CS237525B1 - Process for preparing chlorinated phenylalkoxypropanes - Google Patents

Abstract

A method for preparing chlorinated phenylalkoxypropanes of the general formula I, where R is C^ to C4 alkyl or isoalkyl and X is a hydrogen or chlorine atom, consisting in that the reaction mixture containing, per 1 mol of chlorinated phenylpropane of the general formula II, where X has the above-mentioned meaning, 5 to 50 mol of aliphatic alcohol of the general formula III, where R has the above-mentioned meaning, is heated alone or preferably in the presence of 2 to 15 mol % of chlorides of zinc, iron (II), iron (III), aluminum, tin (II), tin (IV), cerium (III), cerium (IV), antimony (III), antimony (V), or rubidium as a catalyst to 100 to 160 °C under normal or elevated pressure up to 2 MPa. Most of the above chlorinated phenylalkoxypropanes are new substances, characterized by a pleasant odor and can be important organic intermediates.

Description

The invention relates to a method for the preparation of chlorinated phenylalkoxypropanes. Chlorinated phenylalkoxypropanes can be valuable organic intermediates. Of this group of substances, only 1,1-dichloro-3-methoxy-3-phenylpropane and 1,1,1-trichloro-3-methoxy-3-phenylpropane are known so far, which are formed in yields of 33 and 20%, respectively, by radical addition of chloroform and carbon tetrachloride to styrene in methanol under catalysis by ferric chloride and copper chloride /J. Chem. Soc., 1963, 1887, 3921/.

The subject of the invention is a process for the preparation of chlorinated phenylalkoxypropanes of the general formula I,

C _g H ₅ CH/OR/CH ₂ CXCl ₂ /1/ where R is up to C^ alkyl or isoalkyl and X is a hydrogen or chlorine atom, consisting in that the reaction mixture containing per 1 mol of chlorinated phenylpropane of the general formula II, c ₆ h ₅ chchich ₂ cxci ₂ /11/ where X has the above meaning, 5 to 50 mol of aliphatic alcohol of the general formula III,

ROH /111/ where R has the above meaning, is heated alone or preferably in the presence of 2 to 15 mol % of chlorides of zinc, iron (II), iron (III), aluminum, tin (II), tin (IV), cerium (III), cerium (IV), antimony (III), antimony (V), or rubidium as catalysts at 100 to 160 °C under normal or elevated pressure up to 20 MPa.

The starting chlorinated phenylpropanes of general formula II, such as 1,1,3-trichloro-3-phenylpropane and 1,1,1,3-tetrachloro-3-phenylpropane, are easily available by catalytic radical addition of chloroform (Czech Patent No. 226,974) or tetrachloromethane (Czech Patent No. 209,347) to styrene, respectively.

The reaction of chlorinated phenylpropanes with alcohols according to the invention takes place even in the absence of catalysts, but it can be significantly accelerated in the presence of chlorides of certain metals as catalysts.

The advantage of the method for preparing chlorinated alkoxyphenylpropanes according to the invention is its simplicity, unambiguous chemical course, easy isolation and 70 to 92% yields of products. For example, the reaction of 1,1,1,3-tetrachloro-3-phenylpropane /1 mol/ with n-propanol /20 mol/ catalyzed by zinc chloride /0.05 mol/ after 5 hours at 140 °C yields 1,1,1-trichloro-3-n-propoxy-3-phenylpropane in 90% yield. According to another example, 1,1,3-trichloro-3-phenylpropane /1 mol/ with ethanol /15 mol/ in the presence of zinc chloride /0.05 mol/ for 7 hours at 140 °C can be prepared 1,1-dichloro-3-ethoxy-3-phenylpropane and its yield corresponds to 84%. In addition to the above-mentioned 1,1-dichloro-3-methoxy-3-phenylpropane and 1,1,1-trichloro-3-methoxy-3-phenylpropane obtained by other methods, the chlorinated alkoxyphenylpropanes of the general formula I prepared according to the invention are novel substances. The examples given describe in more detail the process for preparing the chlorinated alkoxyphenylpropanes of the general formula I according to the invention, without limiting or delimiting its validity.

