EP0853607A1 - Procede de production de 1,2,4-trichlorobenzene - Google Patents

Procede de production de 1,2,4-trichlorobenzene

Info

Publication number
EP0853607A1
EP0853607A1 EP97921378A EP97921378A EP0853607A1 EP 0853607 A1 EP0853607 A1 EP 0853607A1 EP 97921378 A EP97921378 A EP 97921378A EP 97921378 A EP97921378 A EP 97921378A EP 0853607 A1 EP0853607 A1 EP 0853607A1
Authority
EP
European Patent Office
Prior art keywords
dichlorobenzene
dichlorobenzenes
mixture
trichlorobenzene
chlorinating
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP97921378A
Other languages
German (de)
English (en)
Inventor
Ramesh Krishnamurti
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Occidental Chemical Corp
Original Assignee
Occidental Chemical Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Occidental Chemical Corp filed Critical Occidental Chemical Corp
Publication of EP0853607A1 publication Critical patent/EP0853607A1/fr
Withdrawn legal-status Critical Current

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C25/00—Compounds containing at least one halogen atom bound to a six-membered aromatic ring
    • C07C25/02—Monocyclic aromatic halogenated hydrocarbons
    • C07C25/10—Trichloro-benzenes
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C17/00—Preparation of halogenated hydrocarbons
    • C07C17/093—Preparation of halogenated hydrocarbons by replacement by halogens
    • C07C17/10—Preparation of halogenated hydrocarbons by replacement by halogens of hydrogen atoms
    • C07C17/12—Preparation of halogenated hydrocarbons by replacement by halogens of hydrogen atoms in the ring of aromatic compounds
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C17/00—Preparation of halogenated hydrocarbons
    • C07C17/35—Preparation of halogenated hydrocarbons by reactions not affecting the number of carbon or of halogen atoms in the reaction
    • C07C17/358—Preparation of halogenated hydrocarbons by reactions not affecting the number of carbon or of halogen atoms in the reaction by isomerisation

