JP3126798B2 - Optically active indolizine derivative and production method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an optically active ethyl 2-acyloxy-2- [6-cyano-1,1- (ethylenedioxy) -5-oxo-1,2,3,5-tetrahydroindolizine- 7-yl] butanoate and a method for producing the same, and more particularly, to a compound which is an important synthetic intermediate of a camptothecin derivative useful as a synthetic anticancer agent and a method for producing the same.

[0002]

2. Description of the Related Art The following general formula (3)

[0003]

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It is known that the camptothecin derivative represented by the formula is useful as an anticancer agent.

Therefore, the camptothecin derivative (3)
It has been desired to develop a method for easily obtaining an intermediate useful for the production of a compound under mild conditions.

[0006]

Means for Solving the Problems The present inventors have conducted intensive studies in view of the above circumstances, and as a result, have found that enzymes derived from a specific genus and cells of microorganisms belonging to a specific genus, which will be described later, are ethyl 2-acyloxy-2- [ 6-cyano-1,1- (ethylenedioxy) -5-oxo-1,2,3,5-tetrahydroindolizin-7-yl] butanoate decomposes by acting only on the R-form, and only the S-form is decomposed. The inventors have found that they can be left, and have completed the present invention.

That is, the present invention provides an optically active ethyl 2-
Acyloxy-2- [6-cyano-1,1- (ethylenedioxy) -5-oxo-1,2,3,5-tetrahydroindolizin-7-yl] butanoate is provided.

Further, the present invention provides a compound represented by the following general formula (2):

[0009]

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Wherein RCO represents an acyl group, ethyl 2-acyloxy-2- [6-cyano-
1,1- (ethylenedioxy) -5-oxo-1,2,2
3,5-tetrahydroindolizin-7-yl] butanoate is a racemate of Aspergillus and one or two selected from the group consisting of cells, cultures, and fractions of microorganisms belonging to the genus Aspergillus Optically active ethyl 2-acyloxy-2- [6-cyano-1,1- (ethylenedioxy) -5-oxo-1,2,3,5-tetrahydroindolizine; [7-yl] butanoate.

The above optically active ethyl 2-acyloxy-
2- [6-cyano-1,1- (ethylenedioxy) -5
-Oxo-1,2,3,5-tetrahydroindolizin-7-yl] butanoate is preferably represented by the following general formula (1)

[0012]

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(Wherein RCO represents an acyl group) ethyl (S) -2-acyloxy-2- [6-
Cyano-1,1- (ethylenedioxy) -5-oxo-
1,2,3,5-tetrahydroindolizin-7-yl] butanoate.

The acyl group RC of the compound represented by the above general formula (2) and the general formula (1) used in the present invention.
R in O is preferably an alkyl group having 1 to 6 carbon atoms, and particularly preferably a methyl group, an ethyl group, or an n-propyl group.

The racemic compound (2) can be prepared by a known method, for example, as described in J. Am. Chem. Soc. PERKIN TR
ANS. It can be produced by the method described in I27 (1990).

The present invention uses enzymes derived from the genus Aspergillus and cells, cultures and fractions of microorganisms belonging to the genus Aspergillus.

As an enzyme derived from the genus Aspergillus, it is considered that the esterase itself functions as the enzyme from the reaction mechanism of the present invention, but it is difficult to obtain a pure enzyme. In the present invention, an esterase, a protease,
Commercially available enzymes such as cellulase and amidase can be used.

Examples of cultures of microorganisms belonging to the genus Aspergillus include those obtained by culturing the microorganisms in an appropriate medium. As a fraction of the microorganism, a cell or culture is extracted with water or a suitable buffer; when cultured in a liquid medium, a filtrate of the culture, ammonium sulfate or alcohol is added to the extract or filtrate. A precipitate obtained by the addition; a fraction obtained by fractionating the extract or filtrate using gel filtration, ultrafiltration, ion exchange chromatography or the like;
A crushed bacterial cell; and a crushed product obtained by fractionation using the above-described fractionation method can be exemplified.

