JPH0339077B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a phosphorus-containing oligopeptide having an angiotensin-converting enzyme inhibitory effect and an antihypertensive effect, and a pharmacologically acceptable salt thereof. More specifically, the present invention relates to the general formula []: [In the formula, R ₁ represents hydrogen, lower alkanoyl or lower alkoxycarbonyl, R ₂ represents lower alkyl or benzyl, R ₃ represents hydrogen or benzyl, and R ₄ represents hydrogen or lower alkyl. however,
When R ₄ is hydrogen, methyl, or ethyl, R ₁ is not acetyl, R ₂ is benzyl, and R ₃ is not hydrogen. ] (hereinafter referred to as phosphorus-containing oligopeptide)
It is called a compound. The same applies to compounds of other formula numbers) and pharmaceutically acceptable salts thereof. Conventionally, as a peptide-based compound with angiotensin-converting enzyme inhibitory action, the general formula (In the formula, X _a is CH ₂ or S, and R _a is hydrogen or benzyl). Furthermore, there are a series of applications filed by the present applicant regarding novel phosphorus-containing oligopeptides that have strong angiotensin-converting enzyme inhibitory effects and antihypertensive effects [Japanese Patent Application No. 56-40651 (Japanese Patent Application No. 57-156498); 128740, patent application 184198
-85896), patent application No. 56-184199 (Japanese Patent Application No. 58-85897). Based on these findings, the present inventors further investigated the synthesis of novel phosphorus-containing oligopeptides and found that the compound [] exhibits excellent angiotensin-converting enzyme inhibitory activity and antihypertensive activity. I was able to complete it. Next, the present invention will be explained in more detail. In the definition of R ₁ in the general formula [], lower alkanoyl refers to a straight chain or branched alkyl moiety having 1 to 6 carbon atoms, and preferred examples include acetyl and propionyl. It means lower alkoxycarbonyl or straight chain or branched lower alkoxycarbonyl having 2 to 7 carbon atoms. Suitable examples include ethoxycarbonyl, propoxycarbonyl, and t-butoxycarbonyl. R ₂ is a part corresponding to the side chain of a general amino acid. In the definition of R ₂ , lower alkyl has 1 carbon number
~6 straight or branched chain. Preferably methyl, i-propyl, 1-methylpropyl, 2
- Examples include methylpropyl. In the definition of _R4 , lower alkyl means a straight chain or branched alkyl having 1 to 6 carbon atoms. Suitable examples include methyl, ethyl, and propyl. When the compound [] is an acidic compound, a base addition salt can be formed, and when it is a basic compound, an acid addition salt can be formed. Such salts include ammonium salts, alkali metal salts such as lithium, sodium and potassium salts, alkaline earth metal salts such as calcium and magnesium salts, salts with organic bases such as triethylamine, morpholine, piperidine and dicyclohexylamine. Also includes salts with amino acids such as arginine and lysine. Furthermore, salts with inorganic and organic acids, such as hydrochlorides, hydrobromides, sulfates, nitrates, formates,
Also salts such as acetate, benzoate, maleate, fumarate, succinate, tartrate, citrate, oxalate, methanesulfonate, toluenesulfonate, aspartate, glutamate, etc. can be made. Although non-toxic pharmaceutically acceptable salts are preferred, other salts are also useful in isolating and purifying the product. These salts can be made by conventional methods. For example, compound [] and compound [] may be reacted with one or more equivalents of a suitable base or acid in a solvent such as water or an alcohol, and the solvent is removed by vacuum or freeze-drying, or a suitable ion It can be formed by exchanging the cation of the salt of the compound [ ] with another cation on an exchange resin. In the general formula [], CH ₃ CH ₂ CH (CH ₃ )−,
R ₂ (if not hydrogen) and

The carbon atom to which [Formula] is bonded is an asymmetric carbon. According to the present invention, racemic, enantiomeric, and diastereomeric products can be obtained by selecting the starting materials and intermediates used. If a mixture of diastereomers is obtained, it can be separated by conventional chromatography or fractional crystallization methods. In the present invention, the purpose can be achieved regardless of whether the configuration of the asymmetric carbon is R or S, but it is more preferable to use CH ₃ CH ₂ CH in the general formula [].
