Catalytic process for regiospecific chlorination of alkanes,...

Details Catalytic process for regiospecific chlorination of alkanes,... Catalytic process for regiospecific chlorination of alkanes,...

2003-09-22

2004-11-30

Barts, Samuel (Department: 1621)

Organic compounds -- part of the class 532-570 series

Organic compounds

Oxygen containing

C568S335000, C568S812000, C570S190000, C570S198000

Reexamination Certificate

active

06825383

ABSTRACT:

FIELD OF THE INVENTION
The present invention relates to a new process for the chlorination of alkanes, alkenes and arenes. More particularly, the present invention relates to a process for chlorination of alkanes, alkenes and arenes using alkali metal chlorides as chlorinating agents in the presence of hypervalent iodine as catalyst. The present invention also relates to a process for the highly regiospecific chlorination of arenes using sodium chloride as a chlorinating agent in the presence of catalytic amount of sodium periodate under acidic medium (pH 2-3).
BACKGROUND OF THE INVENTION
The chlorination of alkanes, alkenes and arenes is a prominent organic reaction with wide laboratory use and industrial application. The introduction of chlorine on to aromatic rings by electrophilic substitution is an important synthetic transformation because chlorinated hydrocarbons are recognized as versatile starting materials and additives in the production of high quality insecticides, fungicides, herbicides, dyes, pharmaceuticals, etc. Since 1940, large quantities of chlorobenzene have been used in the production of DDT, a widely used insecticide. 1,4-Dichlorobenzene is a solid at room temperature its main use is as mothballs and room deodorant blocks. The major use of p-chlorotoluene is in the manufacture of p-chlorobenzotrifluoride, a key intermediate in dinitroaniline and diphenyl ether herbicides p-Chlorotoluene is an intermediate for a class of novel polyketone polymers.
In the prior art, the chlorination of arenes is known to be achieved by several methods. One of the simplest methods of chlorination of activated aromatic compounds consists of stirring the respective activated aromatic compounds such as anisole, phenol, etc. with chlorinating agent such as Cl
2
in the absence of added catalyst. Weakly activated or non-activated substrates are generally reacted with chlorine in the presence of Lewis acids such as FeCl
3
or AlCl
3
. [Ref. (1) ge la Mare, P. B. D.; in “
Electrophilic Halogenation
” Cambridge University Press, Cambridge, 1976. (2) Taylor, R.; in “
Electrophilic Aroamtic Substitution
” Wiley, Chichester, 1990, pp 362412.]. A number of other types of chlorine containing compounds such as PhICl
2
in CF
3
CO
2
H (Ref
J. Am. Chem. Soc.
1960, 82, 5823), alkyl and acyl hypochlorides (Ref
Chem. Rev.
1954, 54, 925), dichlorine monoxide (Cl
2
O) (Ref
J. Am. Chem. Soc.
1982, 104, 4680) and N-chloramines, -amides, -sulfonamides (Ref (1)
J. Chem. Soc. Perkin Trans.
2 1987, 1533, 1988, 385; 1989, 1529; 1989, 1537. (2)
Synthesis
1993, 237) have been used to perform ring chlorination of aromatics.
For the chlorination of anisole, SO
2
Cl
2
was used in the presence of the acidic zeolite such as ZF520 (Ref.
J. Org. Chem.
1990, 55, 5260). Chlorination of anisole was also carried out using t-butyl hypochlorite in the presence of acidic silica gel (Ref
Synthesis
1985, 1155). Synthesis of haloarenes was commonly performed with molecular chlorine in the presence of catalysts such as aluminium (III), iron (III), tin (IV) or zinc (II) chlorides.
In the prior art, o-chloroaniline was prepared by reducing 1-chloro-2-nitrobenzene with iron filings and HCl and p-chloroaniline was prepared by reduction of 1-chloro-4-nitrobenzene with iron filings and HCl (Ref
J. Chem. Soc.
1921, 119, 1013) or from p-chlorobenzoic acid by treatment with hydroxylamine and commercial polyphoshoric acid at 150-170° C. (Ref
J. Am. Chem. Soc.
1953, 75, 2014) or from 1,4-dichlorobenzene and NH
3
(Ref. U.S. Pat. 3,057,922) or by catalytic hydrogenation of 1-chloro-4-nitrobenzene (Ref. U.S. Pat. 3,145,231).
The catalytic liquid phase chlorination of 1,2-dichlorobenzene (1,2-DCB) is investigated over a number of zeolite catalysts using chlorine as chlorinating agent. Both K-L and K-beta are effective catalysts for the selective conversion of 1,2-DCB to 1,2,4-trichlorobenzene (1,2,4-TCB). (
