DE1108220B - Process for the preparation of compounds of the 1,3-divinylbenzene series - Google Patents

Description

Process for the preparation of compounds of the 1,3-divinylbenzene series Compounds of the 1,3-divinylbenzene series have been relatively difficult to access up to now. You can e.g. B. be produced by means of processes that adhere to the principle of Follow Perkin's synthesis, or by reacting a suitable Grignard compound with an isophthalaldehyde and dehydration of the resulting diols. Both Processes only lead to unsatisfactory yields and impure compounds. About that in addition, the Grignard synthesis has the disadvantage that starting materials with functional Groups that react with the Grignard compounds themselves are not implemented can.

It has now been found that compounds of the 1,3-divinylbenzene series are obtained in one process stage with good yields and in excellent purity if bis-phosphonic esters of the general formula are used in which R1 and R2 are identical or different aliphatic, cycloaliphatic, aromatic or araliphatic radicals or together with the radical Members of a heterocyclic ring can be in which R3, R4, R5, R6, R7 and R8 denote hydrogen or identical or different aliphatic, cycloaliphatic, araliphatic or aromatic radicals, optionally esterified carboxyl groups, carbonamide or cyano groups, in which R4, R5 and R6 can also be members of a fused-on cycloaliphatic or aromatic ring and in which R3, R4, R5 and R6, in addition to the meaning given above, also halogen atoms, amino, nitro, free or esterified sulfonic acid groups, and free, etherified or esterified hydroxyl and mercapto groups mean, reacts with an oxo compound in the presence of a proton acceptor.

The almost without exception unknown compounds of general formula 1, which are used as starting materials for the process according to the invention, can be obtained in a manner known per se, e.g. B. in a simple way by reacting a compound of the general formula in which R 1, R4, R5, R6, R7 and Rs have the meaning given in formula I and Y denotes a halogen atom or the tosyloxy radical, with a phosphorous acid ester of the general formula in which R1, R2 and also R9 have the meaning given above for R1 and R2. Of the phosphorous acid esters, those derived from lower aliphatic alcohols are preferred for technical reasons.

For the preparation of the bis-phosphonic esters of the general formula 1 suitable compounds of the general formula II are, for example, 1,3-dichloromethylbenzene, 1, 3-dichloromethyl-4, 6-dimethylbenzene, 1, 3-dichloromethyl-4, 6-dimethoxybenzene, 1,3-dichloromethyl-4, 6-dichlorobenzene, 1,3-dichloromethyl-4-nitrobenzene, 1 , 3-dichloromethyl-4-chlorobenzene, 1,3-dichloromethyl-2-benzenesulfonic acid, 1,3-dibromomethylbenzene, 1,3-dichloromethyl naphthalene.

For the preparation of the starting compounds of the general formula I no protection is sought.