The carbon to which (CH ₃ )- and R ₂ are bonded has an S-configuration;

[Process-1]

The invention regarding the compound [] has been filed by the present applicant [Patent Application 1983-
184199 (Japanese Patent Application Laid-open No. 58-85897)], these compounds can also be synthesized by combining known methods [Reference: MJStringer et al.
al, Chem.Biol.Interactiors, 9 , 411 (1974),
ZHKudzin and A. Kotynski, Synthesis,
1028 (1980)]. The other raw material, compound [], is a protected amino acid generally used in the field of peptide synthesis chemistry. Condensation of compounds [] and [] can be carried out using a condensing agent generally used in peptide synthesis. For example, N,N'-dicyclohexylcarbodiimide (hereinafter abbreviated as DCC) and
Combinations such as DCC and 1-hydroxybenzotriazole or N-hydroxysuccinimide are also used. Furthermore, a mixed acid anhydride method using ethyl chlorocarbonate, isobutyl chlorocarbonate, etc., and an active esterification method via p-nitrophenyl ester, etc. can also be applied. The reaction solvent is a solvent normally used for peptide synthesis,
For example, tetrahydrofuran, dioxane, chloroform, dichloromethane, ethyl acetate,
N,N-dimethylformamide or a mixed solvent thereof is used. Also, the reaction is usually −
It is carried out within the range of 30° to +30°C. After condensing compound [] and [], the amino protecting group Y can be removed by a method commonly used in peptide synthesis to lead to compound []. For example, when Y is a t-butoxycarbonyl group, the compound [ ] can be obtained by treatment with an acid such as hydrogen chloride, and when Y is a benzyloxycarbonyl group, the compound [ ] can be obtained by catalytic reduction. In addition, when the compound [] is an optically inactive form and the compound [] is an optically active form, it is possible to separate the compound [] as diastereomers. Compound [] can also be isolated as an acid addition salt such as hydrochloride or hydrobromide, and in that case, it can be used as it is as a raw material for [Step-2]. [Step-2] Compound ['] can be obtained basically by the same reaction and treatment as in [Step-1].
That is, the compound [] obtained by the method of [Step-1] and the compound [] were reacted under the same conditions using the condensing agent commonly used in the field of peptide synthetic chemistry shown in [Step-1]. The desired product can be obtained by this treatment. In addition, to obtain a compound in which R ₁ is hydrogen in the general formula ['], R ₁ is lower alkoxycarbonyl (for example, t-butoxycarnyl).
The compound ['] of the present invention shown in [Step-1] may be subjected to a deprotection treatment (such as acid treatment) commonly used in the field of peptide synthetic chemistry. In addition, the compound in which R ₁ is lower alkanoyl in the general formula ['] can be used in the above [Step-
1], a compound in which R ₁ is hydrogen in the general formula ['] obtained by [Step-2] and the formula
R ₁ −X (X is halogen,

[Formula] or

[Formula]) is reacted in the presence of a base (for example, triethylamine, pyridine, N-methylmorpholine, etc.), or a compound represented by the general formula ['] in which R ₁ is hydrogen is reacted with R ₁ -
It can also be synthesized by reacting with OH in the presence of a condensing agent (DCC, alkyl chlorocarbonate, etc.). [B] Synthesis of a compound in which R ₃ and R ₄ are both hydrogen in the general formula [] A compound in which R ₃ and R ₄ are hydrogen in the general formula [] is a compound in which R ₃ is benzyl in the general formula [] , R ₄ is lower alkyl such as methyl or ethyl, by dissolving the compound in an acetic acid solution containing hydrogen bromide and stirring at room temperature for several hours to one day. The present invention will be explained in more detail with reference to Examples below. Example 1 N-(N-t-butoxycarbonyl-L-isoleucyl-L-phenylalanyl-(R)-(-)
-1-amino-2-(4-benzyloxyphenyl)ethylphosphonic acid diethyl ester (1) N-L-phenylalanyl-(R)-(-)-1
-amino-2-(4-benzyloxyphenyl)
Ethylphosphonic acid diethyl ester/hydrochloride (±)-1-amino-2-(4-benzyloxyphenyl)ethylphosphonic acid diethyl ester (see Reference Example 1) 7.26 g (20 mmol), N-t-
Butoxycarbonyl-L-phenylalanine
After dissolving 5.57 g (21 mmol) and 2.84 g (21 mmol) of 1-hydroxybenzotriazole in 30 ml of tetrahydrofuran (hereinafter abbreviated as THF),
Dry ice while stirring the solution - approx.
