JPH01216952A - Novel 2-(1-alakylaminoalkyl)-3-hydroxy-1,4-naphthoquinone, production thereof and production of 2-(1-alkenyl)-3-hydroxy-1,4-naphthoquinone - Google Patents

Abstract

NEW MATERIAL:A compound expressed by the formula (R<1> is alkyl or cycloalkyl; R<2> is >=2C alkyl). EXAMPLE:2-(1-Methylaminobuthyl)-3-hydroxy-1,4-naphthoquinone. USE:Useful as a synthetic intermediate for 2-(1-alkenyl)-3-hydroxy-1,4- naphthoquinone and 2-alkyl-3-hydroxy-1,4-naphthoquinone which are intermediates for medicine and agricultural chemical. PREPARATION:2-Hydroxy-1,4-naphthoquinone is reacted with >=3C aliphatic aldehyde in the presence of a primary amine in an inert organic solvent, preferably at <=35 deg.C to provide the compound expressed by the formula. Furthermore, the compound expressed by the formula is thermally decomposed in the presence of an acid to provide the 2-(1-alkenyl)-3-hydroxy-1,4-naphthoquinone.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Applicability 1] The present invention provides novel 2-
(1-alkylaminoalkyl)-3-hydroxy-1
, 4-naphthoquinone, a method for producing the same, and a method for producing 2-(1-alkenyl)-3-hydroxy-1,4-naphthoquinone using the novel compound.

2-(1-alkenyl)-3-hydroxy-1,4-naphthoquinone is a compound with insecticidal and bactericidal activity, and 2-(1-alkenyl)-3-hydroxy-1,4-naphthoquinone is a compound obtained by hydrogenating an alkenyl group. Naphthoquinones are useful as pharmaceuticals, veterinary drugs, and pesticides.

[Prior Art] Conventionally, 2-fulkylaminomethyl-3-hydroxy-1,4-naphthoquinone is produced by reacting 2-hydroxy 1,4-naphthoquinone with formalin and a primary or secondary amine. It is known that it can be easily obtained [M, T, Lef and R1, Hatbaw
ay:J, Amer, Chew, Soc,, Z
L., 3222 (1948)], also.

Reacts with benzaldehyde or acetaldehyde to give 2-(l-alkylaminobenzyl)-3-hydroxy-1,4-naphthoquine or 2-(l-alkylaminoethyl)-3-hydroxy-1,4-naphthoquinone, respectively. The book is known [C, E, Dalglie
sh:J, Amer, Chew, SQC,,LL
107 (1944) and furthermore these compounds have also been investigated for their antimalarial activity. EL, F. Freser and A. R. Richard.
son: J, AIIer, Chew,
SOc, 70°3158 (1948)].

On the other hand, 2-(l-alkenyl)-3-hydroxy-1,
The method for producing 4-naphthoquinone is as follows: (1) 2-hydroxy-1,4-naphthoquinone and several moles of aldehyde are dehydrated and condensed in an acetic acid solvent using about 1.7 moles of hydrochloric acid as a catalyst. Method of manufacturing [J
, Am, Chew, Sac, 5B, pH8
3-11f17 (11136) Go or ■ A method of using triethylamine instead of hydrochloric acid as a catalyst and dimethylformamide or acetonitrile as a solvent in the method of ■ above [J, Che
w, Sac, Perkin Trans, I,
p85fJ~884(In2)] is only known.

[Problem to be solved by the invention] However, 2-(1-alkylaminoalkyl)-
In these reports regarding the production of 3-hydroxy-1,4-naphthoquinone, it was found that when aldehydes other than formalin, benzaldehyde, and acetaldehyde are used, the reaction does not proceed well and a tar-like substance is obtained, or
or 2.2゛-methylenebis-3-hydroxy-1
It has been reported that only ,4-naphthoquinone derivatives are produced, and that 2-(1-alkylaminoalkyl)-3-hydroxy-1,4-naphthoquinone cannot be obtained when an aliphatic aldehyde of 01 or higher is used. However, the scope of application of this reaction was limited.