Appl. Catal. A,
1997, 162, 201). A catalyst was prepared by loading 3.0% Cu(NO
3
)
2
.3H
2
O and 2.0% NaCl into zeolite KL by grinding and calcined at 550° for 6 h. Liquid-phase chlorination of PhCl in the presence of this catalyst gave a 92.5% conversion to C
6
H
4
Cl
2
with para-ortho ratio 12.2:1 (Ref. PCT Int. Appl. WO 9718893 A1 29 May 1997, 20 pp).
Chlorination of chlorobenzene in the presence of FeCl
3
and Ph 10H-phenothiazine-10-carboxylate at 50° C. in the dark for 7 h gave a product mixture containing o-dichlorobenzene, m-dichlorobenzene, p-dichlorobenzene and trichlorobenzene (Ref. PCT Int. Appl. WO 9743041 A1 20 Nov. 1997, 36 pp). The synthesis of 2,4-dichlorotoluene (2,4-DCT) was studied at 368 K and at atmospheric pressure using zeolite catalysts and the conventional catalyst, FeCl
3
, in the liquid phase chlorination of 4-chlorotoluene (4-CT) with gaseous chlorine (Cl
2
flow =0.09 mol/h) and catalyst conc. of 3.78 g/mol 4-CT. Zeolite K-L catalyzes 4-CT selectively to 2,4-DCT and is superior to the other zeolites and FeCl
3
in terms of selectivity (Ref (1)
J. Mol. Catal. A: Chem.
1997, 127, 101; (2)
Stud Sur Sci. Catal.
1998, 113, 419). A solid-liquid biphasic system (dichloromethane and neutral alumina) has been tested for the aromatic chlorination of various alkyl aryl ethers using a reagent combination of sodium chlorite and manganese(III) acetylacetonate catalyst. Efficient incorporation of a chlorine atom into the benzene ring with high para selectivity results. This catalytic system is also applicable to the regiocontrolled chlorination of polyether substrates. (Ref
J. Chem. Soc., Perkin Trans.
1 1997, 3081). Loading of zeolite NaZSM-5 with benzene and chlorine from the gas phase at −100° C. resulted in spontaneous reaction to form chlorobenzene and 1,4-dichlorobenzene as the sole products. Thermal reaction at elevated temp. (up to 0° C.) accelerates the rates toward these products and yields, in addition, some 1,3-dichlorobenzene and a small (<3%) amount of 1,2-dichlorobenzene (Ref.
J. Phys. Chem. B,
1998, 102, 7106).
tert-Butyl hypochlorite is an excellent aromatic ring chlorination agent, under mild conditions, without any catalyst, for acetanilide. High regioselectivity is observed, the product being, nearly exclusively, para-chloroacetanilide (Ref.
Synth. Commun.
1998, 28, 1891). Aromatic compounds were chlorinated in the presence of catalytic 4-PSC
6
H
4
(CH
2
)
x
SR
1
SR
2
or X
1
R
3
(SR
4
SR
3
)
y
SR
4
X
2
[PS=polymeric backbone preferably selected from polystyrene or polysiloxane, e.g. polyalkylsiloxane or polyalkylarylsiloxane; x=0−12; R
1
−R
4
=(substituted) alkyl, alkanediyl, (substituted) alkaryl, aralkyl, aryl; X
1
, X
2
=halo, SH, dialkylsulfonium halide, alkylaryl, aralkyl, (substituted) aryl; y £10000] and optionally in the presence of Lewis acid cocatalysts. Thus, m-cresol and catalytic AlCl
3
and 4-PSC
6
HCH
2
S(CH
2
)
4
SBu (PS=polystyrene) were treated with SO
2
Cl
2
to give 6.4 mol % o-chloro-m-cresol and 81 mol % p-chloro-m-cresol (Ref. Eur. Pat. Appl. EP 866048, September 1998, 58249404u, 17 pp). The active quinonoid position of various naphthoquinones is chlorinated by metal(II) chloride (CuCl
2
/HgCl
2
) and iodine in acetic acid in a single step reaction with excellent yields (Ref.
Synth. Commun.
1998, 28, 1123).
The reaction of alkyl phenyl ethers with sodium chlorite in dichloromethane in the presence of a (salen) manganese(III) complex and alumina preloaded with a small amount. of water afforded monochlorination products with unusually high para selectivities under mild conditions. The NaClO
2
-based biphasic system can also be successfully used for the regioselective monochlorination of substituted anisoles and polmethyoxybenzenes (Ref
Can. J. Chem.
1997, 75, 1905).
Tert-Butyl hypochlorite/HNa faujasite X in acetonitrile represents an efficient and highly regioselective system for mono-chlorination of a wide range of mono- and di-substituted aromatic substrates in mild conditions. Partially protonated faujasite X is far superior to amorphous silicas and

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