Example 1

5.16 g (0.02 mol) of 1,1,1,3-tetrachloro-3-phenylpropane, 12.8 g (0.4 mol) of methanol and 0.136 g (0.001 mol) of zinc chloride are placed in a thick-walled glass ampoule, the ampoule is sealed and its contents are heated at 140 °C for 5 hours with vibratory stirring. After cooling, excess methanol is distilled off from the reaction mixture, the concentrated residue is diluted with water, the organic phase is separated and the aqueous phase is extracted twice with 15 ml of chloroform. The organic phase and extracts are combined, chloroform is distilled off under normal pressure, the residue is distilled under reduced pressure and 4.0 g (88%) of 1,1,1-trichloro-3-methoxy-3-phenylpropane with a boiling point of 119-122°C/1.87 kPa is obtained.

Example 2

4.47 g (0.02 mol) of 1,1,3-trichloro-3-phenylpropane, 12.8 g (0.4 mol) of methanol and 0.272 g (0.002 mol) of zinc chloride are placed in a thick-walled glass ampoule, the ampoule is sealed and its contents are heated for 5 hours at 140 °C with vibratory stirring. The reaction mixture is worked up according to Example 1 and 3.85 g (79%) of 1,1-dichloro-3-methoxy-3-phenylpropane with a boiling point of

119 to 120 °C/2.0 kPa.

Examples 3 to 6

1,1,1,3-tetrachloro-3-phenylpropane, aliphatic alcohol of general formula III and zinc chloride in the molar ratio given in Table A are placed in a thick-walled glass ampoule, the ampoule is sealed and its contents are heated with vibratory stirring to 140 °C for the time given in Table A. The reaction mixture is treated according to Example 1 and 1,1,1-trichloro-3-alkoxy-3-phenylpropane of general formula I is obtained, where X is a chlorine atom, in the yield given in Table A.

Table A

Example Alcohol ROH Molar ratio*/ Response time h Yield % 3 ethanol 1:17.5:0.05 5 90 4 n-propanol 1:20:0.05 5 90 5 2-propanol 1:20:0.05 10 85' 6 n-butanol 1:10:0.05 10 88 ^+/Z Molar ratio of 1,1,1,3-tetrachloro- 3-phenylpropane : alcohol : catalyst P h o r k lady 7 to 17 To thick-walled glass ampoules 1,1,3-trichloro- -3-phenylpropane, , aliphatic alcohol general formula III and catalyst in the molar ratio given in Table B, ampoule is will stop and its contents are mixed with vibratory agitation heats to temperature and after the time specified in the table B. Reaction- mixture is processed according to example 1 and 1,1-dichloro- -3-Alkoxy-3-phenylpropane general formula I , where X is a hydrogen atom, in the yield shown in Table B. Table B Example Alcohol Catalyst Molar ratio ⁺ / Temperature Time °C reaction h Yield % 7 ethanol ZnC^ 1 : 15 : 0.05 140 7 84 8 n-propanol ZnCl ₂ 1 : 17 : 0.02 140 9 82 9 2-propanol ZnCl^ 1 : 20 : 0.05 140 15 79 10 n-butanol ZnCl ₂ 1 : 15 : 0.05 140 15 75 11 methanol FeCl^ 1 : 20 : 0.05 140 11 92 12 methanol A1C1 ₃ 1 : 5 : 0.02 140 5 70 13 methanol SnCl ₂ 1 : 10 : 0.05 120 7 82 14 methanol CeCl^ 1 : 20 : 0.05 140 5 70 15 methanol sbcl ₃ 1 : 20 : 0.05 140 .5 75 • 16 methanol RBC1 1 : 20 : 0.05 140 5 73 17 methanol without catalyst 1 : 20 .: 0 140 10 90

+/

Molar ratio of 1,1,3-trichloro-3-phenylpropane : alcohol : catalyst

Claims (2)

SUBJECT OF THE INVENTION A process for the preparation of chlorinated phenylalkoxypropanes of the formula I, C _g H ₅ CH / OR / CH ₂ CXCL _2/1 / wherein R is and alkyl or isoalkyl and X is hydrogen or chlorine, characterized in that the reaction mixture containing 1 mol of the chlorinated phenylpropane of formula II, C ₆ H ₅ chcich CXCI _{2 2/11} / wherein X has the meaning given above, from 5 to 50 moles of aliphatic alcohol of general formula III ROH (111) wherein R is as hereinbefore defined is heated alone or preferably in the presence of 2 to 15 mole% zinc, iron (II), iron (III), aluminum, tin (II), tin (IV), cerium (III), cerium (IV), antimony (III), antimony (V), or rubidium catalysts at 100 to 160 ° C at normal or elevated pressure up to 2 MPa.