KR810001323B1 - Process for preparing lasalocid derivatives - Google Patents

Abstract

Title compds. (I; R1 = H, aryl, substituted aryl, aralkyl lower alkyl, alkenyl, carboalkoxy), useful as antihypertensives, were prepd. by reacting compds. II (R2,R3 is lower alkyl or forms 5- or 6-membered heterocycle with N) with R1SH in the presence of weak base. Thus, lasalocid ethanolate, paraformaldehyde and diethylamine were dissolved in toluene and refluxed for 90 min to give 1-(diethylaminomethyl)-1-decarboxylasalocid, this mannich base was dissolved with thiophenol and triethylamine in EtOH and refluxed for 18 hr, distilled, washed, and dried to give 1-(phenylthiomethyl)-1-decarboxy lasalocid.

Description

Preparation of Lasaloside Derivatives

The present invention relates to a method for preparing the compound of formula (I), which is useful as a therapeutic agent for hypertension.

Wherein R ¹ is aryl, substituted aryl, heteroaryl, aralkyl, cycloalkyl, lower alkyl, lower alkanyl, carboalkoxy lower alkyl, aminoalkyl, lower alkylaminoalkyl, di (lower alkyl) aminoalkyl, hydroxy Oxyalkyl, alkoxyalkyl, thioalkoxyalkyl, carboxy loweralkyl or hydrogen.

The term "alkyl" as used herein is a straight or branched chain hydrocarbon group having 1 to 16 carbon atoms, alone or in admixture with other groups. Preferred alkyl groups are lower alkyl groups. The term "lower" refers to a group having 1 to 7 carbon atoms. Representative examples of lower alkyl groups are methyl, ethyl, isopropyl and tertiary butyl.

The term “aryl” refers to an unsubstituted mono-carboxyaromatic moiety such as phenyl.

Examples of “substituted aryl” include alkyl, carboxy, halo, alkoxy or phenyl substituted by nit such as tolyl.

The term “halogen” or “halogen” is used to include all four forms thereof, chlorine, bromine, fluorine and iodine.

The "cycloalkyl" site preferably contains 4 to 7 carbon atoms, such as cyclohexyl.

The term “heteroaryl” refers to an unsubstituted mono-heterocyclic aromatic moiety such as pyridyl or furyl.

The term “aralkyl” refers to straight or branched chain alkyl substituted with a mono-carbocyclic site such as benzyl.

The term "lower alkanyl" refers to a straight or branched chain hydrocarbon group containing an olefinic double bond having 2 to 6 carbon atoms.

Preferred groups of the compounds of formula (I) are those in which R ¹ is aryl, substituted aryl, aralkyl, cycloalkyl, lower alkyl, carboxy lower alkyl or hydrogen. Particularly preferred are those compounds of formula (I) wherein R ¹ is phenyl, chlorophenyl, cyclohexyl, benzyl or carboxymethyl. Best of all is a compound of formula (I) wherein R ¹ is phenyl, i.e., a compound of 1- (phenylthio methyl) -1-decarboxylasaloside.

The process for preparing the compound of formula (I) according to the present invention is characterized in that the following compound of formula (II) is reacted with a compound wherein R ¹ SH is present in the presence of a weak base (wherein R ¹ is as described above).

In the above formula, R ² and R ³ are each lower alkyl or form a 5- or 6-membered heterocyclic ring containing one more hetero atom together with the nitrogen atom.

