JPH0368033B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to novel camptothecin derivatives. More specifically, the present invention relates to the general formula (In the formula, R ¹ is a hydrogen atom or a carbon atom of 1 to
4, where X represents a substituted or unsubstituted piperidine ring or a substituted or unsubstituted piperazine ring) and an ammonium salt thereof.

Camptothecin is an alkaloid extracted and isolated from plants such as Camptothecaacuminata Nyssaceae, and has a strong effect of inhibiting nucleic acid synthesis.Its action is rapid and reversible, and has cross-resistance with existing anticancer drugs. It is an antitumor substance with a unique mechanism of action that does not show
Although it has been recognized to have a strong anticancer effect on experimentally transplanted cancers such as 256 sarcoma, its usefulness as a drug is currently limited due to its toxic effects.

The present inventors have so far made numerous attempts to obtain new camptothecin derivatives with improved pharmacological activity and toxicity by chemically modifying natural camptothecin. As a result, they found that the activity was enhanced by introducing an alkyl group into the 7-position (JP-A-Show
56-158786 and Japanese Patent Application Laid-Open No. 57-116015).

In addition, the present inventors have previously succeeded in synthesizing a 9-substituted camptothecin derivative containing 9-hydroxycamptothecin via 9-nitrocamptothecin (see JP-A-59-51289).

The present inventors further succeeded in introducing a hydroxyl group into the 9-position using a 7-lower alkylcamptothecin derivative as a starting material, and
Since this 9-hydroxyl compound is sparingly soluble in water, we succeeded in converting the hydroxyl group at the 9-position to a carbamoyloxy group to obtain a water-soluble derivative in consideration of its application as a medicine.

Therefore, the present invention provides, as novel camptothecin derivatives, carbamyloxy derivatives at the 9-position of 7-lower alkylcamptothecin and chlorocarbonyloxy derivatives at the 9-position as intermediates thereof.

The novel camptothecin derivative of the present invention can be produced as follows.

By treating 9-hydroxycamptothecin or 7-lower alkyl-9-hydroxycamptothecin with phosgene ( _COCl2 ), they can be converted to 9-hydroxycamptothecin or 7-lower alkyl-9-hydroxycamptothecin.
-Chlorocarbonyloxy derivative (X of the above general formula
is a chlorine atom), and the 9-chlorocarbonyloxy derivative is then reacted with the corresponding piperidine compound or piperazine compound. Moreover, this 9-aminocarbonyloxy derivative can be obtained by treating the above-mentioned 7-lower alkyl-9-hydroxycamptothecin or 9-hydroxycamptothecin with the corresponding above-mentioned piperidine compound or chloroformic acid amide derivative of the piperazine compound. can also be synthesized.

In particular, in the piperidine compound or piperazine compound described above, an ammonium salt can be formed with an inorganic acid or an organic acid at the N atom of the amino group, and since such an ammonium salt is water-soluble, it can be used as a medicine. It has significant useful advantages when administered.

Conventionally, one known method for making camptothecin derivatives water-soluble is to open the E ring (lactone ring) to form a sodium salt of a carboxylic acid. However, it has the disadvantage that it is weakened to a fraction of what it is.

The water-soluble salt as the ammonium salt is E
Although the ring structure remains intact without opening, it is easily converted into a 9-hydroxy (free form) form in vivo by the action of enzymes such as carboxamidase. It is considered to be something that can be obtained.

The novel camptothecin derivative and the method for producing the same according to the present invention will be explained in detail below.

The novel camptothecin derivatives of the present invention are 9-
By treating hydroxycamptothecin or 7-lower alkyl-9-hydroxycamptothecin with phosgene, it is converted into its 9-chlorocarbonyloxy derivative (a compound in which X in the above general formula is a chlorine atom), and the 9-chloro Carbonyloxy derivatives can then be prepared by reacting with various amines, but starting materials 9-hydroxycamptothecin or 7-lower alkyl-
9-Hydroxycamptothecin can be produced as follows. Camptothecin or 7-
Dissolve lower alkyl camptothecin in concentrated sulfuric acid,
While cooling on ice, slowly add concentrated nitric acid in an amount several times equivalent to camptothecin or 7-lower alkylcamptothecin, and then stir at room temperature.
The reaction is complete in 24-72 hours. Pour the reaction solution into several times the amount of water and extract several times with chloroform. After drying this chloroform layer over anhydrous magnesium sulfate, the solvent was dried to dryness under reduced pressure, and the residue was separated and purified using about 100 times the amount of silica gel column chromatography (chloroform). Nitrocamptothecin or 7-lower alkyl-9-
Nitrocamptothecin is obtained. These 9-
The nitro group is converted to an amino group by reducing or catalytically reducing the nitro compound using a metal such as iron or tin in hydrochloric acid. Thereby, the corresponding 9-amino compound can be obtained quantitatively. These 9-amino bodies were diazotized in an aqueous sulfuric acid solution,
By then heating, the 9-hydroxy form, that is, 9-hydroxycamptothecin or 7-lower alkyl-9-hydroxycamptothecin can be produced (see JP-A-59-51287 and JP-A-59-51289). .