Cooled to 10°C. Add N,N'-dicyclohexylcarbodiimide (hereinafter abbreviated as DCC) to this solution.
A solution of 4.33 g (21 mmol) in THF (5 ml) was added dropwise. After raising the reaction solution to 0° C. over about 2 hours, it was stirred at room temperature overnight. Precipitated N,
N'-dicyclohexylurea was filtered off, and 100 ml of ethyl acetate was added to the filtrate. The resulting homogeneous solution was washed with a 5% aqueous sodium bicarbonate solution, a 5% aqueous citric acid solution, and then a saturated saline solution (3x each).
30ml). The organic layer was dried with anhydrous sodium sulfate,
The solvent was removed under reduced pressure to obtain 11.3 g of pale yellow powder. Add 30ml of ethyl acetate to this powder to make a homogeneous solution, then add 150ml of 2.6N hydrogen chloride ethyl acetate solution.
was added and stirred at room temperature for 1 hour. The solvent and excess hydrogen chloride were removed under reduced pressure to give a pale yellow gum. This compound is silica gel TLC
Top (chloroform-methanol 9:1), Rf=
I gave two spots to 0.45 and 0.24. It was subjected to silica gel column chromatography and developed with a mixed solvent of chloroform-methanol 96:4, the fraction containing the compound with Rf = 0.45 was collected, the solvent was removed under reduced pressure, and 4.01 g (70
%) was obtained. The physicochemical data of this compound are as follows. Γ [α] ¹³ _D = -36.2° (C = 1.01, methanol) Γ ¹ H-NMR (CDCl ₃ ): δ7.45-6.7 (m,
14H), 4.95 (s, 2H), 4.6 (m, 1H), 4.02
(m, 4H), 3.4-2.6 (m, 4H), 1.25 (t,
3H, J = 7Hz), 1.20 (t, 3H, J = 7Hz) ΓMS (20eV): m/z 510 (M ⁺ -HCl) From the above data, the substance was identified as the title compound. (2) N-(N-t-butoxycarbonyl-L-isoleucyl-L-phenylalanyl-(R)-
(-)-1-Amino-2-(4-benzyloxyphenyl)ethylphosphonic acid diethyl ester N-t-butoxycarbonyl-L-isoleucine 673 mg (2.91 mmol), N-L-phenylalanyl-(R)-( -)-1-amino-2-(4-
Benzyloxyphenyl)ethylphosphonic acid diethyl ester hydrochloride 1.59g (2.911mmol),
1-Hydroxybenzotriazole 413mg
After dissolving (3.06 mmol) in 30 ml of THF, the solution was heated at approximately -10℃ in a dry ice/ice bath while stirring.
It was cooled to Add N-methylmorpholine to this solution.
0.336ml (3.06mmol) then DCC631mg
(3.06 mmol) in THF (10 ml) was added dropwise.
After raising the reaction solution to 0° C. over about 2 hours, it was stirred at room temperature overnight. Precipitated N, N'-
Dicyclohexylurea was filtered off, and 100 ml of ethyl acetate was added to the filtrate. The resulting homogeneous solution was washed with a 5% aqueous sodium bicarbonate solution, a 5% aqueous citric acid solution, and then a saturated saline solution (3 x 30 ml each).
The organic layer was dried over anhydrous sodium sulfate and the solvent was removed under reduced pressure to obtain a pale yellow solid. This was purified by silica gel chromatography (ethyl acetate), and the solvent was removed under reduced pressure to form a white powder.