의 공역염기를 생성하기에 충분한 것이며 라살로시드 분자의 리트로알돌의 분해를 야기하지는 않는다. 적절한 염기는 탄산 및 중탄산나트륨 또는 탄산칼륨 트리알킬아민 또는 피리딘과 같은 알칼리금속을 포함하여 적절한 용매는 메탄올 또는 에탄올과 같은 알코올, 고비점 에테르, 디옥산 또는 테트라하이드로푸란 및 에틸아세테이트 등이다. 반응온도는 실온 내지 환류온도이며 그중 선택된 용매의 환류온도가 바람직하다. 바람직한 반응물은 티오페놀, P-클로로티오페놀, 사이클로헥실메르캅탄, 벤질메르캅탄 및 메르캅토 아세트산 등으로서 각각 R¹이 페닐, P-클로로페닐, 사이클로헥실, 벤질 및 카복시메틸인 구조식(Ⅰ)화합물을 수득한다.Suitable weak bases in this reaction are orthoquinone meted and selected mercaptans, ie R^OneS

It is sufficient to produce conjugated bases of and does not cause degradation of the ritroaldol of the lasaloside molecule. Suitable bases include carbonates and alkali metals such as sodium bicarbonate or potassium carbonate trialkylamine or pyridine. Suitable solvents are alcohols such as methanol or ethanol, high boiling ethers, dioxane or tetrahydrofuran and ethyl acetate and the like. The reaction temperature is from room temperature to reflux temperature, of which reflux temperature of the selected solvent is preferred. Preferred reactants are thiophenol, P-chlorothiophenol, cyclohexyl mercaptan, benzyl mercaptan, mercapto acetic acid and the like, respectively.^OneThis yields the compound of formula (I) which is phenyl, P-chlorophenyl, cyclohexyl, benzyl and carboxymethyl.

The starting material of formula (II) is a Mannich reaction of lasaloside of formula (III), in particular dialkylamines or cyclic amines, for example paraforms of morpholine, piperidine, pyrrolidine and the like with aqueous formaldehyde. Obtained by reaction with a mixture of aldehydes.

Suitable solvents are C ₁ -C ₄ alcohols, toluene, benzene, chlorinated hydrocarbons and ethers such as dioxane or tetrahydrofuran. The reaction temperature is in the range between 60 and the reflux temperature of the solvent, and the reflux temperature is preferably used.

Antibiotic Lasaloside, also known as X-537A, is an antibiotic produced by Streptomyces strain isolated from soil feed collected from Hyde Park, Massachusetts. Lyophilized culture tubes, designated Lab Designation X-537, are stored in Peoria, Illinois, the United States Department of Agriculture, Agricultural Research Service, and Northern Utilization Research and Development Division. Veggies identified as NRRL 3382 by the Agricultural Research Service may be made available to the public via NRRL. Replaceable cultures, ie cultures with identical parent strains and morphological characteristics, which are very similar to the original stored strain NRRL 3382, are stored in NRRL and are named NRRL 3382R. This culture can also be used by the public with NRRL 3382, the original stored culture.

Lasaloside (antibiotic X-537A) is prepared by growing a Streptomyces strain by aerobic deep cultivation using a broth adjusted to a neutral pH of 6.5 to 7.5. The medium used contains yeast, products derived from yeast, corn flour, soy flour and other substances, most preferably nitrogen sources such as soy flour and carbohydrate sources such as sucrose and molasses most preferably brown sucrose. Fermentation is carried out at slightly elevated temperatures, such as 25-25 ° C. (preferably at 28 ° C.). After culturing for 4 to 6 days, the fermented broth is filtered and extracted to recover antibiotics.

Structural formula (I) compounds exhibit antihypertensive activity.

As a control, the antihypertensive activity is tested using the standard 1- (phenylthio-methyl) -1-decarboxylasaloside (formula (I) compound wherein R ¹ is phenyl). The test is performed orally once daily for 5 days in DOCA-Na rats and stops after 5 days. Blood pressure is measured daily until the blood pressure is reduced to the pre-medication blood pressure during the above 5 days and after the administration is stopped. The single dose is 10 mg / kg / day. The results are shown in the following table.

^a DOCA-Na hypertensive male rat is orally administered with a carrier (5% gum arabic) or a drug with 1- (phenylthiomethyl) -1-decarboxylaserose in gum arabic for 5 days. . Contractile blood pressure and heart rate are measured before (AM) and after 6 hours (PM) addition of carrier or drug. N represents the number of test animals used.