Also, 2-(toalkenyl)-3-hydroxy-1,4
-The above-mentioned method for producing naphthoquinone using hydrochloric acid as a catalyst requires special equipment materials because hydrochloric acid is an extremely corrosive acid, and although it is not practical as an industrial production method. In addition, in all of these methods, the yield is about 30 to 40 moles, and since a large excess of aldehyde is used, a large amount of aldehyde condensates and other by-products are produced. It has drawbacks such as the complicated method of isolating the target product, so it cannot be said to be an industrially advantageous method.In addition, the method (2) above cannot be said to be versatile, and in most cases Preference is given to the production of °-methylenebis-3-hydroxy-1,4-naphthoquinone derivatives.

[Means for solving the problem] The present inventors have discovered that 2-(1-alkylaminoalkyl)-
As a result of extensive research into the production method of 3-hydroxy-1,4-naphthoquinone, we found that a primary amine and a specific solvent were used for various aldehydes other than formalin, benzaldehyde, and acetaldehyde, and the reaction temperature was increased. By keeping the temperature below 35°C, a new 2-(1-alkylaminoalkyl)-3-
The present invention was completed by discovering that hydroxy-1,4-naphthoquinone can be selectively obtained in high yield, and that depending on the solvent used, the product can be easily isolated as crystals.

Also, 2-(1-fulkenyl)-3-hydroxy-1,
Regarding the production of 4-naphthoquinone, the 2-(toalkylaminoalkyl)-3-hydroxy-1,4-naphthoquinone produced by the above method was treated with an acid such as sulfuric acid or hydrohalic acid in an inert organic solvent. It has been found that 2-(1-flukenyl)-3-hydroxy-1,4-naphthoquinone can be produced by carrying out a thermal decomposition reaction in the presence of 2-(1-flukenyl)-3-hydroxy-1,4-naphthoquinone.

That is, the present invention is based on the general formula (wherein R1 represents an alkyl group or a cycloalkyl group)
A novel 2-(1-alkylaminoalkyl) represented by 2 represents an alkyl group having 2 or more carbon atoms.
-3-hydroxy-1,4-naphthoquinone.

The novel naphthoquinone compound of the present invention comprises inactivating 2-hydroxy-1,4-naphthoquinone (A) and an aliphatic aldehyde having 3 or more carbon atoms (B) in the presence of a primary amine (C). Obtained by reaction in an organic solvent.

By the above method, 2-(1-alkylaminoalkyl)
The reaction to obtain -3-hydroxy-1,4-naphthoquinone (D) is represented by the following reaction formula.

As the aldehyde used in the present invention, an aldehyde R2CHO having 3 or more carbon atoms is used.

Here, R2 represents an alkyl group having 2 or more carbon atoms, preferably 5 to 20 carbon atoms, and is selected depending on R2 of the target compound (D).

The principal aldehydes are, for example, propionaldehyde, butyraldehyde, isobutyraldehyde, valeraldehyde, isovaleraldehyde, pivalaldehyde, capronaldehyde.

Aliphatic saturated aldehydes such as heptylaldehyde, caprylicaldehyde, pelargonaldehyde, capricaldehyde, undecylaldehyde, dodecylaldehyde (lauric aldehyde), tridecylaldehyde, myristicaldehyde, pentadecylaldehyde, margaric aldehyde, stearyl aldehyde, etc. .

The amount of the aldehyde used is based on the raw material 2-hydroxy-1,
Generally 1 or more moles per 4-naphthoquinone, usually 1.
The amount is 0 to 2.0 times by mole, preferably 1.1 to 1.4 times by mole, and if it is less than 9 equivalent moles, the yield will decrease and even at most it is not economical.

The amine RI NR2 used in the above reaction is limited to primary amines such as alkyl amines or cycloalkylamines. For secondary amines and tertiary amines, 2.2°-
Preference is given to the formation of methylenebis-3-hydroxy-1,4-nattoquinone derivatives. This amine may be in gaseous or liquid form, or may be in an aqueous solution, and the RI is also selected depending on the RI of the target compound (D). Generally, primary alkyl amines such as monomethylamine, ethylamine, n-propylamine, i-propylamine, butylamine, t-butylamine, or cycloalkyl 7amides such as cyclohexylamine are mentioned.

The amount of primary amine used is 2-hydroxy-1,
The amount is generally 0.8 to 1.5 moles, preferably 0.3 to 1.1 moles, and more preferably equimolar to 4-naphthoquinone. Whether the amount of amine used is large or small, the yield of the target compound decreases.

Examples of the inert organic solvent used in the reaction include alcohol, cellosolve, dioxane,
(THF), diols, ketones, fatty acid esters, aromatic hydrocarbons (B, T,
Alcohols such as methanol, ethanol and the like are convenient.