As oxo compounds are all compounds that one or also contain several aldehyde or keto groups in the molecule. As examples are called: formaldehyde, d, acetaldehyde, acrolein, crotonaldehyde, acetone, methoxyacetone, Glyoxal, ß-formylorotonic acid ester, citral, methylheptenone, benzaldehyde, acetophenone, Benzophenone, furfurol, phenylacetaldehyde, p-nitro-benzaldehyde, piperonal, 2,6-dichlorobenzaldehyde, p-dimethylamino-benzaldehyde, p-acetoxyamino-benzaldehyde, 2,6-dimethoxybenzaldehyde, 4-methyl-2,6-dimethoxy-benzaldehyde, p-isopropyl-benzaldehyde, 2,4-dimethoxy-benzaldehyde, 4-methoxy-benzaldehyde, p-phenoxy-benzaldehyde, 3-methyl-4-methoxy-benzaldehyde, 2,4,6-trimethyl-benzaldehyde, 3, 4-methylenedioxy-2-methoxybenzaldehyde, N- (ß-diethylaminoethyl) -p-aminobenzaldehyde, 4 (ß-oxethyl) -oxy-benzaldehyde, p-aminobenzaldehyde, p-cyano-benzaldehyde, p-carbethoxybenzaldehyde, 2,5-endoethylene-d 3-tetrahydro-benzaldehyde, 4-hexahydro-pyranyloxy-benzaldehyde, 4-tetrahydrofuranyl-oxy-benzaldehyde, cinnamaldehyde, phenylpentadienal, terephthalaldehyde, 2-chloro-4-formylbenzenesulfonic acid, 2-chloro-4-formylbenzenesulfonic acid amide, thymolaldehyde, nc-naphthaldehyde, tetrahydronaphthalene-l-aldehyde, anthracene-9-aldehyde, phenanthrene-9-aldehyde, Ferrocene aldehyde, acridine-9-aldehyde, fluorene-2-aldehyde, acenaphthene-5-aldehyde, 3,4-benzpyran-5-aldehyde, 9-chloro-anthracene-10-aldehyde, 2,4-dimethylpyrrole-5-aldehyde, 2-methyl-3-carbethoxy-pyrrole-5-aldehyde, 2-carbethoxyindole-3-aldehyde, indole-3-aldehyde, naphthostyrylaldehyde, thiophene-2-aldehyde, Pyrene-3-aldehyde, N-methyl-carbazole-3-aldehyde, anthraquinone-2-aldehyde, anthrapyrimidine aldehyde, Antipyrine aldehyde, 2-mercapto-4-methyl-glyoxaline-5-aldehyde, 2-formylmethylene-3,4-dimethyl-thiazoline, Diphenyl-4-aldehyde, diphenylene oxide-1-aldehyde, carbazole-2-aldehyde, thionaphthen-2-aldehyde, Tolylaldehyde, 1,4-diphenylnaphthalene-2-aldehyde, pyridine-2-aldehyde, pyridine-4aldehyde, Quinoline-2-aldehyde, benzthiazol-2-aldehyde, 3-methyl-quinoxaline-2-aldehyde, 4-nitro-diphenyl-4'-aldehyde, Bz.-l-benzanthrone aldehyde, 5-methyl-isoxazole-3-aldehyde, 3-tetrahydrofuryl-oxindole-2-aldehyde, 3-tetrahydrofuranyloxy-thionaphthen-2-aldehyde, 4-methoxy-1-naphthaldehyde and methyl terephthalaldehyde ester. A particularly smooth implementation and particularly valuable products are achieved if such oxo compounds are used whose carbonyl group has a direct CC linkage connected to an aromatic ring A.

Primarily basic compounds are suitable as proton acceptors, such as alkali or alkaline earth metal hydroxides, alkali metal or alkaline earth metal alcoholates, alkali or Alkaline earth amides, strongly basic amines and anion exchange resins in the hydroxyl form.

The process is advantageously carried out in solvents which are below are indifferent to the implementation conditions. Examples are hydrocarbons, such as hexane, octane, isooctane, cyclohexane, toluene, xylene and their chlorination products, such as tri- and tetrachlorethylene, chlorobenzene and dichlorobenzene, alcohols such as methanol, Ethanol, Isopropanol, butanols, glycols, hexanols, cyclohexanol and cyclooctanol, also ethers, such as diisopropyl ether, tetrahydrofuran, dimethyltetrahydrofuran, dioxane and ethylene glycol dimethyl ether called. Strongly polar organic ones are particularly suitable Solvents such as formamide, dimethylformamide, acetonitrile, N-methylpyrrolidone and Dimethyl sulfoxide. The reaction runs particularly easily in these solvents with excellent yields. The process can also be carried out in aqueous solution run some cases.

The reaction temperature depends on the type of components to be converted, in particular of the nature of the organic compounds containing carbonyl groups and the proton acceptor; it is usually between about 0 and +100 "C.

It is advisable to use the most favorable reaction temperature in each case to be determined by a preliminary test.

The claimed method can be carried out, for example, that the organic compound containing carbonyl groups, the compound of general formula I and advantageously presents an inert solvent and in the mixture with stirring the proton acceptor, optionally dissolved or suspended, enters. It is also possible to initially convert the proton acceptor only to the bisphosphonic acid ester of the general formula I and then the organic containing carbonyl groups Add connection. As a rule, the reactants are used in stoichiometric amounts Amounts of, however, in some cases is an excess of one or the other Reaction partner an advantage. The implementation is generally under strong Heat development, so that you may have to cool. The reaction mixture can be worked up in a known manner, e.g. B. by adding water or Methanol and optionally an acid such as acetic acid or sulfuric acid to the Conversion mixture, and separation of the precipitated products.

