JPS6157536A - Preparation of 2-nitro-4,6-dichloro-5-ethylphenol - Google Patents

Abstract

PURPOSE:To obtain the titled compd. in high yield without separating intermediates, by sulfonating a 3-ethylphenol as a starting material with an excess amt. of concd. sulfuric acid, chlorinating the sulfonation product with Cl2, etc., and substituting the nitro group for sulfo group with nitric acid. CONSTITUTION:3-Ethylphenol or 4-chloro-5-ethylphenol expressed by formula VII(X is H or Cl) is sulfonated with anhydrous sulfuric acid complex in a halohydrocarbon solvent or with an excess amt. of concd. sulfuric acid to give a compound expressed by formula VIII, whichis then chlorinated with Cl2 gas or sulfuryl chloride to give a compound expressed by formula IX. Nitro group is then substituted for the sulfo group with nitric acid to give the titled compound expressed by formula I. EFFECT:Nitro group is introduced selectively producing less isomers. USE:A raw material for providing 2-amino-4,6-dichloro-5-ethylphenol hydrochloride useful as an intermediate for cyano type color formers easily in high yield.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for producing λ-nitroμ, 6-dichloro-j-ethylphenol.

(Background technology) 2-nitro-Hiroshi, 6-dichlor-! -Ethylphenol hydrochloride obtained by reducing and salt-forming ethylphenol according to a conventional method,
It is a useful compound as an intermediate for cyan coloring agents.

The present inventor initially considered the following method for producing 2-amino-≠,6-dichloro-monoethylphenol hydrochloride. That is, ≠−Kuroro! - Ethylphenol (I) is nitrated with nitric acid in glacial acetic acid to give Kohnitro-Chloro-5-ethylphenol (II). Next, this compound (II) was catalytically reduced in dioxane or tetrahydrofuran using Raney nickel as a catalyst under pressure to give λ-amino-chloro-ethylphenol (III), ! −
L, immediately diacetylated with acetic anhydride, co-acetaminol-chloride and monoethylphenol (IV) and separated. Further, compound (IV) was chlorinated with sulfuryl chloride in dioxane to give λ-acetaminohiro, 6-dichloro-! -ethylphenol (V), and then heated with concentrated hydrochloric acid to obtain the target product, λ-aminohiro, 6-dichloro-ethylphenol hydrochloride (
M) is obtained.

However, this method has many drawbacks. First, the yield is extremely low. That is, the yield from compound (I) to (n) is ≠7%, the yield from compound (U) to compound (IV) is 7%, and the yield from compound (IV) to compound (
The total yield from the raw material Hiro-chloro-ethylphenol to the target Niamino-Hiro, Otsu-dichloro-ethylphenol hydrochloride is 2♂.

In the λth nitration step, an isomer having a nitro group at the 6-position is produced in approximately the same amount as the target product, so it is necessary to separate the target product and remove by-products.

Furthermore, an acetylation step is required as a preliminary step to protect the amino group. Third, in the reduction process, the next step involves acetylation with acetic anhydride, so common alcohols cannot be used as solvents, and expensive dioxane,
Tetrahydrofuran etc. must be used. In addition, intermediates according to this method need to be removed a total of λ times after nitration and after acetylation.

(Object of the Invention) Therefore, the object of the present invention is to provide a method for producing λ-amino≠,6-dichloro-monoethylphenol hydrochloride easily and in high yield. Another object is to provide an economically advantageous λ-amino-1A, 6-dichloro-ethylphenol hydrochloride.

(Structure of the Invention) As a result of various studies in order to eliminate the drawbacks of the production method as described above, the present inventor discovered that 2
-Amino-μ・6-dichloro-! -We have completed a new and useful method for producing ethylphenol hydrochloride.

