JPS5913514B2 - Oxazolyl ethylene powder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention aims to provide an advantageous method for producing arylooxazolylethylene compounds, which are important as fluorescent brighteners or intermediates thereof.

More specifically, general formula (1) (wherein R1 is a hydrogen atom,
It represents a lower alkyl group, a lower alkoxy group or a halogen atom, and R2 represents a hydrogen atom or a dialkylamino group.

) and a Schiff base compound having the general formula (
n) or [formula (11) or 4, where X may have a lower alkoxycarbonyl group or cyano group as a substituent; , R3 is general formula (1)
, but R1 and R3 may be the same or different), Y represents a phenylene group, biphenylene group, or naphthylene group, and R represents a lower alkyl group. or phenyl group.

A general country or (b) (formula (V) or (inner, R1, X and Y is the general formula (1), (11) respectively
and mean the same thing as in shout. ) The present invention relates to a method for advantageously producing a benzoxazolylethylene compound represented by Among the oxazolylethylene compounds represented by the general formula (V) and C which can be obtained by the production method of the present invention, there are many compounds which are important as fluorescent brighteners or intermediates thereof.

For example, the compound of the following formula (b) shown as a typical example is extremely useful as a fluorescent brightener for synthetic fibers, and therefore many manufacturing method patents have been disclosed regarding this compound. There is. A method in which inic acid and two molecules of 2-amino-4-methylphenol (cresamine) are heated in the presence of phosphorus trichloride or phosphorus oxychloride in an inert organic solvent to cause condensation and ring closure. No. 45-2663), a semi-closed ring compound of the formula [ is prepared by condensing cresamine with fumaric acid, maleic acid or malic acid using an iron salt as a catalyst, and this is mixed with a compound such as zinc chloride. There is a method of treating with a ring-closing agent to lead to seagulls (Japanese Patent No. 506283, Japanese Patent Publication No. 42-9791).

However, the compounds obtained by these methods have low melting points, are difficult to recognize as highly pure, and have low yields based on cresamine.

When preparing a compound of the formula by the method of the present invention, the reaction proceeds rapidly under mild conditions, for example at a temperature of 40°C in N-N-dimethylformamide, and the desired product is produced in an extremely pure form ( Melting point: 187-188°C).

For this reason. When using this product as a fluorescent brightener, it is no longer necessary to carry out further purification, and the reaction yield is quantitative, which is very advantageous. Therefore, the method of the present invention is of extremely high value industrially.
When using the method of the present invention, in addition to the bilaterally symmetrical compound such as the above-mentioned formula, the raw material Schiff's base compound (V) and the methanephosphonic acid ester compound 4° (by selecting n or It is also one of the remarkable features of the present invention that any asymmetric oxazolylethylene compound can be synthesized.

General formula (I) which is one of the raw materials used in the production method of the present invention
The Schiff base compound of, for example, contains approximately equimolar amounts of the corresponding benzoxazol-2-ylmethanephosphonic acid diester and nitrosobenzenes in an amount equal to 3 of their total amount.
In an organic solvent such as methanol or dimethylformamide of 1 to 100 times (by weight), in the presence of a basic substance such as sodium hydroxide or metallic sodium in a proportion of 1 to 2 gram equivalents at 5 to 40°C for 10 minutes to 3 hours. It is obtained by reacting and removing crystals of the reaction product precipitated by filtration.

This reaction is shown in the following formula. (In the above formula, A and Ar have the same meanings as in general formula (I), and R1 represents a lower alkyl group or a phenyl group.

) Examples of Schiff base compounds include the following.

Benzoxazol-2-ylmethyleneaniline, benzoxazol-2-ylmethylene-4'-dimethylaniline, 5-methylbenzoxazol-2-ylmethyleneaniline, 5-methylbenzoxazol-2-ylmethylene-4'-dimethylaminoaniline, 6-methylbenzoxazol-2-ylmethyleneaniline,
5-ethylbenzoxazole-2-ylmethyleneaniline, 5-n-propylbenzoxazole-2-
ylmethyleneaniline, 5-isopropylbenzoxazol-2-ylmethyleneaniline, 5-tert-butylbenzoxazol-2-ylmethyleneaniline, 6-
Methoxybenzoxazol-2-ylmethyleneaniline, 5-ethoxybenzoxazol-2-ylmethyleneaniline, 6-chlorobenzoxazol-2-ylmethyleneaniline, 5-brombenzoxazole-2
-Ilmethyleneaniline.

In addition, the methanephosphonic acid ester compound having the general formula ([[) or 4], which is another raw material used in the production method of the present invention, can be prepared by, for example, adding the corresponding halomethyl compound together with an excess amount of phosphite triester in a nitrogen stream. After reacting by heating under reflux, excess phosphorous triester is distilled off, and if necessary, the product is further distilled under reduced pressure. Examples thereof include the following.