Using this starting material, 9-hydroxycamptothecin or 7-lower alkyl-9-hydroxycamptothecin, the reaction operation is carried out as follows.

First, these 9-hydroxycamptothecin bodies are suspended in a dry solvent (eg, dioxane, acetone, etc.), and a small excess of phosgene gas is introduced into the suspension while stirring at room temperature. At this time, if a small excess of triethylamine is added, the reaction proceeds rapidly.
After confirming the disappearance of the raw materials using TLC or the like, insoluble matter is removed by filtration, and the liquid is dried under reduced pressure to quantitatively obtain 9-chlorocarbonyloxy compound as a pale yellowish white powder.

Next, this chlorocarbonyloxy compound is suspended in a solvent (e.g. dioxane, acetone, chloroform, methanol), a piperidine compound or a piperazine compound is added thereto, the reaction is carried out without heating or with heating, and the reaction mixture is subjected to chromatography. Purify with etc. In this way, a 9-aminocarbonyloxy compound is obtained.

Among the 9-aminocarbonyloxy compounds obtained in this way, those having an amino group in the 9-position side chain can be converted into water-soluble ammonium salts by treating them with an equal amount of acid (hydrochloric acid, acetic acid, etc.). I can do it.

Furthermore, the 9-piperazinocarbonyloxy compound obtained by the above synthesis method can be further treated with an appropriate alkylating agent to lead to the 9-(4-alkyl-1-piperazino)carbonyloxy compound. can.

The novel camptothecin derivatives provided by the present invention are useful compounds for use as antitumor substances, pharmaceuticals, and intermediates thereof.

Examples of the present invention are listed below.

Example 1 9-chlorocarbonyloxy-7-propylcamptothecin (A) 9-methoxycamptothecin (1.00 g,
2.65 mmol) was suspended in water (20 ml), concentrated sulfuric acid (approximately 10 ml) was added until methoxycamptothecin was dissolved, and after cooling in an ice bath, butyryl aldehyde (0.5 ml, 5.2 mmol) and FeSO ₄ 7H _{2 were} suspended. O(200
mg, 0.7 mmol), and 30% hydrogen peroxide solution (1.25 ml, 9.3 mmol) was added dropwise with stirring while cooling in an ice bath. After further stirring at room temperature for 12 hours, the reaction solution was poured into cold water (1). The resulting insoluble matter was extracted with chloroform,
The chloroform layer was separated, washed with water, dried over anhydrous magnesium sulfate, filtered, and dried under reduced pressure. The residue was recrystallized with ethanol and 520 mg
(46.7%) of 9-methoxy-7-propylcamptothecin in pale yellow needle-like crystals were obtained.

MP276-278℃ (decomposition) [EtOH] MS m/e: 420 [M ⁺ ] Elemental analysis value (as C ₂₄ H ₂₄ N ₂ O ₅ ) Calculated value C68.56, H5.75, N6.66 Actual value C68 .46, H5.70, N6.80 (B) 9-methoxy-7-propylcamptothecin (500 mg, 1.2 mmol) in 47% hydrogen bromide water (5 ml)
and heated to 140° C. for 8 hours with stirring. The reaction solution was poured into cold water (1), and the precipitate was collected by suction filtration and recrystallized from ethanol to obtain 200 mg (41.1%) of pale yellow needle-like crystals of 9-hydroxy-7-propylcamptothecin.

MP280℃ Elemental analysis value (as C ₂₃ H ₂₂ N ₂ O ₅ ) Calculated value C67.96, H5.46, N6.89 Actual value C67.77, H5.30, N6.99 (C) 9-Hydroxy-7 - Propylcamptothecin (100mg, 0.246mmol) was suspended in dry dioxane (150ml) and triethylamine (400μ
) was added and gently heated to dissolve. After cooling this to room temperature, phosgene dimer (trichloromethoxychloroformate) (100μ)
The mixture was stirred at room temperature for 30 minutes while introducing phosgene prepared at the time of use by decomposing the mixture under activated carbon catalyst. TLC (10% methanol-
After checking with chloroform (365 nm), the insoluble material was removed, the solvent was distilled off under reduced pressure, washed with a small amount of dry dioxane, and dried again under reduced pressure to obtain the title compound as a white powder (108 mg, 94% )
was gotten.

