SU883000A1 - Method of preparing 4-alkoxy-2-oxyphenones - Google Patents

Description

The invention relates to an improved process for the preparation of 4-alkoxy-2-oxyphenones, which can be used as complexing agents for non-ferrous metals, as light stabilizers for polymers, and as intermediates in the synthesis of 4-alkoxy-2-oxyphenone oxime extractors for the extraction of copper. A known method of producing asymmetric ethers of primary and secondary alcohols by reacting them with chloride alkyls in the presence of a 5-fold excess of an aqueous or alcoholic solution of sodium hydroxide and a phase transfer catalyst is tetrabutylammonium bisulfate; in the case of primary alcohols, a yield of 92–97% is obtained and the process time is 3–4 hours} in the case of secondary alcohols, a greater amount of time i is required. However, this method is not applied for the preparation of aliphatic-aromatic efi is also known to prepare 4-alkoxy-2-oksifenonov, comprising the alkylation of resorcinol methyl alkyls in an alcoholic solution of alkali, reacting the resulting m-dialkoksibonzolov with acid chlorides of aliphatic and aromatic carboxylic acids under conditions of Friedel - Crafts with the subsequent dealkylation of the obtained product with glyceral acid. The yield of products in this case is 60-70%. The disadvantages of this method are the multistage process, the insufficiently high yield of products, the use of acutely scarce and expensive methyl bromides as alkylating agents, and the high consumption of aluminum chloride. The closest technical solution to the invention is a method for producing 4-alkoxy-2-oxyphenones by treating the corresponding 2,4-dioxybenzophenones with methyl bromides in an aqueous alcohol solution of sodium hydroxide, the process is carried out with prolonged heating at 75-115 ° C, mainly at boiling 18 -23 h, the yield of the target products is 30-40% 3, However, the low yield of the final products, the use of scarce and double-stranded alkyl bromides, a longer process time, as well as an increased risk of fire during the production process. The process associated with the use of flammable solvents (ethyl alcohol) limit the use of this method.

The purpose of the invention is to increase the yield of the target products, to intensify and simplify the process of obtaining 41 alkoxy-2-oxyphenones of the general formula.

RO

where R is alkyl With 4 - C-;

R is hydrogen, phenyl or alkyl.

This goal is achieved by the fact that the process is carried out by the interaction of the corresponding 2,4-dioxyfecones with halide alkyls in the presence of alkali at -75-10.0 ° C and phase transfer catalysts - crown ethers.

A distinctive feature of this method is the process of reacting 2, 4-dioxyphene-ions with halide alkyls in the presence of phase transfer-cyclic polyether catalysts (crown ethers

It is advisable to carry out the process with a 5–20-fold excess of a 50% aqueous solution of potassium hydroxide in the presence of 0.5–5.0 mol% of crown ethers, preferably dicyclohexyl-18 crowns-6, in the process usually used as alkyl halides chloride alkyls ..

The process is carried out as follows.

A mixture of 2,4-dioxybenzophenone, alkyl chloride, crown ether and a 50% aqueous solution of potassium hydroxide is heated under vigorous stirring for 10-20 hours. After separation, the organic layer is dispersed in vacuo.

The process is carried out at 75-115 ° C, depending on the boiling point of the mixture. The reaction time is determined by the process temperature. If when using butyl chloride the reaction time is 20 hours, then when using chloride alkyls with the number of carbon atoms C5 and higher, the reaction time does not exceed 10 hours,

For the process, a 5–20-fold excess of a 50% aqueous solution of potassium hydroxide is used. When using a smaller excess of alkali, the reaction time is increased, the yield of the final products decreases. The use of more than 20-fold excess alkali leads to an unreasonable increase in the reaction volume,

As the catalyst for the process, various crown ethers can be used, for example, dicyclohexyl-18-4kC aun-b, dibenzo-18-crown-6, 18-crown-6, as well as 15-crown-5,24-crown -8, dicyclhexyl-24-crown-8, di (dodecylbenzo) -18-crown-b,

The best results were obtained when using dicyclohexyl-18-crown-6. The catalyst for the process is used in the amount of 0.5 to 5 mol%. Below 0.5 mol%, the catalytic effect almost does not show up; an increase in the amount of catalyst above 5 mol% has no significant effect on the process.

Total conversion is observed by the number of ionic chlorine in the aqueous phase, as well as by spectrophotometric. determining the content of reaction products in the organic phase.

Example 1 (comparative according to G31), Preparation of 4-butoxy-2-oxy5 benzophenone (without catalyst).