The present invention provides Hiro-chloro-oethylphenol or 3
- ethylphenol in a halogenated hydrocarbon solvent using a sulfuric anhydride complex or in an excess of concentrated sulfuric acid;
Sulfonation gives λ-sulfo≠-chloro-1-ethylphenol or C, Ni-sulfo-1-ethylphenol, which is then chlorinated using chlorine gas or sulfuryl chloride to give co-sulfo μ, 6-dichloro-! -ethylphenol, and then substituted the sulfone group with a nitro group to give λ-nitroψ, t-dichloro! - A method for producing ethylphenol.

Examples of the halogenated hydrocarbon used as a solvent for sulfonation with an anhydrous sulfuric acid complex in the present invention include methylene chloride, chloroform, carbon tetrachloride, dichloroethane,
These include trichlorethylene, tetrachloroethane, tetrachloroethylene, methylchloroform, dibromoethane, trichlorotriflorethane, bromobutane, and the like.

In addition, sulfuric anhydride complexes include sulfuric anhydride and dioxane,
Known complexes with diethylamine, pyridine, etc. can be mentioned. In the case of dioxane complex of sulfuric anhydride, the molar ratio is 2:/
The one is especially good. It is particularly advantageous to use sulfuric anhydride in an amount of 1 to 7 times the mole of ψ-chloro, monoethylphenol or c,3-ethylphenol. Furthermore, since the reaction temperature affects the reaction rate, it is advantageous to carry out the reaction at zo 0c or higher.

When sulfonation is carried out using concentrated sulfuric acid, the sulfuric acid is used in a 3 to 7 molar excess relative to the starting compound, and the reaction temperature is
, 100''C.

The chlorination step is carried out subsequent to the sulfonation step. Conventional means such as passing chlorine gas through the reaction solution are applied. If the reaction temperature in this case is too high, by-products may be produced, so it is desirable that the reaction temperature be ←00C or less, particularly about 0C to JjoC. Additionally, sul7lyl chloride can also be used in this step.

After the completion of the chlorination step, by pouring the reactants into water,
The target substance migrates into the aqueous phase. Therefore, this operation removes the cine fines.

Substitution of a sulfone group with a nitro group can be carried out according to a conventional method. For example, nitric acid may be added to the water extract.

The process of producing co-amino≠,6-dichloro-monoethylphenol chlorine salt by applying the method of the present invention is as follows, for example.

Here, 2-dichloro-6-dichloro-ethylphenol (X) is reduced to 2-amino-hiro, 6-dichloro-! The step of converting compound (XI) into -ethylphenol (X[) and the step of converting compound (XI) into the target compound, 6-dichloro-ethylphenol hydrochloride (Vl), can both be carried out according to conventional methods. Using this method, the yield of target product (VI) t from raw material (■) is 40%
This method is superior to the methods described above.

Furthermore, since nitration is carried out in the form of selective substitution of sulfone groups, isomers are less likely to be produced. In addition, in the chlorination step, the unreacted monochloride undergoes reduction and salt-forming steps to become salt, which is easily soluble in alcohol and is therefore separated and removed in the salt-forming step. In addition, inexpensive alcohols can be used as solvents for the reduction process;
It has the advantage that there is no need to take out intermediates from raw materials until nitration.

(Examples) Next, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited in any way by the following Examples.

Example 1 5 otts of 1,2-dichloroethane and 2 y of dioxa! ,
Four samples of sulfuric acid 21 were placed in a flask, and sulfuric anhydride 11-27 was added dropwise while cooling to below λj0C. Then, in the mixture, ≠-chloro-1-ethyl 7x/-ru t r ,/
f was dissolved in J0rrtl (DI-J-C/Cl ethane and added. After that, it was stirred for 1 hour while maintaining the temperature at 20°C. When it was cooled to 20°C, crystals of the sulfone compound were precipitated, and these were added to water 7. Next, while keeping the temperature at 3o'C, chlorine gas was introduced in an amount of about /, / times the theoretical value.After the blowing of chlorine gas was completed, the mixture was stirred for 3 hours, then put into the apparatus, and the mixture was poured into 2 glasses of water. Go, in a solution of concentrated sulfuric acid≠2.If,
It was added below JO0C. Remove the lower solvent layer, keep the aqueous layer at 2 to 0 ~ zo'c, stir, and add tλ nitric acid,
When the mixture was added dropwise and cooled for 1 hour below s'C, 2-nitro-hydrogen, 6-dichloro-ethylphenol was precipitated. The crystals were collected, washed with water, and dried. Yield 77, jf (yield 7j, 3chi), melting point ≠ 6.3 ~ Hiro 7
．． 3°01 elemental analysis: Actual value H: 3.03chi, C:
Hiroo, s tachi, N: z, it%, calculated value H: J, 5'ri%, C: go.

