JP2587705B2 - 4-desoxy-4-epipodophyllotoxin derivatives - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a novel 4-desoxy-4-epipodophyllotoxin derivative having antitumor activity and useful as an antitumor agent.

2. Description of the Related Art Podophyllotoxin derivatives having antitumor activity have been known for a long time, and typical compounds thereof include etoposide, teniposide and the like. But side effects,
Due to clinical problems, fully satisfactory compounds have not yet been obtained.

Problems to be Solved by the Invention An object of the present invention is to provide a compound having excellent antitumor activity and useful as a therapeutic agent for tumors.

The present inventors have conducted intensive studies on podophyllotoxin derivatives, and as a result, found a compound having extremely strong antitumor activity and completed the present invention.

Means for Solving the Problems The present invention relates to a 4-desoxy-4-epipodophyllotoxin derivative represented by the following general formula (I).

[In the formula, R ¹ represents a hydrogen atom or a methyl group, and R represents a lower alkenyl group or a lower alkyl group which may have a hydroxyl group or an acetoxy group as a substituent. The compound of the present invention represented by the general formula (I) has excellent antitumor activity and is effective for treating various tumors.

Examples of the lower alkenyl group represented by R in the above general formula (I) include a vinyl group, a 1-propenyl group, an isopropenyl group, an allyl group, a 2-butenyl group and a 2-methyl-2.
Examples thereof include linear or branched alkenyl groups having 2 to 6 carbon atoms, such as -butenyl, 3-pentenyl, and 4-hexenyl groups. Examples of the lower alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a hexyl group. And 6 linear or branched alkyl groups. Examples of the lower alkyl group having a hydroxyl group include a hydroxymethyl group, a 2-hydroxyethyl group,
-Hydroxypropyl group, 3-hydroxypropyl group,
1,3-dihydroxypropyl, 2,3-dihydroxybutyl, 2,3-dihydroxypentyl, 2,3-dihydroxyhexyl, etc.
6 is a lower alkyl group having an acetoxy group, wherein the lower alkyl group having an acetoxy group includes an acetoxymethyl group, a 2-acetoxyethyl group, a 2-acetoxypropyl group, a 3-acetoxypropyl group, C1-C6 straight chain containing one or two acetoxy groups such as diacetoxypropyl, 2,3-diacetoxybutyl, 2,3-diacetoxypentyl, and 2,3-diacetoxyhexyl Alternatively, a branched alkyl group can be exemplified.

The 4-desoxy-4-epipodophyllotoxin derivative of the present invention can be produced, for example, according to the following reaction scheme 1.

Wherein R ¹ is a hydrogen atom or a methyl group, R ² is a lower alkenyl group, R ³ is a lower alkyl group, R ⁴ is a lower alkyl group having a hydroxyl group, and R ⁵ is a lower alkyl group having an acetoxy group. Is shown. Hereinafter, each step of the above reaction formula will be described.

<Step A> By reacting 4-epipodophyllotoxin represented by the general formula (II) with lower alkenylsilane represented by the general formula (III) in a suitable solvent in the presence of a Lewis acid, I) The target compound (Ia) in which R is a lower alkenyl group is obtained. The solvent is not particularly limited as long as it does not participate in the reaction, for example, dichloromethane,
Aprotic solvents such as chloroform, 1,2-dichloroethane, tetrahydrofuran, dioxane and the like can be used.
As the Lewis acid, for example, titanium tetrachloride, trimethylsilyltrifluoromethanesulfonate, zinc bromide, boron trifluoride ethyl ether and the like can be used. The reaction ratio is such that the compound of the general formula (III) is 1 to 5 times the molar amount of the compound of the general formula (II), and the Lewis acid is the compound of the general formula (II).
It is preferable to use 0.5 to 3 times the molar amount. The reaction is carried out at a temperature of -100 to 100C, preferably -20 to 20C.

<Step B> The derivative represented by the general formula (Ia) obtained in the step A is catalytically reduced in an inert solvent in the presence of a catalyst, whereby R in the general formula (I) is a lower alkyl group. The desired compound (Ib) is obtained. As the solvent, for example, ethyl acetate,
Methanol, tetrahydrofuran or the like can be used alone or in combination. As the catalyst, for example, palladium black, platinum or the like can be used. The hydrogen pressure is from normal pressure to 3 atm, preferably from normal pressure to 2 atm. The reaction temperature is 0 to 40 ° C, preferably room temperature.