Diethyl benzoxazol-2-ylmethanephosphonate-5-methylbenzoxazol-2-ylmethanephosphonate, 5-methylbenzoxazole-2
Dimethyl -ylmethanephosphonate, diethyl 6-methylbenzoxazol-2-ylmethanephosphonate, 5-
Diethyl ethylbenzoxazole-2-ylmethanephosphonate, 5-n-n-propylbenzoxazole-2-ylmethanephosphonate, diethyl 5-isopropylbenzoxazol-2-ylmethanephosphonate, 5-n-n-butylbenzoxazole-2- Diethyl ylmethanephosphonate, 5-Tertiary butylbenzoxazol-2-ylmethanephosphonate, 5
-Methoxybenzoxanzol-2-ylmethanephosphonate diethyl, 6-methoxybenzoxazole-2
di-n-butyl-ylmethanephosphonate, diethyl 5-ethoxybenzoxazol-2-ylmethanephosphonate, dimethyl 5-chlorobenzoxazol-2-ylmethanephosphonate, diphenyl 6-chlorobenzoxazol-2-ylmethanephosphonate , diethyl 5-bromobenzoxazol-2-ylmethanephosphonate, dimethyl benzylphosphonate, diethyl benzylphosphonate, diethyl 4-methoxycarbonylbenzylphosphonate, diethyl 2-cyanobenzylphosphonate, 3-
Dimethyl cyanobenzylphosphonate, dimethyl 4-cyanobenzylphosphonate, diethyl 4-phenylbenzylphosphonate, 4-(4-methoxycarbonylphenyl)
Diethyl phosphonate, 4-(4-cyanophenyl)diethyl phosphonate, 4-(0·σ-diethylphosphotsumethyl)stilbene, 2-cyano-4′-(0·σ-diethylphosphotsumethyl)stilbene, 1· 4-bis(diethylphosphotsumethyl)stilbene, 4,4'-bis(diethylphosphotsumethyl)stilbene, 1,4bis(diethylphosphotsumethyl)benzene, 4,4/-bis(diethylphosphotsumethyl)biphenyl , 1,4-bis(diethylyphosphonomethyl)naphthalene, 2,6-bis(3-chlorophenylphosphonomethyl)naphthalene.

The basic substances used in the method of the present invention are alkali metals, alkaline earth metals, or hydroxides, oxides, alcoholades, hydrides, or amides of these metals, such as sodium hydroxide, hydroxide, Examples include potassium oxide, sodium oxide, sodium methylate, sodium ethylate, sodium hydride, sodium amide, metallic sodium, metallic potassium, and the like.

In addition, reaction solvents include aliphatic and alicyclic alcohols such as methyl alcohol, ethyl alcohol, propyl alcohol, and cyclohexanol; benzene, toluene,
Aromatics such as ethylbenzene, xylenecyclohexane, chlorobenzene, dichlorobenzene, etc. Alicyclic hydrocarbons or their alkylated or halogenated products: Ethers such as diethyl ether, dioxane, and tetrahydrofuran: N-N-dimethylformamide, N-N
- Dimethylcarboxylic acid amides or dialkyl sulfoxides such as dimethylacetamide and dimethylsulfoxide are mentioned, and these may be used alone or in a mixture of two or more types. In order to carry out the method of the present invention, the raw material 1) and the ratio of (n) of one molecule of mint to the raw material 1) or the ratio of one molecule of mint to this (n) or % of
Take a bowl of the molecular proportion and add 3 to about 100 of the total amount.
(weight) times the organic solvent in the presence of 0.8 or more equivalents of the basic substance, preferably 1.0 to 2.0 equivalents,
The reaction is carried out at a temperature of 0°C to 100°C for 10 minutes to 3 hours. When a compound having a carboxyl group is used as a raw material, it is necessary to supply a base in an amount necessary to neutralize the compound in advance.

As the reaction progresses, the reaction product usually precipitates as crystals, which are removed by sieving after the reaction is completed. Moreover, by cooling the reaction-completed liquid or distilling off the organic solvent from the reaction-completed liquid as necessary, the crystals of the product can be precipitated more completely. Next, the details of the method of the present invention will be explained by way of examples.

Example 1 23.6 t of 5-methylbenzoxazol-2-ylmethynyleneaniline was mixed with 1 t of N-N-dimethylformamide.
Heat to 40°C with 00mI1 to dissolve.

To this was added a solution prepared by dissolving 28.27 ml of diethyl 5-methylbenzoxazol-2-ylmethanephosphonate in 50 ml of N-N-dimethylformamide, and then 3.5 V of metallic sodium was dissolved in 50 ml of methanol. Add the alcolade solution and stir at 40°C for 1 hour.
After cooling to room temperature, the crystals were collected by straining, washed with methanol and then water, and dried to give light greenish yellow needle crystals of 1,2-bis-(5-methylbenzoxazol-2-yl)ethylene (4) (melting point 187-188). ℃) 29.0y is obtained. 5-Methylbenzoxazol-2-ylmethyleneaniline used as a raw material for this synthesis was obtained by condensing 5-methylbenzoxazol-2-ylmethanephosulfonate and nitrobenzene in methanol by the action of sodium methylate. Therefore, the melting point is 141~
Obtained as a crystal at 142°C.