1-[(carboxymethyl) thiomethyl] -1-decarboxylazaloside, 1- (P-chlorophenylthiomethyl) -1-decarboxylacylate, 1- (benzylthiomethyl) -1-decarboxy Lasalosides and 1- (cyclohexylthiomethyl) -1-decarboxyrasaloside are also tested for antihypertensive activity.

The test is performed once daily orally in DOCA-Na rats for 5 days and stops after 5 days. Blood pressure is measured daily for 5 days and after stopping the administration until the blood pressure is reduced to the pre-dose blood pressure. The daily dose is 10 mg / kg / day. It is clear from these results that the compound exhibits antihypertensive activity when there is a difference in the initiation and persistence of antihypertensive activity and efficacy, but when comparing blood pressure between days 1 and 5. The result is as follows.

^a DOCA-Na hypertensive male rat is orally administered once with each compound for 5 consecutive days. Contractile blood pressure and heart rate are measured before and after the drug (AM) and 6 hours after administration. N represents the number of animals used.

Representative tablets and capsules shown below are used to administer the required amount of the active ingredient. It is to be understood that the preferred compound of the present invention, 1- (phenylthiomethyl) -1-decarboxylasaloside, is used in the following examples but all compounds described herein as effective compounds may be used instead. .

[Way]

1. Mix ingredients 1, 3 and 5 in a suitable mixer.

2. Dissolve components 2 and 5 in distilled water and / or alcohol, granulate to an appropriate hardness, and powder.

3. Dry in a suitable oven.

4. After powdering, mix with talc and magnesium stearate for 3 minutes.

5. Fill the capsules.

[Way]

1. Mix ingredients 1 to 4 in a suitable mixer.

2. Granulate a sufficient amount of distilled water to a suitable hardness and then powder it.

3. Dry in oven.

4. After powdering, mix with magnesium stearate for 3 minutes.

5. Tablet at the proper pressure.

To reduce blood kinetics to normal using antihypertensive agents, the active ingredient is formulated in a dosage form suitable for oral administration using conventional acyclic pharmaceutical suppository materials. Other dosage forms such as parenteral administration are also possible. Oral formulations include tablets, capsules, dragees, suspensions, solutions and other formulations. Inert suppositories used to formulate active ingredients in oral formulations are evident to experts in this area. Inorganic or organic suppositories contain gelatin, albumin, lactose, starch, magnesium stearate, preservatives (stabilizers), dissolving agents, emulsifiers, salts for changing the osmotic pressure, buffers and the like, if necessary. It may also be incorporated into the formulation.

Subacute oral administration of the active ingredient for the treatment of hypertension, ie up to 5 days in warm-blooded animals such as DOCA-Na hypertensive mice, after which the dose is stopped, the dosage is from 5 mg / kg / day to 100 mg / kg / It has already been found to be most effective when in the range of days, more preferably 5 mg / kg / day to 10 mg / kg / day. Chronic oral administration of the active ingredient, i.e. when administered over 5 days, is most effective when using a lower dose, i.e., less than 0.1 mg / kg / day, such as 0.01 mg / kg / day to 5 mg / kg / day. Such dosage regimens are also used to treat other cardiovascular problems such as eye catching, lameness, and decreased blood flow to the brain. Treatment of these problems is effectively affected by the fact that arterial blood flow increases with increasing pulse velocity and therefore secondly the blood flow is more compliant to be controlled by pressure intensity rather than kinetic energy.

Most preferred among the above dosage regimens is a chronic low dose of the active ingredient, i.e., 0.1 mg / kg / day to 5 mg / kg / day or less. In particular, the amount administered to an individual will vary within the range of dosages based on the toxicity of the particular polyether. The desired antihypertensive effect is the action of the efficacy of the particular compound and the weight and physical conditions of the individual patient. Therefore, the effective dosage of the active compound is determined by the judgment of the physician on behalf of the patient.