<Step C> The derivative represented by the general formula (I) obtained in the step A is oxidized in an inert solvent to give R in the general formula (I).
Is a lower alkyl group having a hydroxyl group to obtain the desired compound (Ic). As the solvent, for example, carbon tetrachloride, acetonitrile, acetic acid, water, pyridine and the like can be used alone or as a mixture. As the oxidizing agent, for example, ruthenium oxide, sodium periodate, osmium tetroxide and the like can be used. The reaction rate is preferably such that the oxidizing agent is used in an amount of 0.1 to 2 moles per mole of the compound of the formula (Ia). The reaction temperature is -10 to 80C, preferably 0 to 20C.

<Step D> The derivative represented by the general formula (Ic) obtained in the step C is acetylated in an inert solvent in the presence of a base, whereby R in the general formula (I) has an acetoxy group. The target compound (Id) which is an alkyl group is obtained. As the solvent, for example, benzene, tetrahydrofuran, dichloromethane and the like can be used. As the base, for example, pyridine,
Dimethylaminopyridine, imidazole and the like can be used. As the acetylating agent, acetyl chloride, acetic anhydride and the like can be used. The reaction rate is preferably 1 to 3 times the molar amount of the acetylating agent and 0.1 to 3 times the molar amount of the base, based on the compound of the formula (Ic). The reaction temperature is 0-60 ° C, preferably 0-20 ° C.

The compound obtained in step D compound wherein R ¹ is hydrogen atom in (I d) is hydrolyzed by a conventional ester cleavage reaction, that R ¹ of the compound (I c) to obtain a compound of hydrogen atoms it can.

Compounds (Ia), (Ib), (I
Of the compounds (c) and (Id), the compound in which R ¹ is a methyl group can be easily converted to the compound of the present invention in which R ¹ is a hydrogen atom by a usual demethylation reaction.

Compounds (Ia), (Ib),
(Ic) and (Id) are isolated and purified by means usually used in the art, such as concentration, filtration, recrystallization, and various types of chromatography.

Examples Examples will be given below to explain the present invention in more detail.

Example 1 Synthesis of 4-tesoxy-4-allyl-4-epipodophyllotoxin (compound 1) 274 mg of trimethylallylsilane in a solution of 500 mg (1.2 mmol) of 4-epipodophyllotoxin in 10 ml of dichloromethane
(2.4 mmol) and cooled to -10 to 0 ° C. 350 μL of boron trifluoride ethyl ether was added to this solution and stirred for 4 hours. After the reaction, 350 μm of pyridine was added, and the mixture was extracted with ethyl acetate. The organic layer was dried and distilled off. The residue was purified by column chromatography (silica 50 g, developing solvent; ethyl acetate: n-hexane = 1: 2), crystallized from ether and n-hexane, and collected by filtration. -Desoxy-4-allyl-4-epopidophyllotoxin (compound 1) (450 mg, yield 81.1)
%)Obtained.

Melting point 93-95 ° C ▲ [α] ²⁰ _D ▼ = -85.20 (C = 0.500, CHCl ₃ ) ¹ H-NMR δ ppm (CDCl ₃ ) 6.73 (1H, s, 5-position H), 6.46 (1H, s, 8) H), 6.29 (2H, s,
2 ', 6'-position H), _{5.48-5.80 (1H, m, -CH 2} CH = CH 2), 4.88-5.20 (2H, m,
−CH = CH ₂ ), 4.52 (1H, d, J = 3.6 Hz, first place H), 3.78 (3H, s, OCH ₃ ), 3.74 (6H, s, OCH ₃ × 2), 2.80-3.40
(3H, m, 2, 3, 4 H), 2.24-2.60 (2H, m , -CH 2 CH
= CH ₂ ) Example 2 Synthesis of 4-desoxy-4- (1-propyl) -4-epopidophyllotoxin (Compound 2) 4-Desoxy-4-allyl-4-epipod obtained in Example 1 100 mg (0.23 mmol) of phyllotoxin ethyl acetate:
10% of 5% palladium on carbon in 10 ml of methanol (1: 1) solution
, And the catalytic reduction was carried out in a stream of hydrogen (one burst). After the reaction, 5% palladium carbon was removed by filtration, and the filtrate was concentrated under reduced pressure. The obtained residue was crystallized from ether and n-hexane, collected by filtration and 4-desoxy-4- (1-propyl).
80 mg (yield 79.7%) of -4-epipodophyllotoxin (compound 2) was obtained.