IRν ^KBr _nax cm ^-1 : 2970, 2920, 1770, 1655, 1590,
1500, 1220, 1170 Example 2 9-[4-(isopropylcarbamoylmethyl)
-1-piperazino]-carbonyloxycamptothecin 9-hydroxycamptothecin (190mg,
0.521 mmol) and 1-chlorocarbonyl-4-(isopropylcarbamoylmethyl)piperazine (257 mg, 1.04 mmol) were dissolved in anhydrous pyridine (12 ml) and stirred at room temperature for 4.5 hours. Then, the solvent was distilled off under reduced pressure, and the residue was dissolved in chloroform (100 ml).
dissolved in. This chloroform solution was washed with a 7% aqueous sodium hydrogen carbonate solution (100 ml) and then with saturated saline, and then dried over anhydrous magnesium sulfate.
The residue was filtered, dried under reduced pressure, and purified by silica gel column chromatography (2% methanol-chloroform) to obtain the title compound (290 mg, 96.9%). This was recrystallized with ethanol and
160 mg of light yellow needle-like crystals were obtained.

¹ H-NMR (DMSO-d ₆ ) δppm: 0.84 (3H,
t, J = 7Hz), 1.10 (6H, d, J = 6Hz),
2.84 (2H, q, J = 7Hz), 2.45−2.80 (5H,
m), 3.04 (2H, s), 3.40−4.00 (4H, br),
5.32 (2H, s), 6.50 (1H, s, _D2O -exchangeable), 7.40-8.10 (4H, m), 8.56 (1H, s) Example 3 7-Methyl-9-[4-(isopropyl) carbamoylmethyl)-1-piperazino]carbonyloxycamptothecin (A) 9-hydroxycamptothecin (100 mg,
0.275 mmol) and ferrous sulfate heptahydrate (100
mg, 0.35 mmol) in concentrated sulfuric acid-water (3 ml-5 ml)
Dissolved in 80% t-butyl hydroperoxide (t-BuOOH) (0.2 ml, 0.18 mol) under ice cooling.
is added dropwise over 0.5 hours. Then, at room temperature,
Stir for 0.5 hour, dilute with ice water (100 ml), collect precipitated crystals, and recrystallize from pyridine-methanol to obtain 9-hydroxy-7-
Methylcamptothecin (49 mg, 47.1%) is obtained.

MP255-258℃ (decomposition) ^1H -NMR (in DMSO- _d6 ) δppm: 0.89 (3H,
t, J=7Hz, _-CH2CH3 ), 1.87(2H,q _,
J=7Hz, _-CH2CH3 ), 2.79(3H,s _, 7-
Me), 5.25 (2H, s, C ⁵ - H ₂ ), 5.42 (2H,
s, ^C17 - _H2 ), 6.49 (1H, s, 20-OH),
7.10−7.19 (1H, m, C ¹¹ −H), 7.32 (1H,
s, ^C14 -H), 7.73-7.76 (2H, m, ^C10 ,
C ¹² -H), 10.69 (1H, s, C ⁹ -OH), MS: m/z 378 [M ⁺ ] (B) Solution of 9-hydroxy-7-methylcamptothecin (100 mg, 0.264 mmol) in pyridine (5 ml) 1-chlorocarbonyl-4-(isopropylcarbamoylmethyl)piperazine (120 mg,
0.5 mmol) and stirred at room temperature for 18 hours.
The reaction mixture was dried under reduced pressure, and the residue was mixed with a mixture of chloroform (300 ml) and 7% aqueous sodium hydrogen carbonate solution (300 ml).The chloroform layer was separated and washed with saturated brine (300 ml). ,
After drying over anhydrous magnesium sulfate, filtration, and drying under reduced pressure, the product was purified by silica gel column chromatography (20% methanol-chloroform) and recrystallized from ethanol to give the title compound as light yellow needle crystals (93 mg, 65 %) was obtained.