A mixture of 10.7 g (0.05 mol) of 1,4-dioxybenzophenone, 23.1 g (0.25 mol) of butyl chloride and 80 ml of a 50% aqueous solution of potassium hydroxide is heated at 75 ° C for vigorous stirring. 55 hours. After cooling, 10b ml of water is added to completely dissolve the precipitate, the organic layer is separated, washed with 10% hot alkali solution, 5% hydrochloric acid solution and water. The excess butyl chloride is distilled off, the residue is distilled in vacuo.

Obtained 3.1 g of the finished product,

JQ yield 23 theoretically,%, t, kip, 200 203 C / 3 mm, IR spectrum (droplets between glasses) 1630 cm} UV spectrum (CH-jOH), n-.J junction, 1 rndX 25 nm, 1dg 4.19,

. Example 2 (comparative according to G1), Preparation of 4-butoxy-2-hydroxybenzophenone using TBABS as catalyst,

A mixture of 10.7 g (0.05 mol) of 2,4-dioxybenzophenone, 23.1 g (0.25 mol)

0 butyl chloride, 0.85 g (0.0025 mol) of TBABS and 80 ml of a 50% aqueous solution of potassium hydroxide are heated at 75 ° C for 30 hours with vigorous stirring. After cooling, 80 Mp of water are added to completely dissolve the precipitate. . The organic layer is washed with a 10% hot alkali solution, 5% n / 1 hydrochloric acid solution and water. The excess chlorine is distilled off. butyl, the residue is distilled in vacuo.

Obtain 7.3 g of 4-butoxy-2-hydroxybenzophenone, yield 54.1 theoretical,%, t, kip, 200-203 ° C / 3 gm, IR spectrum (drops between the panes) (1630,

 UV spectrum (CHjOH), n J transition,. 325 nm, Ig e 4.19,

Example 3, a Mixture of 10.7 g (0.05 mol) of 2,4-dioxybenzophenone, 23, 1 g (0.25 mol) of butyl chloride,

0 0.93 g (0.0025 mol) of dicyclohexyl18-crown-6 (DCG18C6) and BO ml of a 50% aqueous solution of potassium hydroxide are heated at 75 ° C for 20 hours with vigorous stirring. After 5 cooling, 80 ml of water are added dl

complete dissolution of the precipitate. The organic layer is washed with a 10% hot alkali solution, 5% hydrochloric acid solution and water. The excess butyl chloride is distilled off, the residue is distilled in vacuo.

9.9 g of 4-butoxy-2-hydroxybenzophenone are obtained, yield 73.3 theoretical%.

The aqueous layer was separated, the HC1 concentration was acidified to pH 2, the precipitated white precipitate was filtered off, filtered through 50 ml of water, and dried in vacuo. 2.3 g of 2,4-dioxybenzophenone was obtained, which is 21.5% based on the starting 2,4dioxybenzophenone loaded.

Taking into account unreacted 2,4-dioxybenzophenone, the yield of 4-butoxy-2-hydroxybenzophenone is 94.8%.

Similarly, when using dibenzo18-crown-6 as a catalyst, 4-butoxy-2-hydroxybenzophenone is obtained with a yield of 65 theoretical% s; when used as an 18-crown-6 catalyst, a 4-butoxy-2-hydroxybenzophenone is obtained with a yield of 60 theoretical .%.

Example 4. A mixture of 21.4 g (0.1 mol) of 2,4-dioxybenzophenone, 74.3 g (0.5 mol) of octyl chloride, 1.86 g (0.005 mol) of DCPPC and 160 ml of a 50% aqueous solution potassium hydroxide with vigorous stirring is heated at 115 ° C for 10 hours. After cooling, 200 ml of water are added to dissolve the precipitate completely, the organic layer is separated, washed with a 10% hot alkali solution, 5% hydrochloric acid solution and water An excess of octyl chloride is distilled off, the residue is distilled in a vacuum.

24.5 g of product are obtained, yield

75.1% theoretical, bp 210-213 ° C /

1 MTi, IR spectrum (droplets between glasses) -VC-Q 1626 cm-, UV spectrum (CHjOH) transition, V mco; 320 nm, Igg 4.00.

In a similar way, the interaction of octyl chloride with 2,4-dioxybenzaldehyde gives 4-octoxy-2-hydroxybenzaldehyde, yield

69.2 theoretical%, bp 127-129c /

1 mm, IR spectrum (droplets between glasses) 1680 by the interaction of octyl chloride with 2,4-dioxyacetophenone 4-octoxy-2-oxyacetophenone was obtained, yield 77.1 theoretical,%, kip. 145-147 ° C / 1 mm, IR spectrum (droplet between glasses) 1665; 4-octoxy-2-oxycaprinophenone was obtained in the interaction of octyl chloride with 2,4-dioxycaphenofenone, 71.8%. theoretical%, t.kip, 222-224 ° C / 1 mm, IR spectrum (drop between glasses) 1645, UV spectrum (SNdON), p 37 transition,% meii 316 nm, 1дЕ4,13 (4,4-dodecyloxy-2-oxybenzophenr) was obtained by the interaction of 2,4-dioxybenzophenone with codecyl chloride, yield 61.3 theoretical.