7z%, N:t, ri 3 Example 2 /, /, 2. Coachtrachlorethane 300? , dioxane λ! , 2f, sulfuric anhydride IA2f and g -chloro-
2-Nitro-Hiroshi, 6-dichloro-Yo-ethylphenol was obtained in the same manner as in Example 1 using Yo-ethylphenol 6r and lf. Yield 7J.

Example 3 Same as Example 1 except that dioxane≠32 was used.
1-Nitrohiro, A-cyclo-1-ethylphenol was obtained. Yield 7/, 7% Reference example isopropyl alcohol! 2yo-, λ-nitro≠16
- dichloro - ethylphenol 12j9 and Raney nickel 7, charged in -ft-/no autoclape;
The initial pressure of hydrogen was set at 10 ki/an, and stirring was continued at 00C or less until the theoretical amount of hydrogen was absorbed. The reaction mixture was filtered to remove the Raney nickel catalyst, and the filtrate was mixed with concentrated hydrochloric acid/l, jf.
was added and stirred for 30 minutes while maintaining the temperature at 0-j-00C to precipitate white crystals. The crystals were cooled for 1 hour at 0°C or less, collected by filtration, washed with acetone lμOM, dried, and converted into λ-aminohiro, t-dichlororu! -Ethylphenol hydrochloride //2. ! I got t. yield? 7. ! H (Embodiments) The present invention also includes the following embodiments.

(1) ψ-chloro-5-ethylphenol Mata, J
-Ethylphenol is sulfonated using a sulfuric anhydride complex in a rhodanized hydrocarbon solvent or in an excess of concentrated sulfuric acid to form 2-sulfo-ψ-chloro, monoethylphenol, or λ-sulfonate. This is ethylphenol, which is chlorinated to give λ-sulfohiro, 6-dichlororu! -ethylphenol and then substituted the sulfone group with a nitro group to give λ-nitro II, A-cycloru! - A method for producing ethylphenol.

In (21+1), a method using Hiro-chloro-Yo-ethylphenol as a starting compound.

(3) A method in which 3-ethylphenol is used as a starting compound in (1).

(4) A method according to (1) using a sulfuric anhydride complex in a halogenated hydrocarbon solvent.

(5) The method in (4), wherein the halogenated hydrocarbon solvent is an aliphatic halogenated hydrocarbon.

(6) The method according to (4), wherein the aliphatic halogenated hydrocarbon is dichloroethane.

(7) A method in which the aliphatic halogenated hydrocarbon is dissolved in tetrachloroethane in (4).

(8) The method according to (4), wherein the sulfuric anhydride complex is a complex of sulfuric anhydride and dioxane.

(9) A method according to (8), wherein the molar ratio of sulfuric anhydride and dioxane is λ;l.

(In 11(1), sulfuric anhydride is added to H-chloro-oethylphenol or 3-ethyl/I/phenol/~i
, a method using z times the molar amount.

C1) A method in which the sulfonation in (1) is carried out using concentrated sulfuric acid in an amount 5 to 7 times the molar amount of the starting compound.

(In 13(1), a method of chlorination using chlorine gas.

