SU489304A3 - Method for producing monohaloacetic acid halides - Google Patents

Description

g-butyrolactone is used, and chlorine or bromine is used as halogen.

In addition, j9 -propiolactone, 7-valerolactone, -caprolactone, ° C -butyl-T-butyrolactone, J-chloro-G butyrolactone, -phenyl-G-butyrolactone and .i1 - 1- tolyl-T-butyrolactone.

Predominantly ketene is used predominantly in the process.

chlorine is used in the initial halo.

When carrying out the proposed method, monohaloacetic acid halohydride is obtained in a yield of 80-96%, and the purity of the target product is 98-1OO%.

In addition, a more complete regeneration of the organic solvent used in the process is achieved.

In the process, ketene and ha; a loid is introduced into a reaction vessel in which the corresponding lactone is placed. As a result of the interaction, monohaloacetic acid halides are formed. The latter are separated from the reaction mixture by conventional methods, such as distillation, preferably under reduced conditions. pressure. The method can be carried out both continuously and intermittently.

The process is usually carried out at a temperature of minus 50 - plus 15 ° C under a pressure of 1OO-76 ° mm Hg. The reaction between halogen and ketene occurs with the formation of pure halo-hydrides of monohaloacetic acid. Regardless of the molar ratio of the reactants. However, it is advisable to keep the molar ratio of halogen to ketene equal to 0.8-2: 1, while the optimal results are obtained when the molar ratio of halogen and ketene is 13: 1.

It is advisable to maintain the ratio of lactone to the reaction mixture at 0.05 - O, 99 :: 1-. When carrying out the perodonic process, the weight ratio of solvent decreases as the formation of the desired product, which is mixed with the lactone, is formed; When implementing the continuous process, the solvent weight ratio may be kept constant or BapbiqxtBaTbCH to the desired level.

in the examples given, all ratios are expressed in parts by weight.

Example. 191 parts. T-butyrolactone is loaded into a suitable reaction vessel equipped with

mixing, Tjiy6KoA for gas outlet, devices for reggstrapia temperature two distributors for the feed gas, located below the level 5 of the lactone. With continuous stirring at atmospheric pressure and maintaining the temperature of the reaction medium at about 24 (keten and chlorine are introduced through separate distributors in a constant equimolar ratio). According to the npcv procession for about 3 hours, the introduction of reagents is complete. about 152 parts of chlorine and 82 parts of ketene. At the end of the process, the ratio between the amount of solvent and the amount of solvent and the target product is about 0.45. The resulting reaction mixture contains only T-butyrolactone, chlorine anhydride x yuraxus acid and acetic acid chloride. In the reaction mixture, dichloroacetic acid chloride and other polychlorinated by-products are completely absent. After distillation, i.e. % and the yield of acetic acid chloride is N

4 mol%.

0

If bromine is used, it is recommended that the reaction mass be used to drench. However, good results can be obtained without mixing.

Other halide anhydrides are prepared in the same way. The table shows the conditions and the target products of examples 2-5.

In examples 3-5, the input of the acid halide of the halocarboxylic acid is high, i.e. is about 9O%, and the amount of dihalocarboxylic acid halide is minimized, which results in halocarboxylic acid halide with a purity greater than 98%. In example 2

5 The yield of acid halide 1 Gd-acetic acid is about 80-90%. Chlorine dride diiodoacetic acid is extremely unstable and therefore not detected in the reaction mass in the npHMepie 2.

 ) Enyl-G-lactone may be replaced by Ji - (n-tolyl) - G-butyrolactone, with similar results being obtained.