Definitions

  • This invention relates to a method of making 1,2,4- trichlorobenzene from ortho and para-dichlorobenzenes.
  • it relates to isomerizing ortho and para- dichlorobenzenes, chlorinating to produce 1,2,4- trichlorobenzene, and recycling unreacted dichlorobenzene (DCB) .
  • DCB dichlorobenzene
  • the compound 1,2,4-trichlorobenzene (1,2,4-TCB) is a commercially important raw material which is used in making herbicides and fungicides. It is typically obtained as a by ⁇ product during the chlorination of benzene. However, it is very difficult to obtain 1,2,4-TCB in a high yield and purity because large amounts of the dichlorobenzenes must be recycled in order to minimize the formation of undesirable tetra and higher chlorinated products. This recycling requires a large and expensive reactor, and a substantial amount of 1,2,3- trichlorobenzene (1,2,3-TCB) is also produced, which must be separated from the 1,2,4-TCB.
  • the meta isomer preferentially reacts to produce 1,2,4-TCB and the unreacted ortho and para-dichlorobenzenes are recycled to the isomerizer.
  • manufacturers who produce the industrially more valuable p-DCB inevitably produce a large amount of o-DCB which has a more limited market. This trend is expected to lower the price of o-DCB substantially.
  • the method of this invention can take this inexpensive ortho-dichlorobenzene and convert it into a valuable product, 1,2,4-TCB.
  • Another advantage of the process is the relative ease of product separation.
  • the unreacted 1,2-DCB and 1,4-DCB can be easily distilled away from the higher boiling 1,2,4-TCB/1,2,3- TCB mixture. Additionally, the recovered DCB mixture is not wasted since it can be sent back to the isomerizer to produce more 1,3-DCB-containing DCB mixture.
  • the relatively high throughput of product in the process of this invention will also decrease the capital required for large-scale production.
  • Figure 2 is a graph giving the relative concentrations of various components in the chlorinator with the passage of time. It is further explained in the examples.
  • the mixture of 1,2,4-TCB and unreacted ortho and para- dichlorobenzene is sent through line 6 to distillation column 7, which separates the mixture into ortho and meta dichlorobenzenes, which are recycled through line 8 to isomerizer 2, and the product 1,2,4-TCB in line 9.
  • the feedstock for the process of this invention consists of dichlorobenzene, typically a mixture of ortho, meta, and para-dichlorobenzene (i.e., 1,2-dichlorobenzene, 1,3- dichlorobenzene, and 1,4-dichlorobenzene, respectively.)
  • the chlorination of benzene using a Lewis acid catalyst (and possibly also a sulfur-containing cocatalyst) produces a dichlorobenzene feedstock which is typically about 25 to 35 wt% ortho, 0.5 to 2 wt% meta, and 65 to 75 wt% para- dichlorobenzene.
  • the feed is from benzene chlorination then, of course, distillation to remove benzene, monochlorobenzene, and trichloro and higher chlorinated benzene is performed to obtain the mixture of dichlorobenzenes.
  • a feedstock of ortho-dichlorobenzene is particularly preferred because it could be potentially inexpensive. While the particular ratios of ortho, meta, and para-dichlorobenzenes produced by the isomerizer will depend upon isomerization conditions and catalyst used, a typical conposition of the product isomeric mixture is about 10 wt% ortho, about 55 wt% meta, and about 35 wt% para- dichlorobenzene.
  • the dichlorobenzene is isomerized.
  • Isomerization of dichlorobenzene is a known process and is described, for example, in U.S. Patent Nos. 2,666,085, 2,727,075, 2,819,321, and 2,920,109, herein incorporated by reference.
  • Typical isomerization conditions are at about 200 to about 250°C for a few hours at about 135 to about 415 kPa (about 20 to about 60 psi) in the presence of Lewis catalyst such as aluminum chloride, antimony chloride, or iron chloride; aluminum chloride is the preferred catalyst because it is a stronger Lewis acid.
  • the isomeric mixture of ortho, meta, and para-dichlorobenzene is treated with chlorine gas.
  • the chlorine gas is bubbled into the mixture of dichlorobenzenes in an amount that is preferably at least about stoichiometric with the amount of meta-dichlorobenzene that is present.
  • an amount of chlorine that is up to 10 mole % in excess of the amount of meta-dichlorobenzene present in the feedstock.
  • Some ortho-dichlorobenzene is also chlorinated, which produces a mixture of 1,2,4 and 1,2,3-trichlorobenzene, and some para-dichlorobenzene is chlorinated, which produces only 1,2,4-TCB.
  • Chlorination is a rapid reaction and proceeds easily at temperatures of 0 to 100°C. The chlorination can be monitored using a gas chromatograph and, to reduce the formation of undesirable by- products, the chlorination can be terminated when the presence of 1,3-dichlorobenzene falls to less than 5 wt%.
  • a catalyst is required for chlorination and usually a Lewis acid catalyst, such as aluminum chloride, antimony chloride, or ferric chloride, is used; preferably, ferric chloride is used as it is inexpensive.
  • the amount of catalyst can vary from about 10 micromoles per mole of the dichlorobenzene feed mixture up to about 1 millimole per mole of the dichlorobenzene feed mixture.
  • a cocatalyst is not required for chlorination but it can be used if desired.
  • Cocatalysts are typically sulfur- containing compounds such as elemental sulfur, aryl sulfides, and thianthrenes. Elemental sulfur is preferred as it is inexpensive and readily available.
  • the amount of cocatalyst used is typically about 10 micromoles to about 1 millimole per mole of the dichlorobenzene feed mixture.
  • the 1,2,4-TCB is separated from the unreacted dichlorobenzene. This can be accomplished most advantageously by distillation.
  • 1,2,4-TCB The yield of 1,2,4-TCB is about equal to the amount of meta-dichlorobenzene that is present.
  • Other components in the product include 1,2,3-TCB and dichlorobenzenes.
  • Purification of the 1,2,4-TCB can be accomplished, if desired, by techniques well known in the art, such as distillation and fractional crystallization.
  • the apparatus consisted of a 3-necked flask containing a magnetic stir bar and fitted with a disentrainer, a Friedrich condenser, a twin adapter for a thermometer and a polytetrafluorethylene (Teflon) tube for chlorine delivery, and an adapter containing a Teflon-backed septum for sample withdrawal.
  • the top of the condenser was connected in series with an ice-cooled empty trap (to condense any benzene and product vapors that may not condense) , a stirred water trap, and a stirred 10% aqueous KOH trap. Chlorine flow was regulated to the desired level using a needle valve and flow rate was measured using a transducer.
  • the apparatus was purged with nitrogen for 15 min, and the calculated quantities of the Lewis acid catalyst, sulfur containing co-catalyst (whenever necessary) , and the appropriate chlorobenzene were introduced into the reactor under a gentle nitrogen sweep.
  • calculated amounts of each isomer were introduced into the reactor.
  • Cold water to the condenser was turned on, the reactor flask was immersed in an oil bath pre-heated to the desired reaction temperature, nitrogen flow was stopped, and chlorine was bubbled through the solution at an appropriate rate. Reaction progress was followed by withdrawing an aliquot by syringe and quickly diluting it with dichloromethane. This solution was analyzed by gas chromatography. The results were used to generate chlorination curves which relate yield of products as a function of wt% chlorine passed though the reactor.
  • RUN NO. l The charge consisted of chlorobenzene (47.1 g, 0.418 mole), FeCl 3 (0.068 g, 4.19 x 10 "4 mole), and sulfur powder (0.0067 g, 2.09 x 10 "4 mol) . Chlorine was bubbled through the solution at the rate of 0.19 mole/min at a reaction temperature of 80°C.
  • the charge consisted of 1,2-DCB (74.5 g, 0.507 mole), FeCl 3 (0.041 g, 2.53 x 10 "4 mole), and sulfur powder (0.0081 g,
  • RUN NO. 4 The charge consisted of 1,2-DCB (24.7 g, 0.168 mole),
  • Curve 1 is 1,2-DCB
  • Curve 2 is 1,3-DCB
  • Curve 4 is 1,2,3-TCB
  • Curve 5 is 1,2,4-TCB
  • Curve 6 is 1,2,3,4-tetrachlorobenzene
  • Curve 7 is 1,2,4,5- tetrachlorobenzene.
  • Figure 2 shows that the concentration of 1,3-DCB declines more rapidly than o- and p-DCB due to its higher reactivity as it is converted into 1,2,4-TCB. Very little 1,2,3-TCB and still less tetrachlorobenzene was produced.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
  • Low-Molecular Organic Synthesis Reactions Using Catalysts (AREA)