Regarding the reaction conditions for the above reaction, it is desirable that the reaction temperature is 35°C or lower, preferably 0 to 30°C.

Particularly preferably, the temperature is 20 to 25°C. If the temperature is too high, the production of the 2.2°-methylbis-3-hydroxy-1,4-naphthoquinone derivative takes priority, and if the temperature is too low, the reaction rate becomes extremely slow and the reaction time is 1 to 10, which is not practical.
Hours are hours and minutes of light.

The above manufacturing method according to the present invention is generally carried out as follows.

After adding a predetermined amount of 2-hydroxy-1,4-naphthoquinone and a primary amine to a predetermined amount of a solvent to generate a primary amine salt of 2-hydroxy-1,4-naphthoquinone, Further, a predetermined amount of aldehyde was added and reacted with stirring at a predetermined temperature for 1 to 10 hours, or a predetermined amount of primary amine and aldehyde were added to a predetermined amount of solvent to generate a Schiff base. Afterwards, a predetermined amount of 2-
Hydroxy-1, tonaphthoquinone is added, and the mixture is allowed to react at a predetermined temperature for 1 to 10 hours while stirring. The precipitated crystals are filtered, and the resulting filter cake is washed with alcohol or the like and dried to obtain 2-(1-alkylaminoalkyl)-3-hydroxy-1,4-naphthoquinone. If necessary, the product can also be recovered from the liquid.

2-(1-alkylaminoalkyl)- in the present invention
By thermally decomposing 3-hydroxy-1,4-naphthoquinone (tl), 2-(l-alkenyl)-
3-hydroxy-1,4-naphthoquinone (F) can be obtained. However, as shown in the following formula, in this case, R2 in compound (D) must represent an alkyl group having 2 or more carbon atoms, and the carbon at the α position must have at least one hydrogen. This thermal decomposition reaction is expressed by the first-order reaction formula, in which 2-(1-alkenyl)-3-hydroxy-1,4-
Naphthoquinone (F) is obtained.

(D) (E) (F) where RI in formula 1 represents an alkyl group or a cycloalkyl group;
2 has the same meaning as the above definition, RN, alkyl, R4:
Water or alkyl, X represents an acid group.

The acid used in the above thermal decomposition reaction is an acid that can react with the 7-mino group of 2-(1-alkylaminoalkyl)-3-hydroxy-1,4-naphthoquinone (D) to form a quaternary ammonium salt. For example, 7X hydrochloric acid such as hydrochloric acid, hydrobromic acid, hydroiodic acid, or sulfuric acid may be used.

The amount of the above acid used is 2-(1-alkylaminoalkyl)
-3-Hydroxy-! , 4-naphthoquinone in an equimolar amount or more, preferably 1.0 to 1.5 times the molar amount. If the amount used is small, side reactions will occur and the yield will decrease.

In addition, if the amount is too large, the reaction will be slow.

Solvents used in the above reaction include glycol ethers such as methyl cellosolve and ethyl cellosolve, aromatic hydrocarbons such as xylene, ethers such as dioxane,
Examples include esters such as butyl acetate, and ketones such as methyl isobutyl ketone.

The reaction conditions include a reaction temperature of 75°C or higher, preferably 80°C or higher.
140℃, normal pressure, pressurization, autogenous pressure, reaction time 0
．． He is a henchman for about 5 to 10 hours.

This thermal decomposition reaction is generally carried out as follows.

A predetermined amount of 2-(1-alkylaminoalkyl)-3-hydroxy! , 4-naphthoquinone is added to a predetermined amount of solvent, and further a predetermined amount of acid is added under stirring at room temperature.

After generating the quaternary ammonium salt, 0.
A thermal decomposition reaction is carried out for 5 to 10 hours. The reaction mixture is cooled and the precipitated crystals are filtered. The resulting filter cake is washed with alcohol and dried to obtain 2-(1
-alkenyl)-3-hydroxy-1,4-naphthoquinone crystals are obtained. In addition, if necessary, 1! ! Further product can be recovered from the solution, for example by concentrating the filtrate and crystallizing it on cooling.

In the hydrothermal decomposition reaction, it is not necessary to use isolated 2-(l-alkylaminoalkyl)-3-hydroxy-1,4-naphthoquinone, and 2-hydroxy-1,4-naphthoquinone and aldehyde are combined with primary Similarly, 2-(1
-Flukenyl)-3-? Crystals of droxy 1,4-naphthoquinone can be obtained.