The 1,3-Bisstyrylbenzenes obtainable by the new process show often fluorescence and are suitable as light stabilizers for white tannins, as Stabilizers for polyamides and as intermediates for pharmaceuticals, Pesticides and dyes. Their use is particularly advantageous as optical brighteners for plastics because they are used to achieve an optimal effect must be used in significantly smaller quantities than known products.

In the known method, from Triarylphosphoniumyliden and z. B. aldehydes or ketones organic compounds with the formation of a new carbon-carbon double bond build up, triarylphosphine oxide is formed, which is usually difficult to remove from the reaction product can be separated. The salts of phosphoric acid diesters formed in the process according to the invention on the other hand, can easily be removed with water. In addition, triarylphosphine oxides are By-products that are not usable as such and their conversion into usable Products are not worth it. The phosphoric acid esters resulting from the process of this invention are, however, technically usable as such and after simple further processing Products.

The Triarylphosphoniumylide can by water in the presence of alkali, that for their production from the corresponding phosphonium salts is required to be degraded to phosphine oxides and hydrocarbons, so that as far as possible to work in an anhydrous reaction mixture. This is at the method according to the invention is not required.

The parts mentioned in the following examples are parts by weight; they relate to the specified parts of the volume as grams to cubic centimeters below Normal conditions.

Example 1 38 parts of m-xylylene tetraethyl diphosphonate are added in 150 Parts by volume of dimethylformamide dissolved. 25 parts of benzaldehyde are added to the solution and then, with vigorous stirring, 40 parts of 30% methanolic sodium methylate solution. In a strongly exothermic reaction, 1,3-distyrylbenzene is formed, which in colorless, red-violet fluorescent cuboids fails.

After cooling, the reaction mixture is mixed with 100 parts by volume of methanol added and adjusted to the p-value 7 with glacial acetic acid. The precipitate is filtered off with suction and washed with methanol. After redissolving from xylene, 17 parts of 1,3-distyrylbenzene are obtained from melting point 169 to 171 "C.

The in the preceding, the method according to the invention illustrative Embodiment mentioned starting compound m-xylylene tetraethyldiphosphonate is obtained in the following way: To 350 parts of triethyl phosphite is added at 140 to 1500 C gradually the solution of 175 parts of m-xylylene dichloride in 500 parts by volume Xylene. The reaction mixture is refluxed for 12 hours. The emerging Ethyl chloride distills off. The solvent is then distilled under normal pressure and then removed volatile by-products under reduced pressure Pressure. 360 parts of m-xylylene tetraethyldiphosphonate fall as the residue thick, pale yellow oil that is processed as a raw product.

Example 2 95 parts of m-xylylene tetraethyl diphosphonate and 90 parts p-Nitrobenzaldehyde is dissolved in 200 parts by volume of dimethylformamide. While stirring 100 parts of 300 strength methanolic sodium methylate solution are added dropwise to the solution. The contents of the vessel turn brown when heated to a considerable extent. After a few minutes crystals fall out.

The reaction mixture is stirred for 1 hour, then with 150 parts by volume Diluted methanol and adjusted to pH 7 with glacial acetic acid. The yellow orange ones Crystals are filtered off with suction, washed with methanol and recrystallized from dimethylformamide. In this way, 36 parts of 1,3-bis- (p-nitrostyryl) -benzene with a melting point are obtained 265 to 267 ° C.

Example 3 95 parts of m-xylylene tetraethyl diphosphonate and 90 parts m-nitrobenzaldehyde is dissolved in 200 parts by volume of dimethylformamide. While stirring 100 parts of 30% methanolic sodium methylate solution are added dropwise. Under The contents of the vessel turn brown when heated. After a few minutes, crystals will fall the end. The reaction mixture is stirred for 1 hour, then with 150 parts by volume of methanol diluted and with glacial acetic acid to the pn value 7 set. The yellow needles will suctioned off, washed with methanol and recrystallized from dimethylformamide. on 33 parts of 1,3-bis- (m-nitrostyryl) -benzene having a melting point are obtained in this way 189 to 191 "C.

