JPH10147571A - Production of n-acyl nitrogen-containing cyclic ketones - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject compound useful as a raw material or intermediate for medicines or agricultural chemicals or as a raw material for enzymes for the biological synthesis of cholesterol. SOLUTION: This method for producing the compound of formula VI (e.g. N-acetyl-4-piperidone) comprises reacting an N-benzyl nitrogen-containing ketone compound of formula I (A is 4-piperidone residue of formula II, 3-piperidone residue of formula III or a 3-pyrrolidone residue of formula IV) with an acid anhydride of formula V (R is an alkyl, an aryl) in the presence of a hydrogen doner such as hydrogen gas, if necessary, in the presence of a catalyst.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing N-acyl nitrogen-containing cyclic ketones, which are compounds useful as raw materials or intermediates of pharmaceuticals and agricultural chemicals. Specifically, N-
The present invention relates to a method for producing acyl-4-piperidone, N-acyl-3-piperidone or N-acyl-3-pyrrolidone.
For example, N-acyl-4-piperidone is used as a raw material for arylidene-1-azacycloalkanes, which are inhibitors of 2,3-epoxysqualene-lanosterol cyclase, which is an important enzyme in cholesterol biosynthesis. (JP-A-6-192256)
issue).

[0002]

2. Description of the Related Art The following method is known as a method for producing N-acyl-4-piperidone. A method in which 4-piperidone hydrochloride is reacted with an acid anhydride or an acid chloride for acylation to obtain a desired product (JP-A-6-1922).
No. 56), a method of converting N-benzoyl-4-piperidine into N-benzoyl-4-piperidinol using a microorganism, and then obtaining the desired product by Jones oxidation reaction with chromic anhydride (J. Org. Chem., 33). Vol. 318
7-3195, 1968).

[0003] As a method for producing N-acyl-3-piperidone, N-benzylpiperidine-3,5-dione is converted to methoxyoxodehydropiperidine in methanol, followed by N-acylation reaction, followed by metal hydride. For obtaining the desired product by a reduction treatment using J. Chin.
Chem. Soc. , 31, 405-407, 19
1984), an N-acyl- obtained by reacting N-acyl-1,4,5,6-tetrahydropyridine with perbenzoic acid.
2-benzoyloxy-3-hydroxypiperidine
A method of obtaining the desired product by thermal decomposition at 40 ° C. (J. Org.
Chem. 37, 2343-2345, 1972.
Year).

As a method for producing N-acyl-3-pyrrolidone, N-acyl-N-carbethoxymethyl-β
-Dickman reaction of alanine ethyl ester to give N
-Acyl-3-carbethoxy-4-pyrrolidone, followed by decarboxylation under acetic acid reflux to obtain the desired product (J. Heterocycll. Chem., Vol. 11,
503-506, 1974).

[0005] However, the above-mentioned method relating to the method for producing N-acyl-4-piperidone easily converts into hydrates because 4-piperidone hydrochloride has a hygroscopic property, and the acid anhydride or acid chloride which is an acylating agent is used. An excess amount of material is required. Further, a base for freeing nitrogen is required,
The operation becomes complicated, for example, a neutralization and washing step occurs during purification. The method requires a special plant because of the use of microorganisms in consideration of industrialization, and the cost is high due to the long manufacturing process. Further, since chromic anhydride is highly toxic, its use may cause deterioration of the working environment.

The above-mentioned method for producing N-acyl-3-piperidone requires a long production step and the yield of the desired product is as low as 31%. In the above method, a great deal of attention must be paid to safety since the reaction is carried out using a peroxide, and the yield of the desired product is as low as 18%.

In the above-mentioned method for producing N-acyl-3-pyrrolidone, the base is used at the time of Dickman condensation, so that the N-acyl bond is easily cleaved, and the decarboxylation step under acetic acid reflux also has a low yield. .

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to provide an N-
It is an object of the present invention to provide a novel method for producing acyl nitrogen-containing cyclic ketones by a simple method in a high yield.

[0009]

Means for Solving the Problems The inventors of the present invention have made intensive studies to solve the above-mentioned problems, and as a result, have continued debenzylation and N-acylation of N-benzyl nitrogen-containing cyclic ketones. Without isolating the intermediate,
The present inventors have found a novel method of obtaining the corresponding N-acyl nitrogen-containing cyclic ketones in a so-called one pot, and have completed the present invention.