According to the present invention, first, a racemic compound of the compound (2) is suspended in a mixed solvent of water and an organic solvent such as methanol or ethanol, and then an enzyme derived from the genus Aspergillus and a cell of a microorganism belonging to the genus Aspergillus are cultured. One or two or more selected from the group consisting of a product and a fraction thereof are gently added, and the mixture is stirred and reacted.

The reaction is carried out usually at 5 to 60 ° C., preferably at 30 ° C.
It may be carried out by stirring at 〜50 ° C., pH 4-9, preferably 6-7 for 20-96 hours.

The racemic concentration of the compound (2) used is preferably 0.1 to 1% by weight (hereinafter simply referred to as%),
0.1-0.2% is particularly preferred.

The amount of the above-mentioned enzymes, bacterial cells, cultures, fractions and the like is not particularly limited, but is suitably 1 to 30 times by weight relative to the racemic compound (2).

After the completion of the above reaction, the target compound (1) can be isolated by filtering, reacting under reduced pressure, and using column chromatography.

The compound (1) thus obtained can be prepared by a known method, for example, as described in J. Am. Chem. Soc. PERKIN T
RANS. According to the method described in I27 (1990), camptothecin derivative (3) can be obtained.

[0025]

According to the present invention, the reaction can be carried out under mild conditions, and a side reaction hardly occurs at the time of the reaction, so that a high-purity target compound can be easily obtained. Therefore, the present invention is industrially useful.

[0026]

EXAMPLES The present invention will be described below in more detail with reference to examples, but the present invention is not limited to these examples.

Example 1 Ethyl (S) -2-acetoxy-2- [6-cyano-
1,1- (ethylenedioxy) -5-oxo-1,2,2
Production of 3,5-tetrahydroindolizin-7-yl] butanoate (compound (1)) Ethyl 2-acetoxy-2- [6-cyano-1,1-
(Ethylenedioxy) -5-oxo-1,2,3,5-
300 mg of racemic [tetrahydroindolizin-7-yl] butanoate (compound (2)) is added to 10% methanol (containing 0.1 M phosphate buffer (pH 6.5)) 300
Then, 3.0 g of protease P-3 (from Aspergillus-Sojae, manufactured by Amano Pharmaceutical Co., Ltd.) was added, and the mixture was added at 30 ° C.
For 4 days. After completion of the reaction, 100 ml of chloroform
Was added and stirred for 10 minutes, and the denatured protein was removed by filtration through Celite. The filtrate was separated and the aqueous layer was extracted (chloroform 10
After 0 × 2), the organic layer was collected and dried and distilled. The residue is purified on a silica gel column to give the desired compound (1) 12
5 mg (42% yield) were obtained.

The IR, FT-NMR and MS data are shown below. IRν _max (KBr) cm ^-1 : 2225, 1750, 1640 FT-NMR (δ (ppm) in CDCl ₃ ): 0.85 (3H, t, J = 7 Hz) 1.23 (3H, t, J = 7 Hz) 2.27 ( 3H, s) 2.2-2.7 (4H, m) 4.0-4.5 (8H, m) 6.42 (1H, s) MS (m / z): 390 (M ⁺ )

Next, to measure the optical purity of the compound (1), the compound (1) Chem. Soc. PERK
IN TRANS. (S) -4-Ethyl-6,6 by the method described in I 27 (1990), i.e., nitrile reduction, nitroso transfer and ring closure.
-(Ethylenedioxy) -1,4,7,8-tetrahydro-4-hydroxypyrano [3,4-f] indolizine-3,10- (6H) -dione. The optical purity of the compound was measured using an optical isomer separation column under the following analysis conditions. Analysis conditions Column: ULTORON ES-OVM (manufactured by Shinwa Kako Co., Ltd.) Mobile phase: 2.5% ethanol (containing 20 mM phosphate buffer (pH 6.0)) Flow rate: 1.0 ml / min Wavelength: 300 nm As a result, the optical purity of the target compound (1) is 98%
turned out to be ee.

