DE1179922B - Process for the preparation of ª ‰ -chloroalkyl-chlorocarbonic acid esters - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Boarding school KL: C 07 c

German KL: 12 o-11

Number: 1179 922

File number: B 70799IV b / 12 ο

Filing date: February 20, 1963

Opening day: October 22, 1964

It is known that one / J-chloroalkyl chlorocarbonic acid esters by reacting phosgene with 1,2-alkylene oxides in the liquid phase in the presence of Hydrogen halide (US Pat. No. 2,820,810), pyridine, tertiary bases or Friedel-Crafts catalysts (British Patent 761 874). There is also a known method in which one in the Vapor phase works in the presence of hydrogen halide as a catalyst (US Pat. No. 2820809).

These known processes have the disadvantage that the catalyst is separated off after the reaction has ended must be in order to obtain pure end products. Another disadvantage of these methods is that that the exposure time of the catalyst to the reaction mixture cannot be controlled and therefore the formation of by-products is favored.

It has now been found that /? - chloroalkylchlorocarbonic acid esters from 1,2-alkylene oxides and phosgene in the vapor phase in the presence of catalysts while suppressing the formation of by-products obtained when used as catalysts Chlorides of the noble metals of Group VIII of the Periodic Table, applied to supports are used.

The reaction is carried out at a temperature which is between the boiling points of the reactants and 400 ° C. The reaction is advantageously carried out at a temperature between 160 and 23O ⁰ C. 1,2-alkylene oxides such as ethylene oxide and propylene oxide, with phosgene, which runs in the vapor phase in the absence of catalysts with low turnover is considerably by the inventive catalysts accelerated. The catalysts used are iridium, rhodium or platinum chloride, preferably palladium chloride, which are applied to supports such as aluminum oxide, silica gel, pumice stone or fuller's earth. The amount of chlorides applied to the carrier can be between 0.5 and 25 percent by weight, based on the weight of the carrier. Particularly good results are achieved when the catalyst contains 1.5 to 4.5 percent by weight of chloride. To prepare the catalyst, the support is sprayed with an aqueous metal chloride solution and dried at 100 to 150.degree.

When carrying out the process, the vaporous reactants can be mixed and, expediently heated to the reaction temperature, passed continuously over the catalyst. However, they can also be introduced into the reaction vessel separately, if appropriate preheated. Of the Process for the preparation of / J-chloroalkylchlorocarbonic acid esters

Applicant:

Aniline & Soda Factory in Baden

Aktiengesellschaft, Ludwigshafen / Rhein

Named as inventor:

Dr. Hans Grassner, Heidelberg,

Dr. Fritz Stolp, Limburgerhof (Palatinate)

Catalyst can be fixed or be in swirling motion. It can also be in Presence of an inert gas, e.g. B. nitrogen, to be worked. The amounts of inert gas fluctuate within wide limits. Suitable amounts are e.g. B. 1 to 5 parts of inert gas per part of space Phosgene. The molar ratio of alkylene oxide to phosgene is expediently between 1: 1 and 1: 5; it is advantageously 1: 2. Unreacted alkylene oxide and phosgene can be removed after they have been separated off the reaction mixture, together with new starting material, can be passed over the catalyst again. This increases the yield. In general, normal pressure is used. But you can even under increased pressure, e.g. B. 1 to 5 atü, work. The process can be both continuous as well as discontinuously.

The compounds obtainable by the process are valuable intermediate products for the preparation of pharmaceuticals and pesticides.

The parts mentioned in the following examples are parts by weight. Parts by weight are related to Divisions of space like grams to liters.

example 1

Through a vertical tube 1 m long and 45 mm in diameter, in which 500 parts of a Catalyst made up of 98.5 percent by weight of aluminum oxide and 1.5 percent by weight of palladium chloride consists, are firmly arranged, is every hour at 200 to 220 ° C to the same temperature Preheated mixture of 100 parts by volume of phosgene and 50 parts by volume of ethylene oxide passed. The molar ratio Phosgene to ethylene oxide is 2: 1. After the reaction has started, the heating is turned off of the pipe switched off. At the bottom of the tube

409 708/418

the reaction mixture is converted into liquid and vapor via a staggered separator and cooling system Shares separately. The vaporous components, 65 parts by volume of phosgene and 10 parts by volume of ethylene oxide per hour, are fed back into the reaction. The liquid portions of the reaction product are fractionally distilled.

Liquid in the fractionation of the obtained in the course of 6 hours 1448 parts of the crude product make 1040 parts / S-chloroethyl chlorkohlensäureester having a boiling point from 56 to 60 ⁰ C / 16 Torr and 310 parts of di - (/ J-chloroethyl) -kohlensäureester of boiling point 123 to 127 ° C / 18 Torr. 43 parts remain as the distillation residue.

