JPH0586394B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial application field] The present invention relates to general formula (1):

[Formula, R ⁰ is -H or

[Formula] R ¹ is -H, -CH ₃ ,

【formula】

[Formula] or CH ₂ OR ¹ ′ (R ¹ ′ represents a C ₁ to C ₁₀ alkyl group, cycloalkyl group, or aralkyl group), R ² is -H or -
CH ₃ , R ³ is

[Formula] or -CHR ⁵ -NHR ⁶ (R ⁴ is -H, -CH ₃ , -C ₆
H ₅ CH ₂ , HOC ₆ H ₄ CH ₂ −, −CH ₂ SH, −CH ₂
SCH ₃ , −CH ₂ CH ₂ SH, −CH ₂ CH ₂ COOH or −
CH ₂ CH ₂ CH ₂ NH ₂ , R ⁵ is -H, -CH ₃ , C ₆ H ₅ CH ₂
−, HOC ₆ H ₄ CH ₂ −, CH ₂ SCH ₃ , −CH ₂ SH, −
CH ₂ CH ₂ SH, −CH ₂ CH ₂ COOH or −CH ₂ CH ₂
CH ₂ NH ₂ , R ⁶ represents -H or C ₆ H ₅ CH ₂ COO-). [Prior art] Formula (2):

Pterin-based compounds represented by the formula [Image Omitted] are generally known in a negative sense due to their difficult to handle physical properties and, in particular, their insolubility in virtually all solvents. In the search for freely soluble pterins, it was found that acylation of the amino substituent at the 2-position dramatically increases the solubility of these compounds (P.
Karrer) and Earl Schweitzer (R.
Schwyzer) Helvetica Chimica Acta, 32
Vol. 423, 1949, and DfWolf, RCAnderson, EA Katsuka
Kaczka), SAHarris,
GEArth, P.L.
PL Southwick, R. Mozingo and K. Folkers, Journal of the American Chemical Society, Volume 69, Page 2753;
(see 1947), making operation even easier. Furthermore, these general formulas (3):

[Chemical formula] (wherein R represents an alkyl group, an aryl group, or an aralkyl group)
(2) to regenerate pterin-based compounds (M.Viscontini and H.
HR Weilenmann, Helvetica Chimica Acta, Volume 228, Page 2170,
(see 1958). This simple N-acylation can also be performed by formula (4):

It is also an effective means for elucidating the chemistry of 5,6,7,8-tetrahydropterin, which is represented by Formula (4)
The reduced pterin represented by is extremely unstable to oxygen and difficult to handle as it is. However, acylation of the nitrogen atom at the 5-position yields air-stable and often crystalline compounds (M Visconcini and H. R. Beilenman, Helvetica Quimica Acta, vol. 228, p. 2170, 1958, R.
Brown (R.Brown), M. Josef (M.
Joseph), T.Leigh and M.Swain, Journal of the Chemical Society, Perkin Trans.1,
1003 pages, 1977, and SNGanguly and M. Visconcini's Helvetica Chimica Acta, vol. 65, p. 1090;
(see 1982). When tetrahydropterin is treated with a strong acylating agent such as trifluoroacetic anhydride, all four nucleophilic nitrogen atoms are acylated, giving the general formula (5):

A tetrakis-(trifluoroacetyl) derivative represented by the formula: (wherein R ¹ , R ² , R ³ and R ⁴ represent -COCF ₃ ) is obtained (R. Weber and M. Visconcini Helvetica Chimica Acta, Volume 60, Page 152,
(see 1977). When treated with a weak acylating agent such as acetic anhydride, N(3) is not acylated, N(8) is partially acylated, and R ¹ , R ³ and R ⁴ in general formula (5) are A mixture of triacetyltetrahydropterin in which -COCH ₃ and R ² is -H and bisacetyltetrahydropterin in the general formula (5) in which R ¹ and R ³ are -COCH ₃ and R ² and R ⁴ are -H. (see Earl Weber and M. Visconcini, Helvetica Chimica Acta, Vol. 60, p. 152, 1977). These studies lead to the conclusion that the acylation susceptibility of various nucleophilic nitrogen atoms is in the order of N(5), 2-N, N(8), and N(3) (Earl Weber and (See M. Visconcini's Helvetica Chimica Acta, vol. 60, p. 152, 1977). This is also supported by the fact that the acyl substituents at 2-N, N(8) and N(3) are hydrolytically removed and the 5-acyl group remains unaffected ( Weber and M. Visconcini's Helvetica Chimica Acta, Volume 60, 152.
Page, 1977, and M. Bisconcini and M. Cogchi-Greuter.
Helvetica Chimica Acta, Volume 54, Page 1125,
(see 1971). If the hydrolysis conditions are made more severe, the 5-acyl group is also removed, and the tetrahydropterin compound of formula (4) is again obtained (S.N. Ganguly and M. Visconcini, Helvetica Chimica Acta, Vol. 65, p. 1090, 1982)
(see M. Visconcini and M. Coguchi-Greuter, Helvetica Chimica Acta, vol. 54, p. 1125, 1971). Formula (6):