That is, the present invention provides a compound represented by the general formula (1):

Embedded image N-benzyl-containing cyclic ketones represented by the general formula (2)

Embedded image (Wherein R represents an alkyl group or an aryl group) by reacting with an acid anhydride represented by the formula (1) in the presence of a hydrogen donor such as hydrogen and, if necessary, a catalyst, particularly a palladium catalyst. 3)

Embedded image (Wherein A and R are the same as those described above). A process for producing N-acyl nitrogen-containing cyclic ketones, characterized by obtaining an N-acyl nitrogen-containing cyclic ketone represented by

In the formulas of the acid anhydride and the target compound of the present invention, R is an alkyl group or an aryl group.
The alkyl group may be linear or branched, and is not particularly limited. For example, a methyl group, an ethyl group,
Examples include an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a t-butyl group, and an n-pentyl group. Examples of the aryl group include a phenyl group and a substituted phenyl group. Examples of the substituent include the above-described alkyl group and a group which is inactive in the reaction of the present invention.

Specific examples of the object in the present invention include:
N-acetyl-4-piperidone, N-acetyl-3-piperidone, N-acetyl-3-pyrrolidone, N-propionyl-4-piperidone, N-propionyl-3-piperidone, N-propionyl-3-pyrrolidone, N- Isobutyryl-4-piperidone, N-isobutyryl-3-piperidone, N-isobutyryl-3-pyrrolidone, N-
(2,2-dimethyl-1-oxopropyl) -4-piperidone, N- (2,2-dimethyl-1-oxopropyl) -3-piperidone, N- (2,2-dimethyl-1-
Oxopropyl) -3-pyrrolidone, N- (1-oxohexyl) -4-piperidone, N- (1-oxohexyl) -3-piperidone, N- (1-oxohexyl)-
3-pyrrolidone, N-benzoyl-4-piperidone, N
-Benzoyl-3-piperidone, N-benzoyl-3-
And pyrrolidone.

Examples of the acid anhydride include acetic anhydride, propionic anhydride, butyric anhydride, isobutyric anhydride, valeric anhydride, isovaleric anhydride, pivalic anhydride, hexanoic anhydride, and benzoic anhydride. Things and the like. The amount of the acid anhydride to be used may be an equimolar amount or more with respect to the N-benzyl nitrogen-containing cyclic ketone, but is preferably 1 to 1.5.
It is twice the molar amount.

Examples of the catalyst include a palladium catalyst, a rhodium catalyst, a Ni catalyst and the like, and a palladium catalyst is particularly preferable. As the palladium catalyst, a heterogeneous catalyst or a homogeneous catalyst can be used as long as the catalyst contains palladium. Examples of the heterogeneous catalyst include those supported on a carrier such as activated carbon, alumina, silica, and barium sulfate. Specific examples thereof include palladium carbon, palladium alumina, palladium silica, and palladium barium sulfate. Examples of the homogeneous catalyst include inorganic salts of palladium such as palladium chloride and palladium bromide, organic salts of palladium such as palladium acetate and palladium benzoate, and di-μ-chlorobis [(η-allyl) palladium (II)]. And palladium complexes such as dichlorobis (acetonitrile) palladium (II). In the case of a heterogeneous catalyst, the amount of the palladium catalyst used (as a palladium atom) is usually 0.05 to 1% by weight, preferably 0.12 to 0.
5% by weight. In the case of a homogeneous catalyst, it is usually 0.5 to 10% by weight, preferably 1.2 to 3% by weight, based on the N-benzyl nitrogen-containing cyclic ketone. Palladium carbon is preferred as a palladium catalyst from the viewpoint of ease of recovery of the catalyst and the amount of the catalyst used.

Examples of the hydrogen donor include hydrogen, formic acid, cyclohexene, and isopropyl alcohol, and a typical one is hydrogen. The pressure of hydrogen is not particularly limited, but is preferably in the range of normal pressure to 10 kg / cm ² . If the hydrogen pressure is too high, the decomposition and excessive reduction of the acid anhydride proceed, and the yield of the target product decreases.

Although the reaction proceeds even without a solvent, the absence of a solvent increases the viscosity of the reaction system, impairs the operability of the post-treatment, and lowers the yield. Therefore, it is preferable to use a solvent. The solvent is not particularly limited as long as it is a solvent inert to the reaction of the present invention. For example, toluene, ethyl acetate, tetrahydrofuran, an organic acid, or a mixture thereof can be used.