Melting point 114-115 ° C ▲ [α] ²⁰ _D ▼ = -74.28 (C = 0.520, CHCl ₃ ) ¹ H-NMR δ ppm (CDCl ₃ ) 6.69 (1H, s, 5-position H), 6.45 (1H, s, 8) H), 6.28 (2H, s,
2 ', 6'-position H), 4.57 (1H, m, 1st H), 3.79 (3H, s, OCH ₃ ), 3.74 (6H, s, OCH ₃ × 2), 2.80-3.20
(3H, m, 2, 3, 4 H), 1.20-1.80 (4H, m , -CH 2 CH 2 CH
_{3), 0.98 (3H, t} , J = 6.1Hz, -CH 3) Example 3 4-desoxy-4'-demethyl-4- (1-propyl)
Synthesis of 4-epipodwillotoxin (compound 3) 4-desoxy-4- (1-propyl) obtained in Example 2
-4- Epipodophyllotoxin 80 mg (0.18 mmol) 1,2
1 ml of 25% hydrogen bromide / acetic acid in 5 ml of dichloroethane solution
Was added and stirred at room temperature for 15 hours. After the reaction, the solution was distilled off, and the obtained residue was purified by column chromatography (silica; 50 g, developing solvent; ethyl acetate: n-hexane = 1: 4), and crystallized from ether and n-hexane. And collected by filtration to obtain 55 mg of 4-desoxy-4'-demethyl-4- (1-propyl) -4-epipodophyllotoxin (compound 3).
(71.7% yield).

Melting point 189-191 ° C ▲ [α] ²⁰ _D ▼ = −78.03 (C = 0.346, CHCl ₃ ) ¹ H-NMR δppm (CDCl ₃ ) 6.69 (1H, s, 5-position H), 6.45 (1H, s, 8) H), 6.29 (2
H, s, 2 ', 6'H), 5.41 (1H, s, -CH), 4.57 (1H, m, 1st H), 3.77 (6H, s, OCH ₃ × 2), 2.80-3.20 (3H, m, 2nd, 3rd, 4th H), 1.20-1.80 (4H, m, -CH ₂ CH ₂ CH ₃ ), 0.98 ( 3H, t, J =
5.9 Hz, -CH ₃₎ obtained in Example 4 4- desoxy-4- (2,3-dihydroxy-1-propyl) -4-epi-podophyllotoxin Synthesis Example 1 of toxin (Compound 4) 4- desoxy Solution of 100 mg (0.23 mmol) of -4-allyl-4-epipodophyllotoxin in pyridine 2
58 mg (0.23 mmol) of osmium tetroxide was added to the ml, and the mixture was stirred at room temperature for 1 hour. A reaction trace, a hydrous pyridine solution of 0.1 g of sodium bisulfite was added, and the mixture was stirred for 30 minutes. The reaction mixture was extracted with ethyl acetate, washed with diluted hydrochloric acid and water, and dried. After concentrating the organic layer, the obtained residue was purified by column chromatography (silica; 50 g, developing solvent: chloroform: methanol = 20: 1). The residue obtained by concentration was crystallized from ether and n-hexane, and collected by filtration.
Desoxy-4- (2,3-dihydroxy-1-propyl)
97 mg (yield 89.3%) of -4- epipodophyllotoxin (compound 4) was obtained.