Example 2 Ethyl (S) -2-acetoxy-2- [6-cyano-
1,1- (ethylenedioxy) -5-oxo-1,2,2
Production of 3,5-tetrahydroindolizin-7-yl] butanoate (compound (1)) Ethyl 2-acetoxy-2- [6-cyano-1,1-
(Ethylenedioxy) -5-oxo-1,2,3,5-
300 mg of racemic [tetrahydroindolizin-7-yl] butanoate (compound (2)) is added to 10% methanol (containing 0.1 M phosphate buffer (pH 6.5)) 300
Then, 6.0 g of a protease (derived from Aspergillus oryzae, manufactured by Sigma) was added, and the mixture was stirred at 30 ° C for 4 days. By performing the same operation as in Example 1, the target compound (1)
120 mg (40% yield) were obtained. The optical purity of the target compound (1) was 96% ee.

Reference Example 2 ml of potato dextrose agar medium was dispensed into a test tube, and the fungal cells (Aspergillus-Candidas IFO-4) were dispensed.
310 Purchased from Fermentation Research Institute) 30
The culture was allowed to stand at 4 ° C. for 4 days. Next, 8 g of the wheat bran in an Erlenmeyer flask was inoculated with the cultured fungal cells, and the temperature was further increased to 30 ° C.
For 4 days. Add 30 ml of distilled water, and add
And then centrifuged (1000-30 minutes) to obtain a mold extract.

Example 3 Ethyl (S) -2-acetoxy-2- [6-cyano-
1,1- (ethylenedioxy) -5-oxo-1,2,2
Production of 3,5-tetrahydroindolizin-7-yl] butanoate (compound (1)) Ethyl 2-acetoxy-2- [6-cyano-1,1-
(Ethylenedioxy) -5-oxo-1,2,3,5-
100 mg of racemic tetrahydroindolizin-7-yl] butanoate (compound (2)) in 90 ml of 10% methanol (containing 0.1 M phosphate buffer (pH 6.5))
And 10 ml of the above extract was added, followed by stirring at 30 ° C. for 4 days. By performing the same operation as in Example 1, the target compound (1)
38 mg (38% yield) were obtained. The optical purity of the target compound (1) was 90% ee.

Continued on the front page (72) Inventor Akihiro Imura 1-16-13 Kita-Kasai, Edogawa-ku, Tokyo Dai-ichi Pharmaceutical Co., Ltd. Tokyo Research and Development Center (58) Field surveyed (Int.Cl. ⁷ , DB name) C07D 491/20 C12P 41/00 BIOSIS (DIALOG) CA (STN) REGISTRY (STN)

Claims (3)

(57) [Claims] 1. Ethyl (S) -2-acyloxy-2
-[6-cyano-1,1- (ethylenedioxy) -5-
Oxo-1,2,3,5-tetrahydroindolizine-
7-yl] butanoate. 2. The following general formula (2): (Wherein, RCO represents an acyl group) ethyl 2-acyloxy-2- [6-cyano-1,1- (ethylenedioxy) -5-oxo-1,2,3,5-tetrahydroindo Reaction of a racemic form of [lysine-7-yl] butanoate with one or more selected from the group consisting of an enzyme derived from the genus Aspergillus, a cell of a microorganism belonging to the genus Aspergillus, a culture, and a fraction thereof. The following general formula (1) characterized by the following: (Wherein, RCO represents an acyl group) ethyl (S) -2-acyloxy-2- [6-cyano-1,
1- (ethylenedioxy) -5-oxo-1,2,3
5-tetrahydroindolizin-7-yl] butanoate. 3. The following general formula (2): (Wherein, RCO represents an acyl group) ethyl 2-acyloxy-2- [6-cyano-1,1- (ethylenedioxy) -5-oxo-1,2,3,5-tetrahydroindo (Lysin-7-yl) butanoate is reacted with one or more species selected from the group consisting of enzymes derived from the genus Aspergillus, microorganisms belonging to the genus Aspergillus, cultures, and fractions thereof. Only the R form is decomposed to leave the S form, and the decomposed product of the R form and S
The following general formula (1) characterized in that the body is separated: (Wherein, RCO represents an acyl group) ethyl (S) -2-acyloxy-2- [6-cyano-1,
1- (ethylenedioxy) -5-oxo-1,2,3
5-tetrahydroindolizin-7-yl] butanoate.