Organic compounds -- part of the class 532-570 series – Organic compounds – Oxygen containing
Reexamination Certificate
2001-10-31
2003-04-15
Richter, Johann (Department: 1621)
Organic compounds -- part of the class 532-570 series
Organic compounds
Oxygen containing
C568S327000, C568S328000, C585S532000
Reexamination Certificate
active
06548710
ABSTRACT:
The present invention relates to a process for preparing 1-indanones. It further pertains to the preparation of the corresponding indenes.
1-Indanones, which can be converted into the corresponding indene derivatives by known methods, are important intermediates in the synthesis of metallocene catalysts which typically are used in combination with a co-catalyst such as methylaluminoxane for the (co)polymerization of ethylenically unsaturated monomers, e.g., the production of isotactic polypropylene.
Several processes for preparing 1-indanones which start from either a propionic acid or an acrylic acid derivative are known in the art, but none of the prior art documents describe the process of the present invention.
For example, U.S. Pat. No. 5,840,948 describes a one-step process for preparing 1-indanones from benzene or a derivative thereof and a derivative of propionic acid carrying a leaving group in the (x-position using a Friedel-Crafts catalyst. The starting materials in this process typically contain two halogen atoms, preferably bromine or chlorine. In all examples, a dibrominated propionic acid derivative is used.
A disadvantage of the process of U.S. Pat. No. 5,840,948 is that the bromine or hydrobromic acid which results from the reaction presents a waste problem in terms of the presence and the amount of bromine-containing products.
DE 19637128 describes the reaction of an indane or tetralin derivative with a substituted acryloyl halide using a Friedel-Crafts catalyst.
A disadvantage of the process described in DE 19637128 is that the acryloyl-containing starting material is sensitive to dimerization and polymerization and that it is toxic.
R. W. Layer and I. R. MacGregor in the
Journal of Organic Chemistry,
Vol. 21, 1956, pp. 1120-1123, describe a process for the preparation of 1-indanones from &agr;-bromoaralkyl ketones. It is mentioned that &agr;-bromoaralkyl ketones are used because they are readily available. In the examples, bromine is used for preparing the &agr;-bromoaralkyl ketones.
As described above, the use of bromine and the formation of bromine-containing products presents a waste problem.
The process according to the present invention avoids these disadvantages, presents a solution to the waste problem, and allows for the preparation of 1-indanones in high yield and selectivity.
According to the present invention, a process is provided for preparing 1-indanones of formula I:
and isomers thereof, wherein R
1
, R
2
, R
3
, R
4
, R
5
, and R
6
independently represent H or a C
1
-C
20
hydrocarbon group or R
1
and R
2
or R
2
and R
3
or R
3
and R
4
and/or R
5
and R
6
together with the carbon atoms to which they are attached form a saturated or unsaturated 5- or 6-membered ring, said hydrocarbon group and/or said ring optionally containing one or more hetero atoms, said ring optionally being substituted with a C
1
-C
4
hydrocarbon group, said process comprising reacting a compound of formula II:
wherein R
1
, R
2
, R
3
, R
4
, R
5
, and R
6
have the same meaning as defined above, with a chlorinating agent, followed by reaction with a Friedel-Crafts catalyst.
It is to be noted that the regioselectivity of the ring closure reaction with the Friedel-Crafts catalyst is dependent on the presence or absence as well as the types of R-group substituents in the compound of formula II. It may be that more than one isomer is formed during this ring closure reaction, as can be seen in Example 3 described below. Hence, the invention process relates to 1-indanones of formula I and isomers thereof.
Suitable C
1
-C
20
hydrocarbon groups include C
1
-C
20
alkyl, C
1
-C
10
alkoxy, C
2
-C
20
alkenyl, C
2
-C
20
alkynyl, C
6
-C
20
aryl, C
6
-C
20
aryloxy, C
7
-C
20
arylalkyl, and C
7
-C
20
alkylaryl groups, which groups optionally may contain one or more hetero atoms such as O, Si, and halogen atoms. Said groups may be linear or branched.