2.0g (95%) was obtained. The analytical values and physicochemical data of this compound are as follows. Γ elemental analysis value (%): C ₃₉ H ₅₄ N ₃ O ₈ As P Calculated value Actual value C 64.71 64.85 H 7.52 7.56 N 5.81 5.63 Γ [α] ²² _D = -47.6゜ (C = 0.50, DMF) Γ ¹ H-NMR ( _CDCl3 ): δ7.5-6.7 (m,
14H), 4.96 (s, 2H), 4.9-4.4 (m, 2H),
4.3-3.7 (m, 5H), 3.3-2.6 (m, 4H), 1.9
~1.0 (m, 3H), 1.40 (s, 9H), 1.27 (t,
3H, J = 7Hz), 1.23 (t, 3H, J = 7Hz),
1.0-0.6 (m, 6H) Based on the above data, the powder was identified as the title compound. Example 2 N-(N-acetyl-L-isoleucyl-L-
Phenylalanyl)-(R)-(-)-1-amino-2-(4-benzyloxyphenyl)ethylphosphonic acid diethyl ester N-acetyl-L-isoleucine 182mg
(1.05mmol), N-L-phenylalanyl-(R)
-(-)-1-Amino-2-(4-benzyloxyphenyl)ethylphosphonic acid diethyl ester hydrochloride 547 mg (1.0 mmol) and 1-hydroxybenzotriazole 142 mg (1.05 mmol) were dissolved in 5 ml of THF. The mixture was cooled to about -10°C in a dry ice/ice bath while stirring. Add 0.115 ml (1.05 mmol) of N-methylmorpholine to this solution and then add 217 mg of DCC.
(105 mmol) in THF (1 ml) was added dropwise.
After raising the reaction solution to 0°C over about 2 hours,
Stirred at room temperature overnight. The precipitated N,N'-dicyclohexylurea was filtered off, and the filtrate was diluted with 50% chloroform.
The resulting homogeneous solution was washed with a 5% aqueous sodium hydrogen carbonate solution, a 5% aqueous citric acid solution, and then a saturated saline solution (3 x 20 ml each). The organic layer was dried over anhydrous sodium sulfate, and the solvent was removed under reduced pressure to obtain 655 mg of a white solid. Recrystallized from chloroform-diethyl ether to give 554 mg (83%) of white crystals.
I got it. The physicochemical data of this compound are as follows. Γ Melting point 194-197.5℃ Γ [α] ¹⁶ _D = -47.8° (C = 0.478, methanol) Γ ¹ H-NMR (CDCl ₃ ): δ7.33 (s, 5H), 7.3 ~
6.7 (m, 9H), 4.97 (s, 2H), 4.9~4.3 (m,
2H), 4.3-3.8 (m, 5H), 3.3-2.6 (m, 4H),
1.94 (s, 3H), 1.9~1.0 (m, 3H), 1.27 (t,
3H, J = 7Hz), 1.23 (t, 3H, J = 7Hz),
1.0 to 0.6 (m, 6H) ΓMS (30eV): m/z 665 (M ⁺ ) ΓIR (KBr): 3340, 2930, 1640, 1625, 1570,
The crystal was identified as the title compound from the data of 12401045, 1020, 970 cm ^-1 or higher. Example 3 N-(L-acetyl-L-isoleucyl-L-
alanyl)-(R)-(-)-1-amino-2-(4
-benzyloxyphenyl)ethylphosphonic acid diethyl ester N-acetyl-L-
Isoleucine and NL-alanyl-(R)-(-)-
1-amino-2-(4-benzyloxyphenyl)
The title compound in the form of white crystals was obtained from ethylphosphonic acid diethyl ester hydrochloride. Γ Melting point 199.5-202.5℃ Γ[α] ²¹ _D = 38.5° (C = 0.20, methanol) ΓMS (20eV): m/z 590 (M ⁺ +1) Example 4 N-(N-acetyl-L-isoleucyl- L-
isoleucyl)-(R)-(-)1-amino-2-
(4-benzyloxyphenyl)ethylphosphonic acid diethyl ester N-acetyl-L-
Isoleucine and NL-isoleucyl-(R)-
The title compound in the form of white crystals was obtained from (-)-1-amino-2-(4-benzyloxyphenyl)ethylphosphonic acid diethyl ester hydrochloride. Γ Melting point 235.0-236.8℃ Γ [α] ¹⁶ _D = -50.0° (C = 0.504, methanol) Example 5 N-(N-acetyl-L-isoleucyl-L-
isoleucyl)-(R)-(-)1-amino-2-
(4-Hydroxyphenyl)ethylphosphonic acid N-(N-acetyl-L-isoleucyl-L-
isoleucyl)-(R)-(-)-1-amino-2-
To 130 mg of diethyl (4-benzyloxyphenyl)ethylphosphonate were added 0.46 ml of anisole and 2 ml of a 25% hydrogen bromide/acetic acid solution, and the mixture was stirred at room temperature for 4 hours.