Example 1

Streptomyces strain NRRL 3382R is grown in aerobic deep cultures in shake flasks. The pH of the broth is adjusted to 6.5 to 7.5 by adding KOH solution and then sterilized. The tank is fermented using 5 to 10% of the inoculum grown by deep culture for 3 days in the air-blown bottle. The medium contains 2% soy flour, 2% brown sucrose, 0.5% corn steep liquor and 0.1% K ₂ HP ₄ . Fermentation is carried out under positive atmospheric pressure at a flow of 5 to 10 cubic feet of air at 28 ° C. and 1 minute per feed of 40 to 80 gallons. 4-6 days after fermentation, the juices are collected, filtered and extracted to recover antibiotics. Extraction is performed as follows.

204 L of the juice is filtered off and the wet filter cake is suspended in 100 L of butyl acetate and then the mixture is stirred overnight at room temperature. The mixture is filtered and the aqueous layer is separated and discarded. The butyl acetate solution (30 million Bacillus units) is concentrated in vacuo to 3 L, washed with 10% sodium carbonate solution and dehydrated with anhydrous sodium sulfate.

Further concentration to 300 ml and dilution with 350 ml of petroleum ether (boiling point 50-60 ° C.) separates 41 g of solids (25 million visilus units). This solid material is extracted with 4 L of petroleum ether (boiling point 50-60 ° C.) for 40 hours in a Soxhlet apparatus. The extract was dried in vacuo and the crystalline residue was suspended in petroleum ether and filtered to give 3-methyl-6- [7-ethyl-4-hydroxy-3,5-dimethyl-6-oxo-7- [5-ethyl In the form of salts and free acids of -3-methyl-5- (5-ethyl-5-hydroxy-6-methyl-2-tetrahydropyranyl) -2-tetrahydrofuryl] heptyl] salicylic acid (lasaloside) 24.49 g of a mixture are obtained. 5.73 g of antibiotic are further obtained from the mother liquor.

After recrystallization in ether-petroleum ether, the material containing sodium is dissolved in ether, washed with dilute sulfuric acid and converted to free acid. The ether is removed to give an oily residue which is crystallized in ethanol to give pure lasaloside ethanolate. Recrystallization several times in ethanol does not change the melting point is maintained at a temperature of 100 to 109 ℃.

Example 2

1- (diethylaminomethyl) -1-decarboxylasaloside

A solution of a mixture of lasalosidethanolate (5.0 g), paraformaldehyde (2.5 g) and diethylamine (2.5 g) in toluene (200 ml) is stirred and heated at reflux for 90 minutes.

During reflux, the water is collected in a trap and the solution is diluted with ether and passed through a separatory funnel. Wash with water and wash again with very dilute (about 0.05N) hydrochloric acid. After drying and filtration of the organic layer, the solvent is removed under reduced pressure to give a pale yellow (sometimes colorless) resin. The resulting impure Mannich base contains the residual components of toluene but is used directly in the next step.

Example 3

1- (phenylthiomethyl) -1-decarboxylasaloside

The Mannich base (9.7 g), thiophenol (4.5 ml) and triethylamine (4 ml) of Example 2 were dissolved in ethanol (125 ml) and then heated under reflux for 18 hours. The solvent is evaporated under reduced pressure and the residue is treated in CH ₂ Cl ₂ , washed with water and dilute aqueous sodium carbonate and dried and the solvent is evaporated to give an impure product. The product is purified by chromatography on a silica gel (200 g) column. The thiophenol is eluted with hexane / ethyl acetate (8: 1) and the product is eluted with hexane / ethyl acetate (6: 1). Finally, the solvent is evaporated using a vacuum pump to give a colorless foam.