The degree of conversion of the ethylene oxide is 79%, the yield of ß-chloroethyl chlorocarbonic acid ester 55% of theory.

Example 2

Through the same reaction tube as in Example 1, which is filled with 500 parts of a catalyst consisting of 98 percent by weight of aluminum oxide and 2 percent by weight of rhodium chloride, a mixture of 100 parts by volume of phosgene and 50 parts by volume of ethylene oxide, preheated to the same temperature ^{, is fed every hour at 180 to 200 ° C.} and 50 parts by volume of nitrogen. The molar ratio of phosgene to ethylene oxide is 2: 1. As soon as the reaction has started, the heating of the tube is switched off and the temperature in the catalyst zone is kept at 180 to 200 ^° C. by cooling with air. After 6 hours, the reaction mixture is separated as in Example 1, 75 parts by volume of phosgene and 18 parts by volume of ethylene oxide being returned to the reaction tube every hour. The 1140 parts of liquid crude product obtained are fractionally distilled. This gives 650 parts of 0-chloroethylchloric acid ester with a boiling point of 59 to 61 ° C./20 Torr and 362 parts of di- (/ S-chloroethyl) carbonate with a boiling point of 128 to 130 ° C./20 Torr. 51 parts remain as the distillation residue.

The degree of conversion of the ethylene oxide is 64%, the yield of 3-chloroethyl-chlorocarbonic acid ester 35%, of DHjS-chloräthyty-kohlensäureester 29% the theory.

35

40

45

Example 3

By the same reaction tube as in Example 1, is charged with 500 parts of a group consisting of 98 percent by weight aluminum oxide and 2 weight percent chloroplatinic acid (H ₂ PtCl ₆₎ catalyst, at 200 to 22O ⁰ C hourly a preheated to the same temperature mixture of 120 Parts of phosgene and 50 parts of ethylene oxide. The molar ratio of phosgene to ethylene oxide is 2.4: 1. As soon as the reaction has started, the heating of the pipe is switched off and the temperature in the catalyst zone is regulated by air cooling. After 6 hours, the reaction product is separated as described in Example 1, 89 parts by volume of phosgene and 15 parts by volume of ethylene oxide being returned to the reaction tube every hour. The 1315 parts of liquid crude product obtained are fractionally distilled. This gives 1035 parts / I-chloroalkyl-chlorocarbonic acid ester with a boiling point of 56 to 58 ° C./16 Torr and 186 parts of di- (/ 3-chloroethyl) carbonic acid ester with a boiling point of 126 ° to 128 ° C./16 Torr. 44 parts remain as the distillation residue. The degree of conversion of ethylene oxide is 70%, the yield of / I-chloroethyl chlorocarbonic acid ester is 55% of theory.

Example 4

In the same reaction tube as in Example 1, is charged with 500 parts of a group consisting of 98.5 weight percent AIunüniumoxyd and 1.5 weight percent palladium chloride catalyst, to be at 200 to 22O ⁰ C, 130 parts of propylene oxide which consists of a heated to 8O ⁰ C evaporator comes, reacted with 120 parts by volume of phosgene preheated to the reaction temperature per hour. The molar ratio of phosgene to propylene is 2.4: 1. The reaction mixture is separated as described in Example 1, 84 parts by volume of phosgene and 29 parts of propylene oxide being returned to the reaction vessel every hour. In the fractionation of the incurred in the course of 6 hours the reaction mixture of 1780 parts 1382 parts of (S-chloroisopropyl-chlorkohlensäureester is obtained with a boiling point of 60-63 ⁰ Ql 6 Torr and 181 parts of di- (jS-chloroisopropyl) -kohlensäureester having a boiling point from 133 to 137 ° C / 16 Torr. 63 parts remain as distillation residue.

The degree of conversion of the propylene oxide is 78%, the yield of / I-chloroisopropylchlorocarbonic acid ester 66% of theory.

Claims (2)

Patent claims: 1. A process for the preparation of / 5-chloroalkylchlorocarbonic acid esters by reacting 1,2-alkylene oxides with phosgene in the vapor phase at elevated temperature and in the presence of a catalyst, characterized in that the catalysts used are chlorides of noble metals of Group VIII of the Periodic Table, which are applied to supports, used and at a temperature between the boiling points of the reactants and 400 ⁰ C, preferably at 160 to 230 ° C, works. 2. The method according to claim 1, characterized in that one is in the presence of an inert Gas works. 409 708/418 10.64 ι Bundesdruckerei Berlin