[Example] Hereinafter, the present invention will be explained in detail by giving examples.

Example 1 2-hydroxy-1,4-naphthoquinone (Lawson)
3.50 g (20.1 mmol) was added to 50% of ethanol, and further aqueous monomethylamine solution (40 tx) was added.
, e.

g (20.8 mmol) was added to make a homogeneous solution of the amine salt, and then 1.90 g (28.4 mmol) of butyraldehyde was added and reacted at 25° C. for 1.5 hours. Approximately 2
After completion of the reaction in which crystals began to precipitate in 0 minutes, the precipitated crystals were filtered off and washed with methanol to obtain 4.43 g (17.1 mmol) of crude crystals of the target product. Yield is 85.
It was 1 mole 2.

Example 2 In place of the methylamine aqueous solution in Example 1, 1.30 g of ethylamine aqueous solution (70 wt.
The procedure was repeated in the same manner as in Example 1, except that the reaction time was 1 hour, and 4.43 g (18
, 2 mmol) was obtained. The yield was 80.7 mol2.

Example 3 n-prolamine instead of ethylamine in Example 2 1.
5.811 g (111, [
1 mmol) was obtained. The yield was 97.3 mol2.

Example 4 2-1-Melamino-3-meroop-3-hydroxy-14-thiquinone d The solvent was changed to 50 ml of methanol, and 2.20 g (25.8 mmol) of isovaleraldehyde was added in place of butyraldehyde. 3.23 g (11.8 mmol) of crude crystals of the target product were obtained in the same manner as in Example 1, except that the reaction time was 3 hours. The yield was 58.9 mol2.

Example 5 3.80 g of caprylic aldehyde (24,4
mmol), amine to cyclohexylamine 2.00g
8.80 g (1111.5 mmol) of crude crystals of the target product were obtained in the same manner as in Example 4 except that the amount was changed to (20.2 mmol). The yield was 82.3 mol2.

Example 6 8.0 Gg (34.5 mmol) of 0-propylamine and 2.06 g (34.5 mmol) of i-propylamine were added to 100 g (34.5 mmol) of i-propylamine, and further added to this in a water bath (27°C).
7.82 g (41.3 mmol) of -dodecylaldehyde was added and reacted for 3 hours. After the reaction, the precipitated crystals were filtered off, washed with methanol, and 2-(+-i-
9.78 g of (propylamine)-3-hydroxy-1,4-naphthoquinone was obtained. The yield was 70 mol2.

Further, as a result of analyzing the filtrate by HPL (high performance liquid chromatography), 0.21 g of unreacted lawson and 2.72 g of the target substance were confirmed in the filtrate. When the target product in this filtrate is added, the yield is 12.48 g (31.2 mmol), and the yield is 80.4 mol2.

Example 7 2.5 n-butylamine instead of 1-propylamine
8.72 g (47 moles) of 2-(1-n-butyl7mino)-3-hydroxy-1,4-naphthoquinone was obtained in the same manner as in Example 6, except that 5 g (34.5 mmol) was used. Ta. Further, as a result of HPLC analysis of the filtrate, 0.11 g of unreacted lawson and 8.57 g of the target product were confirmed. Total yield: 13.29 g (32.1 mmol), yield: 83.0
It was mol 2.

Example 8 2-(
l-t-butylaminododecyl)-3-hydroxy-1
, 4-nafdoquinone 5.8? , obtained. Also, the filtrate is
When analyzed by LC, 242 g of unreacted raw material and 1.49 g of the target product were confirmed. The yield was 7.16 g (17.3 mmol), and the yield was 50.1 mol2.

Example 9 o-Soy 19.7g (113mijj%A/),
40$) Thik 7mine aqueous solution 8.77g (3 mmol) and methanol 300-1 water 20°3g were stirred at room temperature, and to this was added 25.0g n-dodecylaldehyde (1
35.8 mmol) was added and reacted for 3 hours. The precipitated crystals were filtered and washed with methanol to obtain crude crystals of 2-(1-methylaminododecyl)-3-hydroxy-1,4-naphthoquinone 33. Illg (91.4 mmol) (8
0.13 mol 2) was obtained. Further, when the filtrate was analyzed by HPLC, 3.28 g (8.84 mmol) of the target product and 1.45 g (8.33 mmol) of unreacted lawson were confirmed.