Example 4 114 parts of m-xylylene tetraethyl diphosphonate and 100 parts p-Dimethylaminobenzaldehyde is dissolved in 200 parts by volume of N-methylpyrrolidone. At 60 ° C., 120 parts of 30 ° / o strength methanolic solution are added to the solution with vigorous stirring Sodium methylate solution was added dropwise. The solution takes on an orange-yellow color at. Little by little, pale yellow crystals fall out. The reaction mixture is Maintained at 65 to 70 ° C. for 5 hours, then mixed with 200 parts by volume of methanol. The precipitate is filtered off with suction, washed and redissolved from dimethylformamide. So 42 parts of 1,3-bis (p-dimethylaminostyryl) benzene are obtained as pale yellow needles from melting point 229 to 231 ° C.

Example 5 95 parts of m-xylylene tetraethyl diphosphonate and 90 parts Piperonal are dissolved in 200 parts by volume of N-methylpyrrolidone. While stirring vigorously 100 parts of 30% methanolic sodium methylate solution quickly become the solution added dropwise. Colorless crystals precipitate in a strongly exothermic reaction. The mixture is stirred for 1 hour, then diluted with 200 parts by volume of methanol and vinegar with ice cream set to the p, value 7. The precipitated reaction product is filtered off with suction and redissolved from toluene. 41 parts of 1,3-bis (3 ', 4'-dioxymethylene styryl) benzene are thus obtained as bright white crystals with a melting point of 189 to 191 "C. The solutions in organic Solvents fluoresce red-violet.

Example 6 38 parts of m-xylylene tetraethyl diphosphonate and 35 parts 1-Naphthaldehyde is dissolved in 100 parts by volume of dimethyl sulfoxide. Under animated 40 parts of 30% methanolic sodium methylate solution are rapidly added to this solution added dropwise. In a strongly exothermic reaction, pale yellow crystals precipitate. The mixture the mixture is stirred for a further 1 hour after the sodium methylate has been added, then with 100 parts by volume Diluted methanol and adjusted to p-value 7 with glacial acetic acid. The unusual one The reaction product is filtered off with suction and redissolved from xylene. This gives 28 parts of 1,3-bis (naphthostyryl) benzene as light yellow crystals with a melting point of 125 to 126 ° C.

Example 7 38 parts of m-xylylene tetraethyl diphosphonate and 30 parts Cinnamaldehyde is dissolved in 180 parts by volume of dimethylformamide. While stirring vigorously 40 parts of 30 ° / Oige methanolic sodium methylate solution are added to this solution quickly added dropwise. Yellowish crystals precipitate in a strongly exothermic reaction. The mixture is stirred for 1 hour, then diluted with 100 parts by volume of methanol and with Glacial acetic acid neutralized. The precipitated reaction product is filtered off with suction, with methanol washed and recrystallized from dimethylformamide. So you get 23 Parts of 1,3-bis- (eX-phenylbutadienyl) -benzene as light yellow flakes with melting point 197 to 1990 C, which fluoresce blue-violet in solution.

Claims (3)

PATENT CLAIMS: 1. Process for the preparation of compounds of the 1,3-divinylbenzene series, characterized in that bis-phosphonic esters of the general formula in which R1 and R2 are identical or different aliphatic, cycloaliphatic or araliphatic radicals or together with I can be -OPO members of a heterocyclic ring, in which R ,, R4, R5, R6, R7 and R8 are hydrogen, identical or different aliphatic, Cycloaliphatic, araliphatic or aromatic radicals, optionally esterified carboxyl groups, carbonamide or cyano groups denote in which R4, R5 and R6 can also be members of a fused-on cycloaliphatic or aromatic ring and in which R2, R4, R5 and R6 go beyond the meaning given above can also mean halogen atoms, amino, nitro, free or esterified sulfonic acid, free, etherified or esterified hydroxyl and mercapto groups, with an oxo compound in the presence of a proton acceptor and preferably an inert organic solvent. 2. The method according to claim 1, characterized in that as Proton acceptor an alkali or alkaline earth hydroxide, an alkali or alkaline earth alcoholate or an alkali or alkaline earth amide is used. 3. The method according to claim 1, characterized in that the Reaction in a polar organic solvent such as formamide, acetonitrile, Dimethylformamide, N-methylpyrrolidone or dimethyl sulfoxide, executes. Publications considered: Bulletin de la Societe Chimique de France, 1958, pp. 1021 to 1037.