Example 4

1- (P-chlorophenylthiomethyl) -1-decarboxylasaloside

Dissolve 1- (diethylaminomethyl) -1-decarboxylasaloxide (1.4 g) P-chlorothiophenol (2 g), and triethylamine (2 ml) in ethanol (50 ml), and reflux for 18 hours. do. Since the reaction is not complete (TLC), P-chlorothiophenol (2 g) and triethylamine (2 ml) are added further and reflux is continued for 24 hours. After cooling the solvent and amine are evaporated under reduced pressure and the residue is treated in methylene chloride. The solution is washed with an aqueous solution of sodium carbonate followed by dehydration and evaporation with sodium sulfate.

The residue of the mixture consisting mainly of P-chlorothiophenol and the desired thioether is chromatographed on silica gel using benzene / ethyl acetate (2: 1) as the eluent. The fractions containing the desired product are mixed and then evaporated to yield a colorless solid foam having a melting point of 42 to 46 ° C.

Example 5

1- (cyclohexylthiomethyl) -1-decarboxylasaloside

Dissolve 1- (diethylaminomethyl) -1-decarboxylasaloside (1.4 g), cyclohexyl mercaptan (2 ml) and triethylamine (2 ml) in ethanol (50 ml) and heat to reflux. A larger amount of cyclohexyl mercaptan and triethylamine were added to carry out the same procedure as described in Example 4, and then purified by column chromatography on silica gel to give a colorless solid foam product.

Example 6

1- (benzylthiomethyl) -1-decarboxylasaloside

Dissolve 1- (diethylaminomethyl) -1-decarboxylasaloside (4.5 g), benzyl mercaptan (5 ml) and triethylamine (5 ml) in ethanol (100 ml) and heat to reflux overnight. After cooling and evaporating the solvent under reduced pressure, the residue was chromatographed on silica gel using hexane / ethyl acetate (5: 1) as the eluent. Fractions containing the desired product are collected and evaporated to yield the final product. The product is contaminated with a small amount of benzyl mercaptan and further purified by PLC using hexane / ethyl acetate (4: 1) as a developing solvent on six 20 × 20 cm silica gel plates. Pure product is obtained as a colorless solid foam.

Example 7

1-[(carboxymethyl) thiomethyl] -1-decarboxylasaloside

Mannich base, mercapto-acetic acid (3 ml) and triethylamine (3 ml) of Example 2 (3 g) were dissolved in 100 ml of ethanol and heated at reflux for 36 hours. After ethanol was removed by evaporation under reduced pressure, the residue was dissolved in CH ₂ Cl ₂ and the solution was washed again with dilute aqueous sodium carbonate, water, 0.5N HC1 and finally water. After drying and evaporation, the crude product is purified by chromatography on silica gel using a solution of 4% MeOH in CHCl ₃ as eluent. This product absorbs sodium ions from the inorganics, so the eluate containing the product is washed with very dilute HCl before evaporation to give a colorless foamy final product.

Example 8

1-mercaptomethyl-1-decarboxylasaloside

A solution of 1- (diethylaminomethyl) -1-decarboxylasaloside (1.85 g) and triethylamine (2 ml) in ethanol (50 ml) was bubbled by slowly passing hydrogen sulfide gas through the solution for 32 hours. Heat at reflux. The residue obtained by evaporating the solvent under reduced pressure was subjected to PLC (20 x 20 cm, silica gel) to obtain a colorless solid foamy target product.

Example 9

1- (methylthiomethyl) -1-mecaboxyrasaloside

A solution of 1- (diethylaminomethyl) -1-decarboxylasaloxide (1 g) and triethylamine (2 ml) in ethanol (50 ml) was passed through gaseous methyl mercaptan for 8 hours at reflux temperature. Heat. Evaporation and purification with PLC yield 300 g of the desired product as a colorless solid foam.