Example 10 The solvent was THF instead of ethanol, and 4.44 g (2
The reaction was carried out in the same manner as in Example 1, except that 4.1 mmol) was used, and a portion of the resulting homogeneous solution was analyzed by HPLC.
3-hydroxy-1,4-naphthoquinone 25.3 g (
0.15 mmol). The yield is 89.0 mol2
Met.

The IR ((knee 0 stretching frequency υ, cm'), NMR, and melting point (m, p,) of the compound obtained above are shown in Table 1, and the elemental analysis results are shown in Table 2.

Example 11 2-(1-n-butylaminodode Table 1 Table 2)-3-hydroxy-1,4-naphthoquinone (h) obtained in Example 7
3.34 g (8.09 mmol) was added to methyl cellosolve 30- and then 0.0 g of sulfuric acid was added. +12 g (2 mmol of 8J) was added at room temperature with stirring to make a homogeneous solution of sulfate, and then heated to 120°C and subjected to a thermal decomposition reaction for 1 hour. After the reaction was completed, the resulting reaction solution was cooled. By filtering the precipitated crystals and washing thoroughly with methanol, 2.
-(1-dodecenyl)-3-hydroxy-1,4-naphthoquinone crystals 2.23 g (6,58 mmol) (8
1.1 mol 2) was obtained. In addition, when the filtrate was analyzed by HPL (:), 0.11 g (7) of the product (0.32 mm!
J mol) (4,0 mol ID was confirmed.

Example 12 2-(1-t-butylamimodedodecyl)-3-hydroxy-1,4-naphthoquinone (i
Crystals of 2-(l-dodecenyl)-3-hydroxy-1,4-naphthoquinone were prepared in the same manner as in Example 11, except that 3.32 g (8.04 mmol) of 2. 54 g (7.47 mmol) (92.13 mol 2) were obtained. In addition, when the filtrate was analyzed by HPLC, 1
45 g (0.43 mmol) (5.3 mol2) was confirmed.

Example 13 2-(1-n-butylaminobutyl)-3-hydroxy-1,4-naphthoquinone (c) 3 obtained in Example 3
．． 00g (9.97 mmol) of methyl cellosolve 5o
- 1.15 g of concentrated hydrochloric acid (11,
After the reaction solution was heated to 120°C and kept for 1 hour to carry out a thermal decomposition reaction, the reaction product solution was concentrated under reduced pressure and the obtained The resulting oil was separated and purified using a silica gel column (ethyl acetate: n-hexane = 20), and purified with 2-(1-butynyl).
-3-hydroxy-1,4-naphthoquinone crystals 1.8
5 g (8.11 mmol) (81.4 mol 2) were obtained.

Example 14 In Example 11, 2-(l-butylaminobutyl)
-3-hydroxy-1,4-naphthoquinone was replaced with 2-(l-methylamino-3-methyl-
butyl)-3-hydroxy-1,4-naphthoquinone (d
) 2-(3-methyl-butenyl)-
Crystals of 3-hydroxy-1,4-naphthoquinone 1.30
g (5.37 mmol) (73.3 mol) was obtained.

Example 15 In a 30-glass autoclave, 1.0 Og (2.87 mmol) of 2-(1-methylaminododecyl)-3-hydroxy-1,4-naphthoquinone and 305.8 m of concentrated sulfuric acid were added.
g (1.1 mmol times the raw material) and 20 mm of xylene were added, heated to 120° C. with stirring, and kept at that temperature for 1 hour. After cooling, the mixture was extracted with a benzene-water system, the organic layer was dried over sodium sulfate, the solvent was distilled off, and the mixture was reconstituted with methanol. This results in 2-(
1-Dodecenyl)-3-hydroxy-1,4-naphthoquinone 734.8 Layer 8 was obtained. In addition, the recrystallization filtrate was subjected to HPL.
As a result of analysis by C, 2-hydroxy-1,
4-Naphthoquinone! 2.4 g, raw material 0.7 g, and target material 15.5 g were confirmed. The yield etc. are shown in Table 3.

Examples 16 to 18 The same procedure as in Example 13 was carried out except that the solvent was replaced with the solvent shown in Table 3. However, extraction was performed using an ethyl acetate-water system. The yields obtained are shown in Table 3.