Removal of volatiles under reduced pressure gave an orange oil. 5 ml of ethyl ether was added for trituration, and the supernatant liquid was discarded. Repeat this operation 5 times,
An orange solid was obtained. Recrystallization from methanol-chloroform gave 86 mg (84%) of pale yellow crystals. The analytical values and physicochemical data of this compound are as follows. Γ elemental analysis value (%): C ₂₂ H ₃₆ N ₃ O ₇ Calculated value Actual value C 54.43 54.24 H 7.47 7.54 N 8.65 8.52 Γ melting point 300℃ or higher Γ [α] ¹⁵ _D = -86.0° (C = 0.10 , methanol) Γ ¹ H-NMR (D ₂ O-NaOD, DSS internal standard): δ7.2-6.5 (m, 4H), 4.12 (d, 1H, J=
8.3Hz), 3.99 (d, 1H, J=8.9Hz), 3.3~2.4
(m, 2H), 2.01 (s, 3H), 1.9~1.0 (m, 6H),
1.0~0.4 (m, 12H) ΓIR (KBr): 3280, 2960, 1640, 1550, 1220,
The crystal was identified as the title compound based on the data of 1000 cm ^-1 or higher. Example 6 N-(N-acetyl-L-isoleucyl-L-
alanyl)-(R)-(-)-1-amino-2-(4
-Hydroxyphenyl)ethylphosphonic acid N-(N-acetyl-L-isoleucyl-L-alanyl)-(R)-
The title compound in the form of a pale yellow powder was obtained from (-)1-amino-2-(4-benzyloxyphenyl)ethylphosphonic acid diethyl ester. Γ Melting point 222-224℃ Γ [α] ²¹ _D = -66.5° (C = 0.20, methanol) Example 7 N-(N-L-isoleucyl-L-phenylalanyl)-(R)-(-)1-amino -2-(4-
Hydroxyphenyl)ethylphosphonic acid N-(N-t-butoxycarbonyl-L-isoleucyl-L-phenylalanyl-(R)-(-)-
1-amino-2-(4-benzyloxyphenyl)
Dissolve 522 mg of ethylphosphonic acid diethyl ester in 1.56 ml of anisole and 2 ml of acetic acid, and add 25 mg to this solution.