Abstract

L'invention concerne un procédé de production de 1,2,4-trichlorobenzène. On isomérise du dichlorobenzène contenant moins qu'une quantité isomère de métadichlorobenzène, pour produire un mélange isomère de dichlorobenzènes sensiblement riches en métadichlorobenzène. On chlore le mélange isomère de dichlorobenzènes à l'aide de chlore gazeux pour produire du 1,2,4-trichlorobenzène et des dichlorobenzènes n'ayant pas réagi. On sépare par distillation le mélange de 1,2,4-trichlorobenzène et de dichlorobenzènes n'ayant par réagi et on recycle les dichlorobenzènes n'ayant pas réagi dans l'isomériseur.
EP97921378A 1996-05-28 1997-04-28 Procede de production de 1,2,4-trichlorobenzene Withdrawn EP0853607A1 (fr)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
US65443496A 1996-05-28 1996-05-28
US654434 1996-05-28
PCT/US1997/006941 WO1997045389A1 (fr) 1996-05-28 1997-04-28 Procede de production de 1,2,4-trichlorobenzene

Publications (1)

Publication Number Publication Date
EP0853607A1 true EP0853607A1 (fr) 1998-07-22

Family

ID=24624841

Family Applications (1)

Application Number Title Priority Date Filing Date
EP97921378A Withdrawn EP0853607A1 (fr) 1996-05-28 1997-04-28 Procede de production de 1,2,4-trichlorobenzene

Country Status (4)

Country Link
EP (1) EP0853607A1 (fr)
JP (1) JP3002546B2 (fr)
AU (1) AU2742997A (fr)
WO (1) WO1997045389A1 (fr)

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105820032A (zh) * 2016-05-03 2016-08-03 四川福思达生物技术开发有限责任公司 一种1,2,4-三氯苯的生产工艺
CN105801334A (zh) * 2016-05-03 2016-07-27 四川福思达生物技术开发有限责任公司 一种2,5-二氯苯酚的合成方法
CN105859550B (zh) * 2016-05-06 2019-03-05 四川福思达生物技术开发有限责任公司 一种麦草畏的制备工艺
CN105859508B (zh) * 2016-05-06 2019-03-05 四川福思达生物技术开发有限责任公司 一种制备麦草畏的工艺
CN105968000B (zh) * 2016-05-06 2019-03-05 四川福思达生物技术开发有限责任公司 一种制备麦草畏的方法

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1923419A (en) * 1932-03-16 1933-08-22 Dow Chemical Co Preparation of trichlorobenzene
BE513656A (fr) * 1951-10-04
US4089909A (en) * 1976-09-22 1978-05-16 Ppg Industries, Inc. Separation of dichlorobenzene isomers
US4835327A (en) * 1986-12-05 1989-05-30 Ppg Industries, Inc. Method for producing 1,2,4-trichlorobenzene

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO9745389A1 *

Also Published As

Publication number Publication date
JP3002546B2 (ja) 2000-01-24
AU2742997A (en) 1998-01-05
WO1997045389A1 (fr) 1997-12-04
JPH10510852A (ja) 1998-10-20

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