Example 225 parts of jl-propiolactone are introduced into the reactor equipped with distributors and a thermometer. Chlorine and ketene are fed to the reactor through a distributor under a pressure of 1OO mmHg. temperature, maintain 2O-2. for about 2.5 hours. The amount of chlorine introduced into the reactor during this period of time is sufficient to maintain a slight excess of it with respect to ketene. An analysis of an almost colorless product shows that the purity of chloroacetic acid chloride is more than 98%. The yield of acetic acid chloride, which is a by-product, is about 2%. Example. The reaction is carried out analogously to example 6, h. except that 145 h of T-valerolactone is used as a solvent, and the reaction time is .. about 134 m. The following results are obtained: the yield of chloroacetic acid chloride is more than 90%; degree of purity is 99, 7%; the output of the acid chloride acetic acid - 9%; the output of the acid chloride dichloracetic acid - 0,22%; the amount of regenerated solvent is 98%. Example 8. ReacPicP is carried out similarly to Example 6, except for using 173 parts of A-caprolactone as a solvent, an initial temperature of 8 ° C (the temperature rises to about 2 ° C to 25 ° C), and a duration of about 140 m. the following results; . the yield of chlorohydride chloroacetic acid - 96%; degree of purity - 99.9%; the yield of acetic acid chloride is 3.8%; the output of the acid chloride dichloracetic acid - 0.12%; the amount of the regenerated solvent is over 9t)%. Example 9. In a reactor equipped with a distributor, a thermometer, an immersion tube and devices for p & mixing, 106 h. 7 -butyrol tone are introduced. A solution consisting of 175 parts of a 3-tyrolactone and 319.6 parts of bromine is placed in the addition funnel and combined with a dip tube using a measuring valve. The bromine solution is introduced into the reactor for about 2 hours while ketene is fed into the reactor through a distributor while the pressure of 1OO mmHg is maintained in the reactor. temperature 2 0-2 The feed rate of the bromine solution is adjusted so that an excess of bromine is maintained in the reactor. After the addition of the bromine solution, the addition of ketene is continued until the bromine color (n. Disappears from the solution. Based on the results of the analysis of the final product, it is calculated that the yield of bromoacetic acid bromide is 83%, purity 99.6%. Separation pure chloro acetic acid chloroacetic acid from acetic acid chloride and solution; 1 by means of 4-minning is not a problem due to the significant difference in the boiling points of these compounds.

Process indicators

G-butyrrlakton oC -butyl1001OO

.

5-1О20

ketenketen

monochlorides (chlorine

iodine

200100

17985

h

4248

h

Example

four

 -chloro-G-butyT-buty-rollerkton rolactone

76O

ZO

methyl ketene

chlorine

32

22 36

Halide-carbolic acid halide

Acid halide

dihalocarbo boom

acids

Subject invention

Claims (6)

1, method for producing monohaloacetic acid halides by reacting ketene and halide in an organic solvent medium, followed by isolating the target product with known techniques, characterized in that, in order to increase the yield of the target product, the lactone of general formula 1 is used as solvent (flft8 1ej- (0fijej) b - () e -0Й4ЙГ i ---  SS. % .b. R, R, o - hydrogen, halogen, alkyl Cj - Cg, phenyl, alkylfeiyl, containing Apkil C, - C-j,, a.pki Becchil, co1 holding apkil C - a, b, c - target number o or 1. 2. The method according to claim 1, of which is that the process uses the lactone of formula 1, in which L and 6 are 1 at s, rabbi O, or a is 1 at v, s , paktibix O. „. hlorangil | il chlorohydride (f. -chlorophene-chloro-propionic KHNLO1 acetic acid hlorangidrnd hlorangkrid ss, (5C-dichloroC, -dichloropropionovy kyphenylacetic acid acid j5 3. Method no. 1, of tl and h and y and i with the fact that the process uses the lactone of the general formula 1, in which and -I- 1v7 hydrogen. 4. The method according to p. 1, about tl and h and s and yc with the fact that G-butyropactone is used as a lactone and chlorine or bromine as a halogen. 25S The method according to p. 1, about tl and h and y and ys so that as lactone general formula 1 use / J-propiopactone, G-valerolactone, -caprolactone, -butyl G-butyrolactone, -chloro- / - butyro30 lactone, jb-phenyl-G-butyrolactone or - ft, “tolyl- / -butyrolactone. 6. The method according to p. 1, tl-and h ay shp ys the fact that in the process using unsubstituted ketene, 35 .7, The method according to claim 6, that is, that using halogen as chlorine. Priority points: 09.30.71 pp. 1-4; 08.08.72p. 5-7.