144-145 ° C ▲ [α] ²⁰ _D ▼ = -73.42 (C = 0.520, CHCl ₃ ) ¹ H-NMR δ ppm (CDCl ₃ ) 6.87,6.80 (1H, s, 5-position H), 6.44,6.42 (1H , s, 8th H), 6.
28,6.26 (1H, s, 2 ', 6'-position H), 4.53 (1H, m, 1st H), 3.79 (3H, s, OCH ₃ ), 3.73 (6H, s, OCH ₃ × 2), 3.58-3.68
(1H, m, -CH (OH ) CH 2 OH), 3.24-3.58 (2H, m, -CH (O
_{H) CH 2 OH), 2.60-3.24} (5H, m, 2 , 3, 4 H, -CH (O
_{H) CH 2 OH), 1.28-2.00} (2H, m, -CH 2 CH (OH) CH 2 OH) Example 5 4- desoxy-4- (2,3-diacetoxy-1-propyl) -4-epi Synthesis of podophyllotoxin (compound 5) 4-desoxy-4- (2,3-dihydroxy-1-propyl) -4-epipodophyllotoxin 90 obtained in Example 4
428 mg (4.19 mmol) of acetic anhydride and 10 mg of dimethylaminopyridine were added to 5 ml of a 0 mg (1.90 mmol) tetrahydrofuran solution.
Was added and stirred at room temperature for 2 days. After the reaction, diluted hydrochloric acid was added, and the mixture was extracted with ethyl acetate. The organic layer was washed with brine and water, and then dried. The residue obtained by distilling off the solvent was purified by column chromatography (silica; 50 g, developing solvent: chloroform: methanol = 50: 1). The residue obtained by concentration was crystallized from ether and n-hexane, collected by filtration, and treated with 4-desoxy-4- (2,3-diacetoxy-1-).
Propyl) -4-epipodophyllotoxin (compound 5)
927 mg (87.7% yield).

Melting point 92-93 ° C ▲ [α] ²⁰ _D ▼ = -52.52 (C = 0.495, CHCl ₃ ) ¹ H-NMR δ ppm (CDCl ₃ ) 6.65 (1H, s, 5-position H), 6.45 (1H, s, 8) H), 6.26 (2H, s,
2 ', 6'-position H), 4.80-5.40 (1H, b, -CH ( OAc) CH 2 OAc), 4.54 (1H, m, 1
H), 3.79 (3H, s, OCH ₃ ), 3.74 (6H, s, OCH ₃ × 2), 2.80-3.20
(3H, m, 2nd, 3rd, 4th H), 2.20,2.12,2.11,2.08 (6H, s,
_{-OCOCH 3), 1.68-2.00 (2H,} m, -CH 2 CH (OAc) -) Example 6 4- desoxy-4'-demethyl-4-allyl-4-epipodophyllotoxin (Compound 6) Synthesis 4'-demethyl-4-epipodophyllotoxin 100mg
To a solution of (0.25 mmol) in 2.5 ml of dichloromethane was added 60 mg (0.53 mmol) of trimethylallylsilane, and the mixture was cooled to -20 to 0 ° C. To this solution, add boron trifluoride ethyl ether 74μ.
Was added and stirred for 3 hours. After the reaction, 74 μm of pyridine was added, and the mixture was extracted with ethyl acetate. The organic layer is evaporated after drying.
After purification by column chromatography (silica; 50 g, developing solvent; ethyl acetate: n-hexane = 3: 2), the product was crystallized from diethyl ether, collected by filtration, and 4-desoxy-4'-demethyl-4-allyl. 52 mg (yield 49.1%) of -4- epipodophyllotoxin (compound 6) was obtained.

Melting point 181-182 ° C (decomposition) ▲ [α] ²⁰ _D ▼ = -90.94 (C = 0.552, CHCl ₃ ) ¹ H-NMR δ ppm (CDCl ₃ ) 6.72 (1H, s, 5-position H), 6.47 (1H, s, 8th H), 6.29 (2H, s,
2 ', 6'-position H), _{5.60-5.87 (1H, m, -CH 2} CH = CH 2), 5.41 (1H, s, 4 ' position O
H), 5.03-5.20 (2H, m , -CH = CH 2), 4.55 (1H, d, J = 4.8
Hz, 1st H), 4.29, 2.87−3.44 (3H, m, 2nd, 3rd, 4th H), 2.34−2.77 (2H, m,
Synthesis Example of -CH ₂ CH = CH ₂₎ Example 7 4- desoxy-4'-demethyl-4- (2,3-diacetoxy-1-propyl) -4-epipodophyllotoxin (Compound 7) 5 4-Desoxy-4- (2,3-diacetoxy-n-propyl) -4-epipodophyllotoxin 50 obtained in
0 mg (0.90 mmol) was dissolved in a mixture of 1,2-dichloroethane (12 ml) and diethyl ether (1 ml), 1 ml of 25% hydrogen bromide / acetic acid was added, and the mixture was stirred at room temperature for 20 hours. After the reaction,
After extraction with a mixture of a 1% aqueous sodium hydrogen carbonate solution and ethyl acetate, the extract was washed with water and dried. The solvent was distilled off, and the obtained residue was purified by column chromatography (silica; 50 g, developing solvent: chloroform: methanol = 30: 1). The residue obtained by concentration was crystallized from ether, collected by filtration, and 4-desoxy-4-demethyl-4- (2,3-diacetoxy-1-propyl) -4-epipodophyllotoxin ( 150 mg (yield 30.7%) of compound 7) was obtained.