% hydrogen bromide/acetic acid solution was added, and the mixture was stirred at room temperature for 5 hours. Removal of volatiles under reduced pressure gave a pale yellow solid. When propylene oxide was added dropwise to a homogeneous solution of this solid in DMF (2 ml), a white precipitate was obtained. This was filtered, washed with methanol and ethyl ether (2 x 3 ml each), and dried under reduced pressure to obtain 272 mg (79%) of a white powder. The physical data of this compound are as follows. Γ Melting point 278-281℃ (decomposition) Γ [α] ²⁴ _D = -100.5° (C = 0.20, 1N NaOH) Γ ¹ H-NMR (D ₂ O-NaOD, DSS internal standard):
δ7.1~6.4 (m, 8H), 4.62 (q, 1H), 4.04 (dt,
1H, J=3Hz, 13Hz), 3.3 to 2.9 (m, 3H),
2.9-2.25 (m, 2H), 1.7-0.5 (m, 9H) From the above data, the powder was identified as the title compound. Reference Example 1 (±) Diethyl 1-amino-2-(4-benzyloxyphenyl)ethylphosphonate [a] The title compound was synthesized according to the following reaction formula. Each step will be explained in detail. (1) 4-benzyloxyphenylacetic acid [4-hydroxyphenylacetic acid] 291g
(1.91mol) to 161g of sodium hydroxide
(4.02 mol) was added to a mixture of 250 ml of water and 800 ml of ethanol to form a homogeneous solution. 240 ml (2.00 mol) of benzyl bromide was added dropwise to this solution at room temperature.
The mixture was stirred overnight. The precipitated white crystals were separated by filtration, washed with 200ml of concentrated hydrochloric acid and then with 300ml of water, and heated at 80°C.
It was dried under reduced pressure to obtain 411 g of white crystals (yield -1). On the other hand, add 500ml of concentrated hydrochloric acid to the filtrate, filter out the white precipitate, wash with 2000ml of water,
It was dried under reduced pressure at °C to obtain 50 g of white crystals (yield -2). Yield - A total of 461 g (99.4%) of 1 and 2 was obtained. Γ Melting point 121-123℃ Γ ¹ H−NMR (CDCl ₃ ): δ10.9 (bs, 1H), 7.4
~6.7 (m, 4H), 7.33 (s, 5H), 5.00 (s,
2H), 3.53(s, 2H) (2) 4-benzyloxyphenylacetylphosphonic acid diethyl ester [] 460 g (1.90 mol) was added to 800 ml of dehydrated (P ₂ O ₅ ) chloroform, and then 415 ml of thionyl chloride (5.70 mol) was added dropwise. After stirring this mixed solution at room temperature for 3 hours, volatile substances were removed under reduced pressure to obtain a pale yellow oil [], which was used as it was in the next reaction. Note that white crystals were obtained by taking a portion of this oily substance, washing it with n-hexane, and drying it under reduced pressure. []: Melting point 71-73.5℃; ¹ H-NMR (CDCl ₃ )
δ7.4~6.7 (m, 4H), 7.35 (s, 5H), 5.00
(s, 2H), 4.00 (s, 2H) [] toluene (500ml) under nitrogen atmosphere
The solution was stirred in an ice bath, and 425 ml (2.47 mol) of triethyl phosphite was added dropwise thereto, and the temperature of the reaction solution was returned to room temperature over 3 hours. When 1000 ml of n-hexane was added to the reaction solution, white crystals were precipitated. Filter this and add n-hexane 2000
After washing with ml and drying under reduced pressure, 465g of white crystals were obtained.
(67.4%). Γ Melting point 111.5-113℃ Γ ¹ H−NMR (CDCl ₃ ): δ7.8-6.7 (m, 4H),
7.33 (s, 5H), 6.00 (d, 1H, J=12Hz),
5.03 (s, 2H), 4.17 (m, 4H), 1.33 (t,
6H, J=7Hz) (3) 428 g (1.18 mol) of 4-benzyloxyphenylacetylphosphonic acid diethyl ester oxime [] was added with 1200 ml of ethanol and 400 ml of water to form a homogeneous solution. Add to this 101g of hydroxyamine hydrochloride
(1.45mol), sodium acetate trihydrate 373g
(2.74 mol) was added and stirred at room temperature overnight. The reaction solution was concentrated under reduced pressure (approximately 1000 ml) and extracted with ethyl ether (3 x 300 ml). The ethyl ether layer was washed with a 5% aqueous sodium bicarbonate solution and then with saturated brine (2 x 100 ml each), and dried over anhydrous sodium sulfate. Removal of the solvent under reduced pressure yielded 441 g (99.1%) of an orange oil. Γ ¹ H-NMR (CDCl ₃ ): δ7.30 (s, 5H), 7.3
~6.7 (m, 4H), 4.98 (s, 2H), 4.4~3.4
(m, 6H), 1.17 (t, 6H, J = 7Hz) (4) (±)-1-Amino-2-(4-benzylooxyphenyl)ethylphosphonic acid diethyl ester [a] In 600 ml of formic acid [ X]441g (1.17mol) was dissolved and stirred under ice-cooling. 350g of zinc powder in this solution
was added little by little to the extent that the temperature of the reaction solution did not exceed 70°C, and the mixture was stirred at room temperature overnight. Insoluble matter in the reaction mixture was filtered off, and the filtrate was concentrated under reduced pressure. Add 500ml of ethyl acetate and saturated brine to the concentrated residue.
