation residue containing 4-desacetoxy-4a-hydroxyvinblastine formed in the above reaction was dissolved in methylene chloride. Upon removal of the methylene chloride, 78.7 mg of a white solid was obtained, which by TLC was found to contain a single staining material. The residue was chromatographed over 20 g of silica gel (Woelm) using a mixture of benzene and chloroform (2: 1) containing 6, 9, 13.5, 20, 30 and 45 percent methanol and eluted with 30 ml portions. Fractions of volume 10 ml were taken, and fractions 7-12 were pooled to give, after evaporation of the solvents, 55.1 mg of a yellow solid which, by TLC, was found to contain single spot gift material. Recrystallization from ethanol gave 28.8 mg of fluffy white crystals. The 4-des-acetoxy-4a-hydroxyvinblastine thus prepared was found to have the following physical characteristics: 100 mHz pmr spectrum: δ (CO 15) 8.23 (bs, 1, indole NH), 7.43-7.61, ( m, 1, Cn-H), 7.01-7.22 (m, 3, C12, _14, -H), 6.59 (s, 1, Cl4-H), 6.05 (s, 1, C17-H), 5.66-5.77 (m, 2, C6 yH), 4.02 (d, J = 3.1, C4-H), 3.88 (s, 3, C15-OCH3) , 3.75 (s, 3, C 3 -CO 2 CH 3), 3.73 (bs, 1, C 2 -H), 3.59 (s, 3, C 18, -CO 2 CH 3), 2.85 (s, 3, N -CH3), 0.98 and 0.87 (2h, J = 7, 6, c21> 21! H).

Infrared spectrum: V (CHCl3) = 3465, 3005, 1724, 1616, 1500, 1458, 1432 cm -1.

147302 7

Ultraviolet spectrum: \ (EtOH) = 214 fe 4.46 x 10 4), 288, 296 nm.

Mass Spectrum: m / e 768 (M +), 737, 709, 651, 543, 154.

EXAMPLE 2

Preparation of 4-desacetoxy-4a-hydroxyquinristine

A solution of 76.8 mg of 4-desacetoxy-4oc-hydroxyvinblastine and 10 ml of acetone was prepared. 43.5 µl of an acidic solution prepared from 19.9 ml of water and 2.5 ml of 18M sulfuric acid were added, forming a fine precipitate immediately. This acidic mixture was cooled to about -60 ° C and an oxidizing solution containing 90 mg of chromium trioxide in 1 ml of glacial acetic acid and 0.1 ml of water was added dropwise over 4 minutes. The reaction mixture was stirred at -60 to -50 ° C for 20 minutes and then further cooled to -70 ° C.

2 ml of 14N aqueous ammonium hydroxide was added and the resulting mixture was poured into 50 ml of a mixture of ice and water. The aqueous phase was extracted three times with chloroform and the chloroform extracts were combined. These were washed out with dilute sodium bisulfite and then dried. Evaporation of the solvent gave 61.6 mg of a solid pale yellow residue. This residue was chromatographed over 20 g of silica gel (Woelm activity i). The chromatogram was developed with methylene chloride and ethyl acetate (1: 1) in 30 ml portions containing 4, 6, 9, 13.5, 20 and 30 percent methanol. Fractions of 10 ml were collected and fractions 15-20 were combined to give 34.8 g of a white solid consisting of 4-desacetoxy-4a-hydroxyvinocristine formed by the above reaction. The residue was dissolved in anhydrous ethanol and 124 μΐ of a 2% by volume solution of aqueous sulfuric acid in anhydrous ethanol was added to give the sulfate salt of 4-desacetoxy-4a-hydroxyvinblastine. The free base had the following physical characteristics:

Mass Spectrum: m / e 782 (M +), 751, 355, 154.

The compounds obtained according to the invention act as mitotic inhibitors in the ovaries of Chinese hamsters.

Specifically, 4-desacetoxy-4 <* - hydroxyvinblastine exhibits a mitotic inhibition that is substantially similar to the effect achieved with either vinblastine sulfate or 4-desacetylvinblastine, exhibiting effect at levels as low as 0.01 µg / ml.