2'-N-acetyl-6,7-dimethylpterin, represented by
Angier) and D'Avrill Bui Clan (WV
Curran's Journal of Organics
Chemistry, vol. 26, p. 2129, 1961). However, the compound of formula (6) is somewhat unstable to hydrolysis and the acetyl group is partially cleaved in boiling water. [Problem to be solved by the invention] The present inventor has solved the problem by formula (7):

When the 2'-N-isobutyryl derivative represented by the formula was prepared, as expected, it was more soluble in organic solvents than the compound of formula (6). The compound of formula (7) is also more stable than the compound of formula (6), with less hydrolysis to 6,7-dimethylpterin in decimolar amounts of NaOH compared to the compound of formula (6). It took twice as long. When the compound of formula (7) is catalytically hydrogenated using a platinum catalyst in methanol solution, formula (8):

2'-N-isobutyryl-5,6, represented by [Formula]
7,8-tetrahydro-6,7-dimethylpterin was obtained, which could be isolated as the air-stable hydrochloride without losing the isobutyryl group. As measured by NMR spectrum, the 6- and 7-methyl groups in the compound of formula (8) were cis. [Means for solving the problem] Acylation at the 5-position of the compound of formula (8) with various acylating agents in a pyridine solution under mild conditions is selectively carried out, and several interesting new 5-acyltetrahydropterin was obtained. Acylation of the compound of formula (8) with succinic anhydride results in formula (9):

A 5-succinyl derivative represented by the following formula was obtained in good yield. The basic pka of the compound of formula (9) is −1.34
It was measured as ±0.03. The fact that the compound of formula (9) requires such low PH values for protonation excludes the possibility that this compound exists in zwitterionic form. A study of the hydrolysis reaction of the compound of formula (9) showed that the isobutyryl group was selectively removed in ammonium hydroxide at room temperature. The reason for the difference in reactivity between the 2-amino group and the amide function at N(5) lies in the fact that the 2-N conjugates with the carbonyl group at the 4-position to form a vinyl alcohol-like imide system. . On the other hand, the amide functional group in N(5) cannot be conjugated with the 4-carbonyl group,
As it is, it is a simple amide and has high resistance to hydrolysis. Therefore, the 2-N-isobutyryl substituent can be considered as a protecting group that improves solubility for the preparation of 5-acyltetrahydropterin. The compound of formula (9) has a free carboxyl group on the succinyl substituent, which the inventors utilized to bond the amino acid and the tetrahydropterin compound. Amino acids with carboxyl functional groups protected as benzyl esters (L. Zervas, M. Winitz and JP Greenstein ) Journal of Organic Chemistry, Volume 22, 1515
Page, 1957) was found to be most convenient. As a coupling agent, dicyclohexylcarbodiimide (JC
Sheehan) and GPHess
Journal of the American Chemical Society, Vol. 77, p. 1067, 1955) and N-hydroxy-5-norbornene-2,3-dicarboximide (HONB) (M.Fujino ),
S.Kobayashi, M.Obayashi, T.Fukuda.
Fukuda), S. Shinagawa and O. Nishimura, Chemical Pharmaceutical Bulletin, vol. 22,
1857, 1974)).
The yield was optimized by adding imide.
Formula (11):

Formula (12) of a compound represented by: (wherein R represents a hydrogen atom or an alkyl group):

Hydrogenolysis to the carboxylic acid represented by [formula] (wherein R is the same as above) is carried out rapidly in a methanol solution using a palladium catalyst, and finally in a methanol aqueous solution using ammonia. The isobutyryl group is removed and formula (13):