300 ml was added and separated into two layers, and the organic layer was collected.
This was washed with a 1N aqueous sodium hydroxide solution and then with saturated brine (3 x 300 ml each), dried over anhydrous sodium sulfate, and the solvent was removed under reduced pressure to obtain 400 g of a pale yellow oil. Since this substance was confirmed by NMR to be a mixture of the target product [a] and the N-formyl compound of [a], the following deformylation and purification were performed. Add a methanol (200 ml) solution of 400 g of the above oily substance to 800 ml of methanol saturated with hydrogen chloride,
Stirred at room temperature overnight. Ethyl acetate was added to the residue obtained by removing volatile substances from the reaction solution under reduced pressure.
500 ml and 300 ml of saturated saline were added, the mixture was separated into two layers, and the organic layer was collected. Add this to a 1N aqueous sodium hydroxide solution (3 x 500 ml) and a saturated saline solution (2 x 250 ml).
The mixture was washed with water, dried over anhydrous sodium sulfate, and the solvent was removed under reduced pressure. Add 300ml of ethyl ether to the residue.
was added and left at -20°C to precipitate white crystals. This was filtered, washed with cold ethyl ether (3 x 150 ml), and dried under reduced pressure to produce 269 g of white crystals.
(63.3%). The total yield from [] is 42.0%
It was hot. The analytical values and physicochemical data of this compound are as follows. Γ elemental analysis value (%): C ₁₉ H ₂₆ NO ₄ Calculated value Actual value C 62.80 62.65 H. 21 7.31 N 3.85 3.86 Γ Melting point 71.5-72.5℃ Γ ¹ H−NMR (CDCl ₃ ): δ7.38 (m, 5H),
7.2-6.8 (m, 4H), 5.04 (s, 2H), 4.16 (m,
4H), 3.19 (m, 2H), 2.63 (m, 1H), 1.34
(t, 6H, J = 7.0Hz) ΓMS (20eV): m/z (relative intensity) 363 (M ⁺ ,
9), 346(7), 226(37), 198(57), 166(100),
138 (15), 91 (28) ΓIR (KBr): 3400, 3000, 1610, 1510, 1240,
Based on the data of 1235, 1055, 1030, 970, 945 cm ^-1 or higher, the crystal was identified as the title compound.

Claims (1)

[Claims] 1. General formula [] [In the formula, R ₁ represents hydrogen, lower alkanoyl or lower alkoxycarbonyl, R ₂ represents lower alkyl or benzyl, R ₃ represents hydrogen or benzyl, and R ₄ represents hydrogen or lower alkyl. however,
When R ₄ is hydrogen, methyl, or ethyl, R ₁ is not acetyl, R ₂ is benzyl, and R ₃ is not hydrogen. ] A phosphorus-containing oligopeptide and a pharmacologically acceptable salt thereof. 2 In the general formula [], -CH(CH ₃ )
The phosphorus-containing oligopeptide and its pharmacologically acceptable salt according to claim 1, wherein the carbon to which CH ₂ CH ₃ , R ₂ and [Formula] are bonded has an optically active configuration. Claim 2, wherein the carbon to which 3 -CH(CH ₃ )CH ₂ CH ₃ and R ₂ are bonded has the S-configuration, and the carbon to which [Formula] is bonded has the R-configuration. The phosphorus-containing oligopeptide and its pharmacologically acceptable salt.