The present compounds of formula V can be used as antitumor agents. They exhibit such an effect on transplanted tumors in mice. For this assay, a method was used which included intraperitoneal administration of the drug at a given dose level for 7 to 10 days after inoculation of the tumor or alternatively on the first, fifth and ninth day after inoculation.

The following table lists the results of a series of experiments in which transplanted tumors in mice were treated effectively by a compound of the invention.

The first column of the table lists the name of the compound, column 2 shows the transplanted tumor, column 3 lists the dose level and the number of days the dosing was performed, and column 4 shows the percent inhibition of tumor growth or, in that case. where the tumor is B16, the percentage extension of survival time. GLS is an abbreviation for Gordner lymphosarcoma, CA755 is an adenocarcinoma and Bl6 is a melanoma.

9 147302 α> Μ Η Φ

bO

in ti - H ~

O HH HH

<H HH. H

bO t

U bO bO tfl bO

4 ^ 4 cd cd X tJ cg hx) cq 'ΰ' ΰ w wd φ! Μ ti '”, Χ HO .id

ra o co tn ra o o σ> ω-W

bom -μίΝοο HOtn co -phcm · ηην h ra xσ> <χ> m X cviuo

• Η H f — w · she — s O O H

d φ [> —π— -μ tsc-c- -μ φ ΐ>

Χ3 φ bObObO bObObO

• HH cd cd cd «3 cg cd, cj Pi d d d 'H o o Hin uncle +> ocr \ m o o m

d <H H HH

Φ cd o o u

Ph φι bl „cd ooo o ooo H d hhh mmm h hhh mmm

j | X XXX XXX X XXH XXX

H bc ootn ooo o oom ooo ^ «I (S« V * t * k «« * »V ·. Λ · * λ Λ s votnn cnvom m vo tnn nvoto bl il SL,

o CQ VO tn CQ VQ

JJ H tn H H

O PQ IN O FQ

Φ d

Pi Φ I I>

(f S · S

OO Pi ti ti g fe fe oi? +> Haa tf cd "T" f H ti φ ^ I ^ Éq 03 ra o β o pi -µ Η * µ · Η -µ · Η fi Φ φ .µ Φ +3 Φ d ο ra ο ra -μ ΰ cd cd cd · Η ω • Η ΜΗ Φ ρ, φ Ρ Φ, Ω Φ ϋ U τ) ΰ xf Pi b Ο I Η I · Η Ρ4> <t »> Ή 147302 ίο

Using the novel compounds obtained according to the invention as antitumor agents, either parenteral or oral administration can be used. For oral dosing, a suitable amount of a pharmaceutically acceptable salt of a base of formula V is used and formed with a non-toxic acid (e.g., the sulfate salt), and the salt is mixed with starch or with another excipient, after which the mixture is placed in telescopic gelatin capsules, each containing from 7.5 to 50 mg of active compound. Similarly, the anti-neoplastic active salt can be mixed with starch, a binder and a lubricant and then pressed into tablets, each containing from 7.5 to 50 mg of salt. The tablets can be scratched so that they can be split if lower or divided dosages are to be used. However, parenteral administration is preferred. For this purpose, isotonic solutions containing 1-10 mg / ml of a salt of a vinca alkaloid derivative of formula V, e.g. sulfate. The compounds are administered in doses of between 0.01 and 1 mg per day. and preferably from 0.1 to 1 mg per kg. kg body weight once or twice a week or every other week, depending on both the effect and the toxicity of the drug. An alternative method of arriving at a therapeutic dose may be based on the surface area of the body by administering doses of between 0.1 and 10 mg 2 per day. m body surface every 7 or 14 days.

Claims (2)

147302 A process for the preparation of 4-a-hydroxy derivatives of Vinca alkaloids of the general formula 'R3 / \ °' k 'f-CO-CH3 14 1 J11 H j 0 i »A« 1 2 3 4j αΛΑ / .... / 't, s st ....... 013 CHs0-l'e 1 .L * 1-. η H% \ / \! / · N% OH I · OH R2 · • C-OCH, v II 3 0 2 5 wherein R represents CH, or CHO; R represents H, and one of the 3 J 4 substituents R and R represents OH or H, while the other 2 represents C 2 H 5; R and R taken together represent 3 an epoxide ring, while R 3 is C 2 H 5; or pharmaceutically acceptable salts thereof, characterized in that a compound of the formula is reacted