A compound represented by the formula is obtained. The inventors have also found that it is possible to condense an amino acid to the 5-position of tetrahydropterin of formula (8) by acylation through the carboxyl function of the amino acid. To achieve this, equation (14):

[Formula] (wherein, X represents N-hydroxysuccinimide or N-hydroxy substituted succinimide), the amino group is protected as an N-benzyloxycarbonyl derivative, and the carboxyl group forms an N-hydroxyimide ester. (M Fujino, S Kobayashi, M Obayashi, T Fukuda, S Shinagawa and Oh Nishimura, Chemical Pharmaceutical Bulletin, Vol. 22, p. 1857, 1974; ), J.E.
(See JE Zimmermann and FM Callahan, Journal of the American Chemical Society, Vol. 85, p. 3039, 1963). When heated together with the ester represented by formula (14) in a pyridine solution, acylation occurs at N(5) and the formula
(15)：

Tetrahydropterin is obtained. In equation (14), X is

N-Hydroxysuccinimide (G. D. Anderson, G. E. Zimmerman, and F.M. Callahan, Journal of the American Chemical Society, Vol. 85, p. 3039,
(1963) is more suitable for this acylation, since in formula (14)

The corresponding N-hydroxy-5-norbornene-2,3-dicarboximide ester (M Fujino, S Kobayashi, M Obayashi
(see T. Fukuda, S. Shinagawa, and Oh Nishimura, Chemical Pharmaceutical Bulletin, Vol. 22, p. 1857, 1974) reacts slowly, probably due to steric reasons. The N-benzoyloxycarbonyl protecting group is removed by hydrogenolysis and the isobutyryl group is removed by ammonolysis as described above. The pterin compound according to the present invention is used as various intermediates for pterin-related compounds. In particular, from the standpoint of crystallinity and stability, they offer a variety of options as intermediates in reaction steps. The pterin compounds according to the invention may also have increased absorption into cells as such. Next, the present invention will be explained in more detail based on Examples, but the present invention is not limited to these. Example 1 Preparation of ^N2 -isobutyryl-5,6,7,8-tetrahydro-6,7-dimethyl-5-succinylpterin ^N2 -isobutyryl-5,6,7,8-tetrahydro-6,7-dimethyl 3.00 g (9.39 mol) of pterin monohydrochloride monohydrate was added to a solution of 3.00 g (30 mmol) of succinic anhydride in 40 ml of pyridine, and the mixture was stirred at room temperature under an atmosphere of nitrogen for 2 hours. Next, 4 ml of methanol was added, and the mixture was further stirred for 15 minutes. After removing the solvent under reduced pressure, the oily residue was extracted with hot ether until a solid was obtained. The resulting solid was crushed in ice water with a pH of 1, the insoluble solid was collected, washed with water, and dried to give ^N2 -isobutyryl-5,6,7,8-tetrahydro-6,7-dimethyl- 280 g of 5-succinylpterin (melting point: 163-164°C) was obtained (yield: 86%). This was recrystallized from methanol/water to give the monohydrate. Example 2 N-{4-(N ² -isobutyryl-5,6,7,
Preparation of benzyl ester of 8-tetrahydro-6,7-dimethylpterin-5-yl)-1,4-dioxobutyl}-glutamic acid ^N2 -isobutyryl-5,6,7,8-tetrahydro-6,7-dimethyl- 1.10 g (3.0 mmol) of 5-succinylpterin, 1.486 g (3.31 mmol) of glutamic acid dibenzyl ester monotosylate and 589 mg (3.31 mmol) of N-hydroxy-5-norbornene-2,3-dicarboximide in 30 ml of dichloromethane. The mixture was cooled to 0°C. Next, triethylamine 334
mg (3.31 mmol) was added and stirring continued for an additional 15 minutes. Dicyclohexylcarbodiimide 682mg
(3.31 mmol) at 0°C for 2 hours.
Stirring was continued for 21 hours at room temperature. The precipitated dicyclohexylurea was filtered off and washed with dichloromethane (2 x 10ml). Dry the filtrate,
The residue was taken up with 200ml of ethyl acetate. This solution was mixed with 4% NaHCO ₃ (2 x 25 ml), 0.2 M HOAc aqueous solution (2 x 50 ml), 4% NaHCO ₃ aqueous solution (2 x 25 ml).
and water (2 x 25 ml). _Na2
After drying with _SO4 , the solvent was removed and the residue was chromatographed on silica gel in chloroform/chloroform.
Elution was performed with methanol (9:1). When the solvent is removed, a colorless solid foam (melting point: 184-185℃) 1.624
g (yield: 80%). These were further recrystallized from ethyl acetate/ether to give a colorless solid. Example 3 N-{4-( ^N2 -isobutyryl-5,6,7,