In addition, diethyl 5-methylbenzoxazol-2-ylmethanephosphonate 4 is 2-chloromethyl-5-methylbenzoxazole obtained by a condensation reaction of 2-amino-4-methylphenol and chloroacetyl chloride. Obtained by heating and refluxing excess triethyl phosphite in a nitrogen stream, boiling point (0.05 mmHg) 1
It is a liquid with a temperature of 39-140°C and a refractive index (n blue) of 1520. Example 2 In Example 1, 5-methylbenzoxazole-2-
The reaction between ylmethylene aniline and diethyl 5-methylbenzoxazol-2-ylmethanephosphonate was performed using methanol instead of N-N-dimethylformamide used as the solvent, and the reaction temperature was 63°C, and the other conditions were as in Example. The treatment was carried out in the same manner as in 1 above to obtain (b) pale green yellow needle crystals (melting point 187-188°C) 27.
Get 27.

Example 3 5-methylbenzoxazol-2-ylmethylene-4
27.97 ml of '-dimethylaminoaniline is heated and dissolved with 150 mt of tetrahydrofuran.

To this, diethyl 5-methylbenzoxazol-2-ylmethanephosphonate 28,27 was added to tetrahydrofuran 5
After adding the solution dissolved in 0ml, metallic sodium 3,5
An Alcolade solution prepared by dissolving 7 in 50 ml of methanol was added, and the mixture was heated and stirred and refluxed at 62°C for 1 hour. The precipitated crystals were cooled to room temperature, collected by sieve, washed with methanol and then water, and dried to obtain pale greenish yellow needle crystals (melting point 186-187°C) 19.17.

5-Methylbenzoxazol-2-ylmethylene-4'-dimethylaminoaniline used as a raw material for this synthesis was obtained by preparing diethyl 5-methylbenzoxazol-2-ylmethanephosphonate and 4-dimethylaminonitrosobenzene in methanol. , melting point 166-166.5 by condensation under the action of sodium methylate.
Obtained as crystals at °C.

Example 4 One liter of 5-methylbenzoxazol-2-ylmethylene
- Add 150 ml of tetrahydrofuran to 27.97 ml of dimethylaminoaniline, and then add a solution of 28.27 ml of diethyl 5-methylbenzoxazol-2-ylmethanephosphonate dissolved in 50 ml of tetrahydrofuran,
Sodium amide 4 while introducing nitrogen and excluding air
．． Add 37 gradually and stir at room temperature for 2 hours.

The precipitated crystals were separated, washed with methanol and then water, and dried to give pale green yellow needle crystals (melting point 186-1) of (4).
87°C) to obtain 17.87. Example 5 5-methylbenzoxazole-2- in Example 2
Diethyl benzoxazole-2,-ylmethanephosphonate instead of diethyl ylmethanephosphonate 26.8
y was treated in the same manner to obtain light green-yellow needle-like crystals of 1-(benzoxazol-2-yl)-2-(5-methylbenzoxazol-2-yl)ethylene, an asymmetric bisoxazolylethylene compound. (Melting point 172-173℃
)25.27 is obtained.

Benzoxazole-2- used as a raw material for this synthesis
Diethyl ylmethanephosphonate is obtained by the condensation reaction of 2-aminophenol and chloroacetyl chloride.
- Obtained by heating and refluxing chloromethylbenzoxazole with excess triethyl phosphite in a nitrogen stream, boiling point (0.09 mmHg) 148-150'
C, a liquid with a refractive index (n) of 1517.

Examples 6 to 14 Examples of various arylooxazolyl ethylene compounds synthesized by the same method as in Example 1 are shown in Table 1.

Claims (1)

[Claims] 1 General formula (I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(I) (In the formula, R
^1 represents a hydrogen atom, a lower alkyl group, a lower alkoxy group, or a halogen atom, and R^2 represents a hydrogen atom or a dialkylamino group. ) and a Schiff base compound represented by the general formula (I
I) or (III) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(
II) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (III) [Formula (
In II) or (III), X is a phenyl group, biphenylyl group, stilbyl group, which may have a lower alkoxycarbonyl group or cyano group as a substituent, or general formula (IV) ▲ Numerical formula, chemical formula, table, etc. ▼(IV)(
In the formula, R^3 means the same as R^1 in general formula (I), but R^1 and R^3 may be the same or different. , Y represents a phenylene group, a biphenylene group or a naphthylene group, and R
represents a lower alkyl group or a phenyl group. ] There are general formulas (V) or ▲ mathematical formulas, chemical formulas, tables, etc. ▼ (V) ▲ that are characterized by reacting a methanephosphonic acid ester compound represented by the following in an organic solvent in the presence of a basic substance. There are mathematical formulas, chemical formulas, tables, etc.▼(
VI) (In formula (V) or (VI), R^1, X and Y have the same meanings as in general formulas (I), (II) and (III), respectively.) A method for producing a benzoxazolylethylene compound.