Example 19 Butyl acetate 7 (2-hydroxy-1,4- in 1+ae)
3.52 g (20.2 mmol) naphthoquinone, methylamine (1.80 g 4 oz aqueous solution) (20.8 mmol) and 4.40 g (23.1 mmol) n-dodecylaldehyde.
1 mmol) was reacted at room temperature for 2 hours.

When the obtained reaction solution was analyzed by HPLC, it was 7.28g.
(19 J mmol) of 2-(1-methylaminododecyl)-3-hydroxy-1,4-naphthoquinone was mixed with 2.08 g (20 J mmol) of concentrated sulfuric acid.
, 2 mmol) was gradually added to form a solution of sulfate (
A homogeneous solution was formed at 50° C.), and the thermal decomposition reaction was carried out under reflux for 1 hour.

After the completion of the reaction, the reaction solution was cooled, and the precipitated crystals were filtered out.
5. Crystals of 2-(1-dodecenyl)-3-hydroxy-1,4-naphthoquinone are obtained by washing with methanol.
13g (15,1 mi! J % JLz) (74,8-!
1L4) was obtained, and HPL (: 0.70 g (2,013 mmol) (10.2 mol2) was obtained in the ejected liquid by analysis.
The product was confirmed.

Therefore, in this reaction, 2-(1-dodecenyl)-3-hydroxy-1,4-naphthoquinone is produced by 85. This means that it was synthesized with a high yield of H.

Comparative Example 1 2.5 g of 2-hydroxy-1,4-naphthoquinone (14
, 4 mmol) in acetic acid 501, and further added 5.4 g of dodecylaldehyde (2.03 times the mole of 2-hydroxy-1,4-naphthoquinone) and 7.5 g of concentrated hydrochloric acid.
(1 for 2-hydroxy-1,4-naphthoquinone.
4 mole times) was added as a catalyst, and the mixture was reacted at 85°C for 2 hours. The resulting reaction solution was cooled to about 5°C, but since no crystals precipitated, it was poured into 3001 ml of water and then 20 ml of benzene.
Extracted at 0w+j. Add this organic layer to 1z of sodium carbonate.
After washing twice with 150 d of aqueous solution and 150 d of water, drying with anhydrous sodium sulfate and distilling off benzene, the resulting oil layer was separated and purified using a silica gel column.
l-dodecenyl)-3-hydroxy-1,4-naphthoquinone! , 97g was obtained. The yield was 40.2 mol2.

[Effect of the invention] 2-(1-alkylaminoalkyl) obtained by the present invention
-3-Hydroxy-! , 4-naphthoquinone is thought to have physiological activity in its own right, but it can also be used as a useful pharmaceutical and agricultural intermediate by deamination reaction.
-(l-alkenyl)-3-hydroxy-1, tonaphthoquinone and 2-furkyl-3-hydroxy-1,4-
It can lead to naphthoquinone.

Procedure Nefusho (self-motivated) Engineering 6 March 1985 Tumor Day

Claims (5)

[Claims] (1) General formula ▲ Numerical formula, chemical formula, table, etc. ▼ (In the formula, R^1 is an alkyl group or a cycloalkyl group,
R^2 represents an alkyl group having 2 or more carbon atoms. ) Novel 2-(1-alkylaminoalkyl) represented by
-3-hydroxy-1,4-naphthoquinone. (2) A 2-(
1-alkylaminoalkyl)-3-hydroxy-1,
Method for producing 4-naphthoquinone. (3) 2 according to claim 2, wherein the reaction temperature is 35°C or lower.
-(1-alkylaminoalkyl)-3-hydroxy-
Method for producing 1,4-naphthoquinone. (4) General formula ▲ Numerical formula, chemical formula, table, etc. ▼ (In the formula, R^1 is an alkyl group or a cycloalkyl group,
R^2 represents an alkyl group having 2 or more carbon atoms, and has at least one hydrogen at the α-position carbon. ) Novel 2-(1-alkylaminoalkyl) represented by
2-( characterized by thermally decomposing -3-hydroxy-1,4-naphthoquinone in an inert solvent in the presence of an acid.
A method for producing 1-alkenyl)-3-hydroxy-1,4-naphthoquinone. (5) Claim 4, wherein the acid is sulfuric acid or hydrohalic acid.
2-(1-alkenyl)-3-hydroxy-1 as described in
, 4-naphthoquinone manufacturing method.