Production of 8-tetrahydro-6,7-dimethylpterin-5-yl)-1,4-dioxobutyl}-glutamic acid N-{4-(N ² -isobutyryl-5,6,7, 8-tetrahydro-6,7-
Benzyl ester of dimethylpterin-5-yl)-1,4-dioxobutyl}-glutamic acid
1.11 g (2.24 mmol) was dissolved in methanol at room temperature and pressure using 100 mg of palladium catalyst (5% in carbon).
Hydrogenolysis was carried out in 50 ml for 5 hours. The catalyst was filtered off and the filtrate was dried. Pour the residue into methanol 10
Dissolve the resulting solution in 100 ml of ether.
A precipitate was generated by dropping into ml. The precipitate was collected, washed with ether and dried. Yield is 770mg, yield is 95%, melting point is 220-221℃ (decomposition)
It was hot. Recrystallization from a small amount of an aqueous solution of 0.1M HC gave colorless crystals. Example 4 N-{4-(5,6,7,8-tetrahydro-
6,7-dimethylpterin-5-yl)-1,
Production of 4-dioxobutyl}-glutamic acid N-{4-(N ² -isobutyryl-5,6,7,8-tetrahydro-6,7-) selected in Example 3
Dimethylpterin-5-yl)-1,4-dioxobutyl}-glutamic acid 700 mg (1.42 mmol)
Dissolve in 3 ml of methanol and add 3 ml of concentrated ammonia water.
Added ml. The resulting solution was stirred at room temperature under a nitrogen atmosphere for 8 hours and then dried. The residue was dissolved in 20 ml of methanol and acetone was added to form a precipitate. The precipitate was collected, washed with acetone and dried. Yield is 600mg, yield is 92%, melting point is 261
~262°C (decomposition). Recrystallization from a small amount of 0.1 M HC aqueous solution gave colorless crystals. Example 5 5-(2'-N-benzyloxycarbonylaminoacetyl) ^-N2 -isobutyryl-5,6,
Preparation of 7,8-tetrahydro-6,7-dimethylpterin 1.00 g (3.13 mmol) of monohydrate of ^N2 -isobutyryl-5,6,7,8-tetrahydro-6,7-dimethylpterin monohydrochloride and N-hydroxysuccinimide ester of N-benzyloxycarbonylglycine 1.92 g (6.27 mmol)
was added to 20 ml of pyridine and the mixture was heated at 60° C. for 2 hours and at 80° C. for 1 hour under nitrogen atmosphere.
Next, 4 ml of methanol was added, and the mixture was further stirred for 15 minutes. After cooling to room temperature, the reaction mixture was dried to dryness.
The residue was co-evaporated with toluene (3x25ml). The residue was taken up with 100 ml of chloroform and the solution was dissolved in 4% aqueous _NaHCO3 (2 x 25 ml), 0.2 M HOAc.
aqueous solution (2 x 50 ml), 4% NaHCO ₃ aqueous solution (2 x
25 ml) and water (2 x 25 ml).
After drying over Na ₂ SO ₄ the solvent was removed and the residue was chromatographed on silica gel with an eluent of methanol/chloroform (1:9). Removal of the solvent gave a foamy solid, which was dissolved in ethyl acetate/
Recrystallization from ether gave a colorless solid. The yield was 1.14 g, yield 80%, melting point 152-154°C (decomposition). Example 6 5-(2'-aminoacetyl) ^-N2 -isobutyryl-5,6,7,8-tetrahydro-6,7-
Production of dimethylpterin 5-(2'-N-benzyloxycarbonylaminoacetyl)-2'-isobutyryl-5,6,7,8-tetrahydro-6,7- obtained in Example 5
560 mg (1.23 mmol) of dimethylpterin was hydrogenolyzed with palladium (5%, 50 mg) in carbon in 20 ml of methanol at room temperature and pressure for 5 hours. The catalyst was removed by filtration, and the volume of the filtrate was 5 ml.
It was concentrated to become. Pour the resulting solution into ether.
A precipitate was generated by dropping into 100 ml.
The precipitate was collected, washed with ether and dried. The yield was 360 mg, yield 91%, melting point 252-254°C (decomposed). The monohydrochloride salt was obtained by recrystallization from a mixture of ethanol/0.1M aqueous HC/ether. Example 7 5-(2'-aminoacetyl)-5,6,7,8-
Production of tetrahydro-6,7-dimethylpterin 5-(2'-aminoacetyl) obtained in Example 6
-N ² -isobutyryl-5,6,7,8-tetrahydro-6,7-dimethylpterin 200 mg (0.62
mmol) was stirred in a mixture of 1 ml of concentrated aqueous ammonia and 1 ml of methanol under a nitrogen atmosphere at room temperature for 8 hours. The solvent was then removed under reduced pressure, the residue was dissolved in 10 ml of methanol, and a precipitate was formed by adding acetone. The precipitate was collected, washed with acetone and dried, the yield was
144mg, yield 92%, melting point 290-291℃ (decomposition)
It was hot. Ethanol/0.1M HC aqueous solution/
The dihydrochloride salt was obtained by recrystallization from a mixture of Et ₂ O.