The reaction of the present invention is an exothermic reaction, and proceeds favorably at a reaction temperature in the range of about 10 to 60 ° C. If the reaction temperature is low, it is not preferable because a sufficient reaction rate cannot be obtained,
On the other hand, if the temperature is too high, the catalyst is deactivated, which causes a decrease in the yield of the target product.

After completion of the reaction, the desired product can be purified according to a conventional method. For example, after filtering the catalyst and distilling off the solvent from the reaction mixture under reduced pressure, the target product is purified by performing distillation, recrystallization, column chromatography and the like.

[0019]

EXAMPLES The present invention will be described below with reference to examples.
The present invention is not limited thereby.

EXAMPLE 1 100 g (528 mmol) of N-benzyl-4-piperidone, 59 g (578 mmol) of acetic anhydride, 91 g of toluene, and 2.5 g of palladium carbon (containing 5% by weight of palladium) were placed in a 1-liter electromagnetically stirred autoclave. In addition,
The reaction was carried out at a hydrogen pressure of 5 kg / cm ² and 40 ° C. It took 30 minutes to stop hydrogen absorption. After cooling the reaction solution, the catalyst was filtered, the solvent was distilled off by an evaporator, and the residue was purified by distillation to obtain 71 g of N-acetyl-4-piperidone (50 g).
3 mmol, yield 95%, boiling point 125 ° C./1.1 Torr
r) was obtained. NMR spectrum (CDCl ₃ ) δ ppm: 2.20
(3H, s), 2.47 (2H, t), 2.51 (2
H, t), 3.79 (2H, t), 3.88 (2H,
t) Mass spectrum m / e: 141 (M ⁺ ), 113 (b
ase)

Example 2 100 g (528 mmol) of N-benzyl-4-piperidone and 3 parts of acetic acid were placed in a 1-liter electromagnetically stirred autoclave.
After adding 2 g (528 mmol), 59 g of acetic anhydride was added.
(578 mmol), 59 g of toluene and 2.5 g of palladium carbon (containing 5 wt% of palladium), and a hydrogen pressure of 5 g was added.
The reaction was performed at 40 ° C. at kg / cm ² . It took 20 minutes to stop hydrogen absorption. Thereafter, the same treatment as in Example 1 was performed to obtain 67 g (478 mmol, yield 90%) of N-acetyl-4-piperidone.

Example 3 In a 200 ml autoclave, N-benzyl-
7.0 g (37 mmol) of 4-piperidone, 4.2 g (41 mmol) of acetic anhydride, 6.3 g of toluene and 210 mg of palladium acetate were added, and a hydrogen pressure of 6 kg / cm ² , 4
The reaction was performed at 0 ° C. It took 5 hours to stop hydrogen absorption. Thereafter, the same treatment as in Example 1 was performed, and N-acetyl-4-piperidone (5.0 g, 35 mmol, yield 95) was obtained.
%).

Example 4 In a 200 ml autoclave, N-benzyl-
7.0 g (37 mmol) of 4-piperidone, 4.2 g (41 mmol) of acetic anhydride, 6.3 g of toluene and 204 mg of palladium chloride were added, and the hydrogen pressure was 8 kg / cm ² ,
The reaction was performed at 0 ° C. It took 11 hours to stop hydrogen absorption. Thereafter, the same treatment as in Example 1 was carried out, and 4.8 g of N-acetyl-4-piperidone (34 mmol, yield 92)
%).

Example 5 In a 200 ml autoclave, N-benzyl-
5.0 g (26 mmol) of 4-piperidone, 3.0 g (29 mmol) of acetic anhydride, 4.5 g of toluene, and 250 mg of palladium alumina (containing 5 wt% of palladium) were added, and reacted at a hydrogen pressure of 5 kg / cm ² and 40 ° C. . It took 3 hours to stop hydrogen absorption. Thereafter, the same treatment as in Example 1 was performed, and N-acetyl-4-piperidone was obtained.
4 g (24 mmol, 92% yield) were obtained.

