SU527132A3 - The method of obtaining aryl esters of chlorogolic acid or cyclic carbonates - Google Patents

Description

In order to increase the yield and purity of the target product of the proposed method, the reaction products of the compound of formula II with phosgea or phenyl ether of chloric acid are used as a catalyst; as well as compounds of general formula I, in which Rs and RG are a ptrogroup, A is oxygen or cycloalkylene, and the process is carried out with removal of hydrogen chloride from the sphere of reaction. Selection of the target product are well-known techniques.

In order to obtain good yields, psiolzuyut only small amounts of undama catalysts, usually between 0.5 and 5 mol. % The finer the addition of catalysts, the higher the yield of feiyl ether. However, to obtain high reaction rates, you can also use large amounts of catalyst, for example between 10 q and 20 mol. % This leads to lower yields of chloroic acid phenyl ester, since after it is isolated by distillation, the resulting residue consists mainly of the reaction product of chloroholic acid and the amide used, and then it can be used again as a catalyst and obtained at an increased reaction rate high yields. Advantageously, phosphogenation is carried out between 70 and 130 ° C, since in this temperature range, at high reaction rates, only a small formation of by-products, especially diphenyl carbonate, occurs. If the process is carried out in an inert solvent, for example chlorobenzene, or in the case when the hardening point of the reaction mixture is below the point of phenol chlorination, then the reaction is carried out at a temperature of 30 ° C.

With compounds whose melting points are higher than the reaction temperature, it is advisable to carry out the work in solution or suspension, in which case, for example, toluene, xnolol, chlorobenzene or butyl acetate are used as solvents. It is advisable to carry out the work in such a way that the fresh phosgene continuously evaporates from the reaction mixture, entraining the resulting hydrogen chloride. The phosgene leaving the reaction mixture can be separated from hydrogen chloride by condensation.

After removal of excess phosgene by nitrogen extraction and distillation of the solvent, chlorous acid aryl ester or cyclic carbonates is obtained in a yield of more than 90%.

The following examples suggest the proposed method.

Example 1. In a round-bottomed flask equipped with a stirrer, a thermometer, a phosgene supply pipe and a cooler operating at a temperature of from -30 to -40 ° C, a mixture of 94 g of phenol and 3.6 g of M, M-d-methylformamide to 100 ° is heated Phosgene is introduced at a rate of 30 g / hr for 5 hours. The deep-cooling refrigerator is then replaced with a water-cooled fridge so that excess phosgene can volatilize.

Chloroic acid phenyl ester cannot be suspended in a vacuum, i.e. knp. 85 ° / 20 mm; 142 g (91%) are obtained, containing more than 99.7% of the product.

Example 2. In the device described in example 1, heat 94 g of phenol with 1.8 g M, N-dimethylformamide at 120 ° C and pass the phosgene at a speed of 30 g / hour. After a six-hour reaction and subsequent distillation, 147 g (94%) of 99.9% chlorogolic acid phenyl ester are obtained.

Example 3. In a reaction vessel equipped with a stirrer, a thermometer and a phosgene feed pipe, a mixture of 94 g of phenol and 4.4 g of N, N, N, N is tetramethylurea is heated to 120 ° C and phosgene is passed at a rate of 100 g /hour. After 5 hours, the supply of phosgene is completed and the reaction mixture is not stirred; 144 g (92%) of 99% chlorogolic acid phenyl ester are obtained.

Example 4. The reaction was carried out as described in Example 3, but a high pressure vessel with a safety valve, which regulates the hydrogen chloride and excess phosgate, is used as the reaction vessel so that the pressure in the reaction vessel is 1 atm. After the termination of phosgeneration, the pressure is reduced, and chlorofolic acid phenyl ester is distilled off from the reaction mixture. Out; and purity correspond to the product found in Example 3.

Example 5. a. In a bottle described in nimer 1, a mixture of 94 g of feiol n 15 g S, K-dimethylformamndand at 80 ° C is heated for 3 hours with 150 g of phosgene. After completion of the reaction, the product obtained is distilled, and PO g of chlorogolic acid phenyl ester is obtained. After non-distillation, a strongly hygroscopic residue remains in the flask, which serves as a catalyst in the following experiments.

b. The residue obtained in Example 5, a, after distillation, is mixed with 94 g of phenol and, similarly to Example 5, and is reacted with phosgene. After processing, 149 g (95%) of chloroic acid ester are obtained. The residue and after distillation can again be used as a catalyst for phosgenation.

Example 6 1.8 g of N, N-dimethylformamide is dissolved in 50 ml of benzene and 5 g of phosgene are introduced at room temperature. At the same time, the dimethylformamide chloride disappears as a colorless precipitate. Then, benzene is distilled off under vacuum, and the remaining residue is used instead of dimethylformamide as a catalyst for 5 to react phenol with

phosgene, analogously to example 2. The result is phenyl EFPR almost with the same yield and purity as in example 2.

Example 7. 1.8 g of N, N - dimethylformamide is dissolved in 50 ml of benzene, 3.0 g of chlorogolic acid phenyl ester is added and the mixture is heated with stirring to 50 ° C. Gaseous formation occurs and a slightly yellow precipitate is formed. After the end of gassing, the solvent was distilled off in vacuo at a bath temperature of 50 ° C and the remaining residue was used instead of dimethylformamide, as described in Example 2. The yield and purity of the chloroic acid phenyl ester are as described in Example 2.

Examples 8-12. As described in example 3, every 94 g of phenol with the addition of the amide of the acid specified in table. 1, is reacted with phosgene. After distillation

Table I

Chloroic acid phenyl ester is obtained with the indicated yield and purity in excess of 99%.

Example 13. In a round-bottomed flask with a stirrer, a thermometer, a phosgene supply pipe and a reflux condenser, EIT. IM at -30 ° C, the mixture consisting of 150 g of o-egor-butylphenol and 4 g is heated to 100 ° C N, N, N, N is tetramethylurea and phosgene is supplied at such a rate that the reverse note of phosgene in a deep-cooled refrigerator is not too strong and the reaction temperature is not ionized. After a nichas reaction and phosgene consumption of about 190 g, the deep-cooling reflux condenser is replaced by a water-cooled condenser so that most of the excess phosgene can be distilled off from the reaction mixture. The phosgene residue is blown out with dry nitrogen. The result is o-sec-butylphenyl ester of chlorogolic acid (97%), practically free from the starting material.

Examples 14-31. Analogously to the method described in Example 13, the phenols and naphthols listed in Table 2 are reacted with phosgene. 2 to obtain the corresponding chloroic acid esters. The reaction with solid starting compounds is carried out in the indicated solvent.

table 2

 DMF-M, K-dimethylformamide.

 TMM-N, N, N, N-tetrammethylchemone.

Example 32. A mixture of 55 g of pyrocatechin, 55 g of chlorobenzene and 2 g of tetramethylurea are heated to 100 ° C. At this temperature

The phosgene is introduced at such a rate that condensate slowly accumulates in a refrigerated cooling box down to -20 ° C. Nagre