Claims (1)

[Claims] 1 General formula (1): [Formula] (wherein R ⁰ is -H or [Formula] R ¹ is -H, -CH ₃ , [Formula] [Formula] or CH ₂ OR ¹ '(R ¹ ' represents a C ₁ to C ₁₀ alkyl group, cycloalkyl group or aralkyl group), R ² is -H or -
CH ₃ , R ³ are [formula] or -CHR ⁵ -NHR ⁶ (R ⁴ is -H, -CH ₃ , -C ₆
H ₅ CH ₂ , HOC ₆ H ₄ CH ₂ −, −CH ₂ SH, −CH ₂
SCH ₃ , −CH ₂ CH ₂ SH, −CH ₂ CH ₂ COOH or −
CH ₂ CH ₂ CH ₂ NH ₂ , R ⁵ is -H, -CH ₃ , C ₆ H ₅ CH ₂
−, HOC ₆ H ₄ CH ₂ −, −CH ₂ SCH ₃ , CH ₂ SH, −
CH ₂ CH ₂ SH, −CH ₂ CH ₂ COOH or −CH ₂ CH ₂
A 5N-acyltetrahydropterin compound represented by CH ₂ NH ₂ , R ⁶ represents -H or C ₆ H ₅ CH ₂ COO-. 2. The compound according to claim 1, which is the formula: (R ⁴ is the same as above). 3. The compound according to claim ² , wherein ^R1 is _-CH3 , R2 is _-CH3 , and ^R4 is _-CH3 . 4 R ¹ is -CH(OH)-CH(OH)-CH ₃ , R ² is -
The compound according to claim 2, wherein H and R ⁴ are -CH ₂ CH ₂ COOH. 5 R ¹ is -CH(OH)-CH(OH)-CH ₃ , R ² is -
The compound according to claim 2, wherein H and R ⁴ are [Formula]. 6. The compound according to claim 2, 3, 4 or 5, wherein R ⁰ is -H. 7. The compound according to claim 1, which is the formula: (R ⁵ and R ⁶ are the same as above). 8. The compound according to claim 7, wherein R ¹ , R ² and R ⁵ are -CH ₃ and R ⁶ is -H. 9 R ¹ is -CH(OH)-CH(OH)-CH ₃ , R ² is -
8. The compound according to _claim 7, wherein H and ^R5 are _-CH2CH2COOH , and ^R6 is -H. 10 R ¹ and R ² are -CH ₃ , R ⁵ and R ⁶ are -H
The compound according to claim 7, which is 11. The compound according to claim 7, wherein R ¹ is -CH(OH)-CH(OH)-CH ₃ , R ² and R ⁶ are -H, and R ⁵ is [Formula]. 12 Claim 7, in which R ⁰ is -H,
A compound according to item 8, 9, 10 or 11.