Example 4 7-ethyl-9-[4-(1-piperidino)piperidino]carbonyloxycamptothecin (A) 9-methoxycamptothecin (300 mg,
0.79 mmol) was suspended in water (6 ml), and concentrated sulfuric acid (3 ml) was added dropwise to dissolve it. After cooling the solution in an ice bath, propionaldehyde (0.13
ml, 1.6 mmol) and _FeSO4.7H2O ( ₆₀ mg,
0.215 mmol) was added thereto, and 30% hydrogen peroxide solution (0.35 ml, 2.77 mmol) was added dropwise with stirring under cooling in an ice bath. After further stirring at room temperature for 30 minutes, the reaction solution was poured into cold water (1). The resulting insoluble matter was extracted with chloroform, and the chloroform layer was washed with water, dried over anhydrous magnesium sulfate, filtered, and dried under reduced pressure. The residue was recrystallized with ethanol to give 256 mg (79.8%) of 7
Light yellow needle-like crystals of -ethyl-9-methoxycamptothecin were obtained.

MP274-276℃ (decomposition) [EtOH] ¹ H-NMR (in CDCl ₃ ) δppm: 1.02 (3H, t, J
= 8Hz), 1.33 (3H, t, J = 7Hz), 1.92
(2H, q, J=8Hz), 3.06−3.77 (2H, m),
4.03 (3H, s), 5.07 (2H, s), 5.28 (1H,
d, J = 17Hz), 5.67 (1H, d, J = 17Hz),
6.87−7.10 (1H, m), 7.20−7.83 (3H, m) MS m/e: 406 [M ⁺ ] Elemental analysis value (as C ₂₃ H ₁₆ N ₂ O ₅ ) Calculated value C67.97, H5.46 , N6.89 Actual value C67.79, H5.38, N6.82 (B) 7-ethyl-9-methoxycamptothecin (250 mg, 0.62 mmol) in 47% hydrogen bromide water (5 ml)
and heated to 140° C. for 8 hours with stirring. The reaction solution was poured into cold water (1), and the precipitate was collected by suction filtration and recrystallized from ethanol to obtain 100 mg (44%) of pale yellow needle-like crystals of 7-ethyl-9-hydroxycamptothecin.

MP270-272℃ (decomposition) [EtOH] MS m/e: 392 [M ⁺ ] Elemental analysis value (as C ₂₂ H ₂₀ N ₂ O ₅ ) Calculated value C67.33, H5.14, N7.14 Actual value C67 .13, H5.10, N7.33 (C) 7-ethyl-9-hydroxycamptothecin (100 mg, 0.27 mmol) in dry pyridine (6 ml)
1-chlorocarbonyloxy-4-piperidinopiperidine (200 mg, 0.87 mmol) was added thereto, and the mixture was stirred at room temperature for 1 hour. The reaction mixture was dried under reduced pressure, and the residue was subjected to silica gel column chromatography (2% methanol-chloroform).
The residue was purified with ethanol and recrystallized with ethanol to obtain light yellow needle-like crystals (80 mg, 50%) of the title compound.

MP210-212℃ (decomposition) [EtOH] ¹ H-NMR (in CDCl ₃ ) δppm: 1.00 (3H, t, J
=8Hz), 1.17-2.20 (15H, m), 2.20-2.77
(5H, m), 2.77-3.30 (4H, m), 4.20-4.67
(2H, br), 5.20 (2H, s), 5.22 (1H, d,
16Hz), 5.70 (1H, d, J = 16Hz), 7.40−
7.62 (1H, m), 7.62−8.10 (4H, m) Elemental analysis value (as C ₃₃ H ₃₈ N ₄ O ₆・H ₂ O) Calculated value C65.54, H6.67, N9.27 Actual value C65. 34, H6.50, N9.50 Example 5 9-(1-piperazino)carbonyloxy-7-
Propylcamptothecin 9-Hydroxy-7-propylcamptothecin (220 mg, 0.54 mmol) obtained in Example 1(B) was dissolved in dry dioxane (500 mg, 0.54 mmol) containing 0.3 ml of triethylamine.
ml) and phosgene gas (phosgene dimer
0.1 ml, 1.6 mmol) was introduced with stirring at room temperature. The mixture was further stirred at room temperature for 3 hours, the precipitate was removed, and the liquid was dried under reduced pressure. The residue (9-chlorocarbonyloxy-7-propylcamptothecin) was dissolved in 20% methanol containing 0.3 ml of triethylamine.
It was dissolved in chloroform (100 ml), anhydrous piperazine (51 mg, 0.65 mmol) was added to this mixture, and the mixture was stirred at room temperature for 18 hours. Thereafter, in the same manner as in Example 4(C), 28 mg (10%) of the title compound as pale yellow needle crystals were obtained.

Claims (1)

[Claims] 1. General formula (In the formula, R ¹ is a hydrogen atom or a carbon atom of 1 to
(X represents a substituted or unsubstituted piperidine ring or a substituted or unsubstituted piperazine ring) and an ammonium salt thereof.