%, TP.- 230-245C / 1 mm, IR spectrum (droplets between glasses) i / ceo 1629 cm-, UV spectrum (SNDN), item 7 transition, Xn, 325 nm, 1d 4, 20.

Example 5. Obtaining 4-hexoxy-2-hydroxybenzophenone. A mixture of 21.4 g (0.1 mol) of 2,4-dioxybenz6phenone} 60.3 g (0.5 mol) of hexyl chloride 1.86 g (0.005 mol) of dicyclohexyl18-crown-6 (DCG18K6) and 160 ml of 50% water solution of caustic potash

0 (20-fold excess KOH) with vigorous stirring is heated at 115 s for 10 h. After cooling, add 200 ml of water to completely dissolve the precipitate, organic

5, the layer is separated, washed with a 10% hot alkali solution, 5% hydrochloric acid solution and water. The excess hexyl chloride is distilled off, the residue is distilled in vacuo.

0

22.4 g of product are obtained, yield

75.2% theoretical, bp 196-193 ° C /

1 mm, IR spectrum (droplets between glasses) 1626, (this example shows the effect of alkali and crown ether on the yield of 4-hexoxy-25 hydroxybenzophenol),

When carrying out the reaction as described in example 4, using 40 ml of a 50% aqueous solution of potassium hydroxide (5-fold excess of KOH), 4-hexoxy-2-hydroxybenzophenone is obtained with a yield of 73.4 theoretical%;

when using a 4-fold excess of potassium hydroxide, 4-hexoxy-2-hydroxybenzophenone is obtained with a yield of 62.3 theoretical 5%;

using a 25-fold excess of KOH, 4-hexoxy-2-hydroxybenzophenone is obtained with a yield of 75.2 theoretical%.

Similarly, as described

0 in example 4, using 2.23 g of DCCA18C6 (6 mol.%), 4-hexoxy-2-hydroxybenzophenone is obtained with the yield

75.3% theoretical;

when using 1 mol.% DGGC18K6 get 4-hexoxy-2-hydroxybenzophenone

5 with a yield of 70.9 theoretical%;

with the use of 0.5 mol.% DCH18C6, 4-hexoxy-2-hydroxybenzophenone is obtained with a yield of 53.4 theoretical%.

Example 6. Getting 40 alk () hydroxy-2-hydroxybenzophenone. A mixture of 21.4 g (0.1 mol) of 2,4-dioxybenzophenone, 74.3 g (0.5 mol) of alkyl chloride (), 1.86 g (0.005 mol) of DsG18K6 and 160 ml of a 50% 5% aqueous solution potassium hydroxide is heated at 115 ° C for 10 hours with vigorous stirring. After cooling, 200 ml of water are added to dissolve the precipitate completely, the organic layer is separated, dried with D0% hot alkali solution, 5% hydrochloric acid solution. hydrochloric acid and water. Excess alkyl chloride () is distilled off, the residue is distilled

5 in a vacuum.

Get 23.9 g of the finished product, the output of 73.3 theoretical.%, BP. 204-225С / 1 mm, IR spectrum (droplet between glasses) 1626.

For the other values in the range, the reaction proceeds in a similar way.

Claims (3)

1. A method for preparing 4-alkoxy-2-oxyfenrnes of the general formula RO- / where D is alkyl C4-C-fi, R-hydrogen, phenyl, alkyl, by the interaction of the corresponding 2,4-dioxyphenones with alkyl halides in the presence of alkali at temperature. re VS-llS C, about tl. and h and y with the fact that, in order to increase the yield of target products, to intensify and simplify the process, the latter is carried out in the presence of phase transfer catalysts - crown ethers. 2. Spore under item 1, characterized in that the process is carried out with a 5-20-fold excess of a 50% aqueous solution of caustic mixture in the presence of 0.5-5.0 mol.% Dicyclohexyl-18-crown-b . 3. The method according to claim 1, which is also distinguished by the fact that chloride alkyls are used as alkyl halides in the process. Sources of information taken into account in the examination 1.N.N. Freedman, R.A.Dubpis, An improved William-Son Ether Synthesis using phase transfer catalysis. - Tetr. Lett., 1, 1975, No. 38, p. 3251-3254. 2. USSR author's certificate number 215930, cl. C 07 C 49/82, 1965. 3. Larina N.A., Matveeva E.N., Smirnova B.C. Synthesis of some 2oxy-4-alkoxybenzophenones. - JOH, 30, I960, p. 2377 (prototype).