Example 10

1- (2-furylmethylthiomethyl) -1-decarboxylasaloside

A solution of 1- (diethylaminomethyl) -1-decarboxylasaloxide (1.4 g) furfuryl mercaptan (2 ml) and triethylamine (2 ml) in ethanol (50 ml) was added after 18 hours. Mercaptan (2 ml each) was added and heated at reflux for 42 hours. After evaporation it is purified by PLC to give the desired product as a colorless solid foam.

Example 11

According to the above process using a commercially available thiol, R ¹ is allyl, 2-aminophenyl, 4-aminophenyl, 4-bromo-3-methylphenyl, 4-bromophenyl, 1-butyl, 2 -Butyl, tertiary butyl, isobutyl, carboethoxymethyl, carbomethoxymethyl, 2-carboxyethyl, 0-carboxyphenyl, 4-chlorobenzyl, 2-n-decylaminoethyl, 2,5-dichlorophenyl, 3,4-dichlorophenyl, 2-diethylaminoethyl, 2-diisopropylaminoethyl, 1-dodecyl, ethyl, 4-fluorophenyl, n-heptyl, n-hexadecyl, 2-hydroxyethyl, 2-ethoxyethyl, 2-ethylthioethyl, 1-methyl-2-imidazolyl, 2,3-dihydroxypropyl, 2-pyridyl, 4-pyridyl, 3-hydroxy-2-pyridyl , 2-thiazolyl, 2-methoxyphenyl, 3-methoxyphenyl, 4-methoxyphenyl, 2-methyl-2-butyl, 3-methyl-1-butyl, 4-nitrophenyl, 1-nonyl, 1 -Octyl, pentachlorophenyl, pentafluorophenyl, 1-pentyl, 3-phenyl-1-propyl, 1-propyl, 2-propyl, 2- Compounds that are nolin, 2,3,5,6-tetrafluorophenyl, P-tolyl, 2,4,5-trichlorophenyl, 7-trifluoromethyl-4-quinoline, or triphenylmethyl can also be prepared. have.

The present invention is further described as follows.

1. A process for preparing the following compound of formula (I), wherein the compound of formula (II) is reacted with a compound of the formula R ¹ SH (R ¹ is as described below) in the presence of a weak base.

Wherein R ¹ is aryl, substituted aryl, heteroaryl, aralkyl, cycloalkyl, lower alkyl, lower alkenyl, carboalkoxy lower alkyl, amino alkyl, lower alkylaminoalkyl, di (lower alkyl) aminoalkyl, hydr Oxyalkyl, alkoxyalkyl, thioalkoxyalkyl, carboxyloweralkyl or hydrogen and R ² and R ³ are each lower alkyl or together with a nitrogen atom to form a 5- or 6-membered heterocyclic ring which may further contain one heteroatom; do.

2. The process according to 1 above, wherein a compound of formula (I) is prepared wherein R ¹ is aryl, substituted aryl, aralkyl, cycloalkyl, lower alkyl, carboxy lower alkyl or hydrogen.

3. The process according to 1 or 2 above, wherein a compound wherein R ¹ is aryl is prepared.

4. The process according to 3 above, wherein a compound is prepared wherein R ¹ is phenyl.

5. The process according to 1 or 2 above, wherein a compound is prepared wherein R ¹ is chlorophenyl, cyclohexyl, benzyl or carboxy methyl.

Claims (1)

A process for preparing the following compound of formula (I), wherein the compound of formula (II) is reacted with a compound of formula R ¹ SH in the presence of a weak base.

R ¹ in the formula is aryl, substituted aryl, heteroaryl, aralkyl, cycloalkyl, lower alkyl, lower alkenyl, carboalkoxy lower alkyl, aminoalkyl, lower alkyl aminoalkyl, di (lower alkyl) aminoalkyl, hydroxy Oxyalkyl, alkoxyalkyl, thioalkoxyalkyl, carboxyloweralkyl or hydrogen and R ² and R ³ are each lower alkyl or together with a nitrogen atom to form a 5- or 6-membered heterocyclic ring which may further contain one heteroatom; do.