Example 6 In a 200 ml autoclave, N-benzyl-
7.0 g (37 mmol) of 4-piperidone, 7.2 g (55 mmol) of propionic anhydride, 5.8 of toluene
g, palladium carbon (containing 10 wt% palladium) 35
0 mg was added, and the reaction was performed at 40 ° C. under a hydrogen pressure of 10 kg / cm ² . It took 1.5 hours to stop hydrogen absorption. Thereafter, the same treatment as in Example 1 was performed, and N-propionyl-
5.5 g of 4-piperidone (35 mmol, 95% yield,
(Boiling point 93 ° C./0.1 Torr). NMR spectrum (CDCl ₃ ) δ ppm: 1.20
(3H, t), 2.40 to 2.51 (6H, m), 3.
77 (2H, t), 3.90 (2H, t) Mass spectrum m / e: 155 (M ⁺ ), 127, 1
12,57 (base)

Example 7 N-benzyl- was added to a 200 ml reaction flask equipped with a magnetic stirrer, condenser, thermometer and balloon.
20 g (106 mmol) of 4-piperidone, 22 g (137 mmol) of isobutyric anhydride, 15 g of toluene, and 0.6 g of palladium on carbon (containing 5 wt% of palladium) were added, and reacted under a hydrogen pressure and a normal pressure at room temperature. It took 22 hours to stop hydrogen absorption. Thereafter, the same treatment as in Example 1 was carried out, and N-isobutyryl-4-piperidone 16 g (9
5 mmol, yield 90%, boiling point 89 ° C./0.08 Torr
r) was obtained. NMR spectrum (CDCl ₃ ) δ ppm: 1.18
(6H, d), 2.49 (4H, t), 2.90 (1
H, sept), 3.86 (4H, br.s) Mass spectrum m / e: 169 (M ⁺ ), 141,1
26, 113, 98 (base)

Example 8 N-benzyl- was added to a 100 ml reaction flask equipped with a magnetic stirrer, a condenser, a thermometer and a balloon.
10 g (53 mmol) of 4-piperidone, 15 g (80 mmol) of pivalic anhydride, 9 g of toluene, and 0.3 g of palladium on carbon (containing 5 wt% of palladium) were added, and the mixture was reacted under a hydrogen pressure and a normal pressure at room temperature. 72 hours before stopping hydrogen absorption
It took time. After cooling the reaction solution, the catalyst was filtered, the solvent was distilled off with an evaporator, and the residue was subjected to a mixed solvent of isopropyl ether and isopropanol (95/5 (V /
V)) for purification by recrystallization, and N- (2,2
-Dimethyl-1-oxopropyl) -4-piperidone 7.0 g (38 mmol, yield 72%, melting point 97.3)
° C). NMR spectrum (CDCl ₃ ) δ ppm: 1.34
(9H, s), 2.47 (4H, t), 3.91 (4
H, t) Mass spectrum m / e: 183 (M ⁺ ), 168, 1
40, 126, 113, 57 (base)

Example 9 N-benzyl- was added to a 100 ml reaction flask equipped with a magnetic stirrer, a condenser, a thermometer, and a balloon.
10 g (53 mmol) of 4-piperidone, 17 g (79 mmol) of hexanoic anhydride, 6 g of toluene, and 0.3 g of palladium on carbon (containing 5 wt% of palladium) were added, and reacted under a hydrogen pressure and a normal pressure at room temperature. 1 to stop hydrogen absorption
It took 6 hours. Thereafter, the same treatment as in Example 1 was performed, and N- (1-oxohexyl) -4-piperidone was used.
6 g (49 mmol, yield 92%, boiling point 115 ° C / 0.
1 Torr). NMR spectrum (CDCl ₃ ) δ ppm: 0.92
(3H, m), 1.35 (4H, m), 1.68 (2
H, m), 2.38 to 2.51 (2H, m), 3.78.
(2H, t), 3.89 (2H, t) Mass spectrum m / e: 197 (M ⁺ ), 168, 1
54, 141, 126, 113 (base)

Example 10 A 100 ml reaction flask equipped with a magnetic stirrer, condenser, thermometer and balloon was charged with N-benzyl-
10 g (53 mmol) of 4-piperidone, 18 g (79 mmol) of benzoic anhydride, 12 g of toluene, and 0.3 g of palladium carbon (containing 5 wt% of palladium) were added, and the mixture was reacted under a hydrogen pressure and a normal pressure at room temperature. 7 to stop hydrogen absorption
It took two hours. Thereafter, the same treatment as in Example 1 is performed, and 8.7 g of N-benzoyl-4-piperidone (43 mmol, yield 81%, boiling point 151 ° C./0.15 Torr)
r) was obtained. NMR spectrum (CDCl ₃ ) δ ppm: 2.50
(4H, br.s), 3.87 (4H, br.s),
7.38 to 7.52 (5H, m) Mass spectrum m / e: 203 (M ⁺ ), 174, 1
46, 105 (base)