Preferably, R
1
, R
2
, R
3
, R
4
, R
5
, and R
6
independently represent H or a C
1
-C
20
alkyl group or R
1
and R
2
or R
2
and R
3
or R
3
and R
4
and/or R
5
and R
6
together with the carbon atoms to which they are attached form a saturated or unsaturated 5- or 6-membered ring, said ring optionally being substituted with a C
1
-C
4
hydrocarbon group. More preferably, R
1
, R
2
, R
3
, R
4
, R
5
, and R
6
independently represent H or a C
1
-C
4
alkyl group or R
1
and R
2
or R
2
and R
3
or R
3
and R
4
and/or R
5
and R
6
together with the carbon atoms to which they are attached form a saturated or unsaturated 5- or 6-membered ring. Even more preferably, R
1
, R
4
, and R
5
represent H, R
2
and R
3
together with the carbon atoms to which they are attached form a saturated 5- or 6-membered ring, and R
6
represents H or a C
1
-C
4
alkyl group. Most preferably, R
6
represents a C
1
-C
4
alkyl group.
A particularly preferred C
1
-C
4
alkyl group is a methyl group.
Suitable starting materials of formula II are either commercially available or can be prepared by methods known to a person skilled in this art, such as by Friedel-Crafts acylation.
In the context of the present invention, it is well-known to a person skilled in the art what is meant by the term “chlorinating agent.” Chlorination of hydrocarbons is a common organic reaction and suitable chlorinating agents include chlorine, N-chlorosuccinimide, and sulfuryl chloride. For other suitable chlorinating agents the reader is referred to J. March,
Advanced Organic Chemistry,
Fourth Edition, John Wiley & Sons, New York, 1992, pp. 587-590. Preferred chlorinating agents are chlorine and sulfuryl chloride. In the process of the present invention most preferably sulfuryl chloride is used. Chlorine-containing salts that result from the chlorination reaction typically are discarded via the waste water. Surprisingly, the use of a chlorinating agent, in particular sulfuryl chloride, gave chlorinated products in a very high, nearly quantitative yield (see the Examples).
Typically, an acid or base catalyst in a conventional amount is used in the chlorination reaction. A practical acid catalyst is sulfuric acid, methanesulfonic acid or p-toluenesulfonic acid. A preferred chlorination catalyst is concentrated sulfuric acid.
Chlorination can be carried out in the absence or presence of a solvent. Suitable solvents include hydrocarbon solvents such as pentane, hexane, heptane, and toluene, and halogenated alkanes such as dichloromethane. Mixtures of solvents may also be used. Preferably, the reaction is carried out using a minimal amount of a solvent such as heptane.
An advantage of the present invention process is that it can be carried out at a relatively high concentration, which results in a higher reactor filling and a more economical process as compared to the processes of the prior art.
Chlorination can be carried out in a wide temperature range. Typically, it is performed at from 0° C. up to 100° C., preferably at from room temperature up to 100° C. A preferred temperature range for carrying out the chlorination at pilot plant scale (typically carried out in a 1,000 liters reactor) is 50 to 70° C.
Typically, the molar ratio of ketone (II) to chlorinating agent is 1:1 to 1:2. Preferably, it is 1:1 to 1:1.5, more preferably 1:1.1 to 1:1.2. Most preferably, a molar excess of about 10% of the chlorinating agent is used. Preferably, the excess of chlorinating agent is removed from the reaction product—in a conventional way, e.g., by evaporation or via destruction with water—before further reaction.
Typical reaction times for the chlorination reaction are in the order of 15 minutes to 4 hours.
In the invention process, the chlorination reaction is followed by a ring closure reaction using a Friedel-Crafts catalyst.
Suitable Friedel-Crafts catalysts are known in the art and are described, for example, in J. March,
Advanced Organic Chemistry,
Fourth Edition, pp. 535-542 . Typically, these catalysts are Lewis acid catalysts. Examples of suitable catalysts include aluminium chloride and iron (III) chloride. A preferred catalyst is aluminium chloride.
Typic
Akzo Nobel N.V.
Fennelly Richard P.
Richter Johann
Witherspoon Sikarl A.
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