Melting point 169-170 ° C ▲ [α] ²⁰ _D ▼ = -106.25 (C = 0.448, CHCl ₃ ) ¹ H-NMR δ ppm (CDCl ₃ ) 6.65 (1H, s, 5-position H), 6.45 (1H, s, 8) H), 6.28 (2H, s,
2 ', 6'-position H), 5.44 (1H, s, OH) , 4.72-5.40 (1H, b, -CH (OAc) CH 2 OA
c), 4.53 (1H, m, 1st H), 3.77 (6H, s, OCH ₃ × 2), 2.60−3.20 (3H, m, 2nd, 3rd, 4th H), 2.20,2.12,2.11,2.08 (6H, s, −OCOCH ₃ ), 1.48− 2.
_{00 (2H, m, -CH 2} CH (OAc) -) Example 8 4-desoxy-4'-demethyl-4- (2,3-dihydroxy-1-propyl) -4-epipodophyllotoxin (Compound Synthesis of 8) 4-Desoxy-4'-demethyl-4- obtained in Example 7
5 ml of a methanol solution of 100 mg (0.18 mmol) of (2,3-diacetoxy-1-propyl) -4-epipodophyllotoxin
To the mixture was added 30 mg (0.16 mmol) of zinc acetate, and the mixture was stirred under reflux for 6 hours. After the reaction, column chromatography (silica; 50 g,
Purified with a developing solvent; chloroform: methanol = 15: 1). The residue obtained by concentration is crystallized from ether,
It was collected by filtration and 4-desoxy-4'-demethyl-4- (2,3-
60 mg (yield 72.8%) of dihydroxy-1-propyl) -4-epipodophyllotoxin (compound 8) was obtained.

131-133 ° C. ▲ [α] ²⁰ _D ▼ = −74.53 (C = 0.530, CHCl ₃ ) ¹ H-NMR δ ppm (CDCl ₃ ) 6.87,6.80 (1H, s, 5-position H), 6.43,6.42 (1H , s, 8th H), 6.
27,6.26 (1H, s, 2 ', 6'-position H), 5.41 (1H, s, 4'-OH), 4.53 (1H, m, 1H), 3.73 (6H, s, OCH ₃ × 2), 3.58-3.68 (1H, m, -CH (OH) C
_{H 2 OH), 3.24-3.58 (2H} , m, -CH (OH) CH 2 OH), 2.60-3.
24 (5H, m, 2, 3, 4 _{H, -CH (OH) CH 2} OH), 1.28-2.00
(2H, m, -CH ₂ CH (OH) CH ₂ OH) Pharmacological test P388 cells and S180 cells were each 2 × 10 ³ cells / weld
1, 5 × 10 ³ cells / well were seeded on a 24-well plate, and then contacted with the drug. The drug was dissolved in dimethyl sulfoxide and then diluted so that the final concentration of dimethyl sulfoxide was 0.1% or less. After 4 days of continuous contact, the number of viable cells was counted with a hemocytometer. The growth inhibition rate was calculated by the following equation, representing the drug concentration showing 50% growth inhibition as ED ₅₀ values.

The results are shown in Table 1.

Continued on the front page (72) Inventor Setsuo Takeda 1624-6 Ishii, Ishii-cho, Ishii-cho, Meishi, Tokushima (72) Inventor Viezyba Constanty 41-2 Shinkawaya, Kitamura, Kitajima-cho, Itano-gun, Tokushima (72) Inventor Small Takashi Takeuchi 463-10 Kagasuno, Kawauchi Town, Tokushima City, Tokushima Prefecture

Claims (1)

(57) [Claims] (1) General formula [In the formula, R ¹ represents a hydrogen atom or a methyl group, and R represents a lower alkenyl group or a lower alkyl group which may have a hydroxyl group or an acetoxy group as a substituent. 4- represented by
Desoxy-4-epipodophyllotoxin derivatives.