Example 11 A 3 ml reaction flask equipped with a magnetic stirrer, a condenser, a thermometer and a balloon was charged with N-benzyl-3-.
2.0 g (10.6 mmol) of piperidone, 1.4 g (13.7 mmol) of acetic anhydride, 1.6 g of toluene, and 60 mg of palladium on carbon (containing 5 wt% of palladium) were added, and reacted at normal pressure and hydrogen pressure at room temperature. . It took 24 hours to stop hydrogen absorption. After cooling the reaction solution, the catalyst was filtered off, the solvent was distilled off with an evaporator, and the residue was subjected to column chromatography (silica gel, ethyl acetate / hexane =
１ ／ (V / V)) and purified by N-acetyl-3-
1.2 g (8.5 mmol, 80% yield) of piperidone were obtained. NMR spectrum (CDCl ₃ ) δ ppm: 1.98-
2.16 (5H, m), 2.52 (2H, t), 3.6
7 (1H, t), 3.75 (1H, t), 4.03 (1
H, s), 4.17 (1H, s) Mass spectrum m / e: 141 (M ⁺ ), 112,8
5 (base)

Example 12 N-benzyl-3 was added to a 30 ml reaction flask equipped with a magnetic stirrer, a condenser, a thermometer and a balloon.
-2.0 g (10.6 mmol) of piperidone, 2.2 g (13.7 mmol) of isobutyric anhydride, 2.5 g of toluene
g, palladium carbon (containing 5 wt% palladium) 60 m
g was added thereto, and the mixture was reacted under normal pressure of hydrogen and room temperature. It took 48 hours to stop hydrogen absorption. After cooling the reaction solution, the catalyst was filtered off, the solvent was distilled off by an evaporator, and the residue was purified by column chromatography (silica gel, ethyl acetate / hexane = 1/3 (V / V)) to give N-isobutyryl- 1.3 g (7.7 mmol, 73% yield) of 3-piperidone were obtained. NMR spectrum (CDCl ₃ ) δ ppm: 1.14
(6H, d), 2.04 (2H, br.s), 2.53
(2H, t), 2.82 (1H, br.s with)
fine coupling), 3.73 (2H, b
r. s with fine coupling),
4.10 (1H, br.s) 4.19 (1H, br.
s) Mass spectrum m / e: 169 (M ⁺ ), 126, 1
13,70 (base)

Example 13 N-benzyl-3 was added to a 30 ml reaction flask equipped with a magnetic stirrer, a condenser, a thermometer and a balloon.
-Piperidone 2.0 g (10.6 mmol), hexanoic anhydride 2.9 g (13.7 mmol), toluene 1.
8 g, palladium carbon (containing 5 wt% palladium) 60
The reaction was carried out under a hydrogen pressure and a normal pressure at room temperature. It took 24 hours to stop hydrogen absorption. After cooling the reaction,
The catalyst was filtered, the solvent was distilled off with an evaporator, and the residue was subjected to column chromatography (silica gel, ethyl acetate / ethyl acetate).
Hexane = 1/4 (V / V)) and purified by N- (1
-Oxohexyl) -3-piperidone 1.9 g (9.6
Mmol, 91% yield). NMR spectrum (CDCl ₃ ) δ ppm: 0.90
(3H, t), 1.32 (4H, br.s), 1.61
(1H, br.s), 1.64 (1H, br.s),
2.03 (2H, sept), 2.30 (1H, t),
2.37 (1H, t), 2.51 (2H, t), 3.6
6 (1H, t), 3.75 (1H, t), 4.03 (1
H, s), 4.19 (1H, s) Mass spectrum m / e: 197 (M ⁺ ), 168, 1
54, 141, 126, 113, 70 (base)