(A method in which L3 is set at 2 and 1-2 times the theoretical amount of chlorine gas is used.

(14) (A method performed at less than tso'c in l.

(1!9 Method performed in (14) with λ!0~3t''c.

A method of chlorinating αQ(1) using sulfuryl chloride.

C7) (In 161, a method using 7 to 2 times the theoretical amount of sulfuryl chloride.

(L's (1119, method performed below tILo 0c.

(19 (method performed at 2!~3!0C in 1110).

A method of substituting a sulfone group with a nitro group using nitric acid in 4(1).

C1) Method using 1-2 times the theoretical amount of nitric acid in W.

(23 (method comprising the step of pouring the reactant into water after the chlorination step in 11).

(c) (methods of (2) to (2υ) above in 2z.

(Foundation) Hiro-Chlor-Oethylphenol Mata, 3-
Ethylphenol is sulfonated using a sulfuric anhydride complex in a halogenated hydrocarbon solvent, or in excess concentrated sulfuric acid to give 2-ethylphenol or -sulfo! -ethylphenol;
This is chlorinated to give λ-sulfoψ, 6-dichloro! −
Etherphenol is produced, the sulfone group is replaced with a nitro group to produce 2-dichloro-, 6-dichloro-ethylphenol, and the nitro group is reduced to produce λ-amino, 6-dichloro-ethylphenol. how to.

(c) A method of reducing by catalytic reduction as described in (2) above.

@ Method of using alcohol as a reducing solvent in (c).

＠ The method in which the alcohol is methanol in (to).

How alcohol is an impromptu tool in money (c).

4) Methods of (2) to (c) above in ■ to (c).

(3QIA-chloro-!-ethylphenol or 3-
Ethylphenol is sulfonated using an anhydrous sulfuric acid complex in a halogenated hydrocarbon solvent to give λ-sulfoμmchloro-1-ethylphenol or C,2-sulfo-yo-ethylphenol, which is then chlorinated to i-sulfonate. -Hiroshi,
2-dichlor-! - Ethylphenol, sulfone group replaced with nitro group
yo-ethylphenol and reduced to λ-amino≠, 6
-dichloro-j-ethylphenol and salt formation λ-
Hiroshi Amin, A method for producing 6-dichloro-ethylphenol salt.

01) Method for forming salt using concentrated hydrochloric acid in (to).

A method of producing salt using hydrochloric acid gas in t3 (to).

(c) (To) In ~03, the method of (2) ~ QI above.

(Incorporated) λ-nitro, 4-dichloro-y-ethylphenol produced by the methods (1) to (c) above.

(To) Co-amino-μ, &-cyclo-ethylphenol produced by the above-mentioned method.

(To) λ-Amine-Hiro, 6-dichlororu, produced by the above (To) ~ method! -Ethylphenol hydrochloride.

Patent Applicant Fuji Photo Film Co., Ltd. Procedural Amendment 1, Case Indication Showa! Special Application No. 17 Ri032
No. 2, name of reaction q Konitro Hiroshi, 6-dichlor-
Yo- Ethylphenol manufacturing method 3, relationship with the case of the person making the amendment Patent applicant contact information 10
6 4, 2-26-30 Nishiazabu, Minato-ku, Tokyo Subject of amendment Statement 5. We will submit an engraving of the detailed statement of amendments (with no changes to the content).

Claims (1)

[Claims] 4-chloro-5-ethylphenol or 3-ethylphenol is sulfonated in a halogenated hydrocarbon solvent using a sulfuric anhydride complex or in excess concentrated sulfuric acid to produce 2-sulfo-4-chloro- 5-ethylphenol or 2-sulfo-5ethylphenol, which is chlorinated using chlorine gas or sulfuryl chloride to produce 2-sulfo-4,6-dichloro-5-ethylphenol;
Next, a method for producing 2-nitro-4,6-dichloro-5-ethyl-phenol by replacing the sulfo group with a nitro group using nitric acid.