Example 14 N-benzyl-3 was added to a 30 ml reaction flask equipped with a magnetic stirrer, a condenser, a thermometer and a balloon.
-1.0 g (5.7 mmol) of pyrrolidone, 0.7 g (6.9 mmol) of acetic anhydride, 0.8 g of toluene, and 30 mg of palladium carbon (containing 5 wt% of palladium) were added, and the mixture was reacted under a hydrogen pressure and a normal pressure at room temperature. did. It took 20 hours to stop hydrogen absorption. After cooling the reaction solution, the catalyst was filtered off, the solvent was distilled off by an evaporator, and the residue was purified by column chromatography (silica gel, ethyl acetate / hexane = 1/4 (V / V)) to give N-acetyl- 3
-0.6 g of pyrrolidone (4.7 mmol, 82% yield)
I got NMR spectrum (CDCl ₃ ) δ ppm: 2.09
(1.5H, s), 2.11 (1.5H, s), 2.6
4 (1H, t), 2.73 (1H, t), 3.86-
3.98 (4H, m), 4.17 (1H, s) Mass spectrum m / e: 127 (M ⁺ ), 99, 57
(Base)

Example 15 N-benzyl-3 was placed in a 30 ml reaction flask equipped with a magnetic stirrer, a condenser, a thermometer and a balloon.
-Pyrrolidone 2.0 g (11.4 mmol), isobutyric anhydride 2.3 g (14.3 mmol), toluene 1.5
g, palladium carbon (containing 5 wt% palladium) 100
The reaction was carried out under a hydrogen pressure and a normal pressure at room temperature. It took 48 hours to stop hydrogen absorption. After cooling the reaction,
The catalyst was filtered, the solvent was distilled off with an evaporator, and the residue was subjected to column chromatography (silica gel, ethyl acetate / ethyl acetate).
Hexane = 1/3 (V / V)) to give 1.3 g (8.4 mmol, N-isobutyryl-3-pyrrolidone).
(74% yield). NMR spectrum (CDCl ₃ ) δ ppm: 1.15
(3H, d), 1.17 (3H, d), 2.53-2.
82 (3H, m), 3.89 to 4.02 (4H, m) Mass spectrum m / e: 155 (M ⁺ ), 140, 1
27, 57 (base)

Example 16 A 30 ml reaction flask equipped with a magnetic stirrer, a condenser, a thermometer, and a balloon was charged with N-benzyl-3-.
Pyrrolidone 2.0 g (11.4 mmol), hexanoic anhydride 3.1 g (14.3 mmol), toluene 1.6
g, palladium carbon (containing 5 wt% palladium) 60 m
g was added thereto, and the mixture was reacted under normal pressure of hydrogen and room temperature. It took 24 hours to stop hydrogen absorption. After cooling the reaction solution, the catalyst was filtered, the solvent was distilled off with an evaporator, and the residue was purified by column chromatography (silica gel, ethyl acetate / hexane = 1/4 (V / V)) to give N- (1 1.7 g (9.3 mmol, 82% yield) of-(oxohexyl) -3-pyrrolidone were obtained. NMR spectrum (CDCl ₃ ) δ ppm: 0.89-
0.94 (3H, m), 1.26 to 1.38 (4H,
m), 1.67 (2H, br.s with fine)
coupling, 2.22 to 2.40 (2H,
m), 2.56-2.76 (2H, m), 3.89-
3.97 (4H, m) mass spectrum m / e: 183 (M ⁺ ), 154, 1
40, 127, 112, 57 (base)

[0036]

Industrial Applicability According to the present invention, N-acyl-4-piperidone and N-acyl useful as raw materials or intermediates of pharmaceuticals and agricultural chemicals
A novel production method capable of producing acyl-3-piperidone or N-acyl-3-pyrrolidone from the corresponding N-benzyl compound in a simple and simple manner in a high yield could be provided.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI // C07B 61/00 300 C07B 61/00 300

Claims (2)

[Claims] 1. A compound of the general formula (1) N-benzyl nitrogen-containing cyclic ketones represented by the general formula (2) (Wherein R represents an alkyl group or an aryl group) in the presence of a hydrogen donor by reacting with an acid anhydride represented by the general formula (3). (Wherein A and R are the same as described above). A method for producing an N-acyl nitrogen-containing cyclic ketone represented by the formula: 2. A compound of the general formula (1) N-benzyl nitrogen-containing cyclic ketones represented by the general formula (2) (Wherein R represents an alkyl group or an aryl group) by reacting with an acid anhydride represented by the formula (3): (Wherein A and R are the same as described above). A method for producing an N-acyl nitrogen-containing cyclic ketone represented by the formula: