Organic compounds -- part of the class 532-570 series – Organic compounds – Oxygen containing
Reexamination Certificate
2000-03-14
2002-03-26
Keys, Rosalynd (Department: 1621)
Organic compounds -- part of the class 532-570 series
Organic compounds
Oxygen containing
C568S652000, C424S065000, C424S069000, C424S070100, C424S400000, C424S401000, C512S001000, C512S008000, C512S009000, C512S019000, C512S020000, C512S023000
Reexamination Certificate
active
06362378
ABSTRACT:
The present invention relates to a process for etherification of a benzyl tpe alcohol, to the products obtained and to their applications, in particular in the perfumery field.
German patent DE-4 434 823 shows that it is known to prepare hydroxybenzyl alcohol ethers by reacting the hydroxybenzyl alcohol and an alkanol in the presence of a sulphonic resin (Amberlyst®) A21). The resin is hard to regenerate and the reaction yield obtained is not very satisfactory as it is only 72%.
That process is not compatible with an industrial application.
The precise aim of the present invention is to propose a process which can overcome these disadvantages.
We have now discovered a process for etherifing a benzyl type alcohol consisting of reacting said alcohol with another alcohol in the presence of a catalyst, said process being characterized in that the etherification reaction is carried out in the presence of an effective quantity of a zeolite. This constitutes the subject matter of the present invention.
In the following description of the present invention, the term “by a benzyl type alcohol” means an aromatic heterocycle or carbocycle wherein one hydrogen atom directly bonded to the aromatic ring is replaced by a group:
and the term “aromatic” means the conventional concept of aromaticity as defined in the literature, in particular by Jerry MARCH, Advanced Organic Chemistry, 4
th
edition, John Wiley & Sons, 1992, pp. 40 ff.
For simplicity, the other alcohol used will be designated by the generic term “alkanol” which also encompasses alcohols containing cycles, in particular aromatics.
More precisely, the present invention provides a process for etherification of a benzyl alcohol with general formula (I):
where:
A represents the residue of a cycle forming all or a portion of a carbocyclic or heterocyclic aromatic, monocyclic or polycyclic system comprising at least one group:
R represents one or more substituents which may be identical or different;
R
1
and R
2
, which may be identical or different, represent a hydrogen atom, a functional group or a hydrocarbon group containing 1 to 24 carbon atoms, which can be a saturated or unsaturated, linear or branched acyclic aliphatic group; a saturated, unsaturated or aromatic, monocyclic or polycyclic cycloaliphatic group; or a saturated or unsaturated, linear or branched aliphatic group carrying a cyclic substituent;
R
1
and R
2
can form a cycle optionally comprising a further heteroatom;
n is a number equal to 5 or less.
The benzyl type alcohol used in the process of the invention has formula (I) where R
1
or R
2
represent a saturated or unsaturated, linear or branched acyclic aliphatic group.
More preferably, R
1
and R
2
represent a linear or branched alkyl group containing 1 to 12 carbon atoms, preferably 1 to 6 carbon atoms: the hydrocarbon chain can optionally be interrupted by a heteroatom (for example oxygen), by a functional group (for example —CO—) and/or may carry a substituent (for example a halogen).
The saturated or unsaturated, linear or branched acyclic aliphatic group can optionally carry a cyclic substituent. The term “cycle” preferably means a saturated, unsaturated or aromatic carbocyclic or heterocyclic cycle, preferably cycloaliphatic or aromatic, in particular cycloaliphatic comprising 6 carbon atoms in the cycle, or benzenic.
The acyclic aliphatic group can be connected to the cycle by a valence bond, a heteroatom or a functional group and examples are given below.
The cycle can optionally be substituted and examples of cyclic substituents include, inter alia, substituents such that R has the meaning given above.
R
1
and R
2
can also represent a carbocyclic group which is saturated or contains 1 or 2 unsaturated bonds in the cycle, generally containing 3 to 8 carbon atoms, preferably 6 carbon atoms in the cycle; said cycle can be substituted by substituents such as R.
R
1
and R
2
can also represent an aromatic carbocyclic group, preferably monocyclic, generally containing at least 4 carbon atoms, preferably 6 carbon atoms per cycle; said cycle can be substituted by substituents such as R.
One of groups R
1
and R
2
can represent a group CF
3
.
In formula (I), groups R
1
and R
2
can form a cycle between them, preferably containing 5 to 7 atoms, saturated or unsaturated, optionally containing a further heteroatom, for example an oxygen atom.
The invention is also applicable to benzyl type alcohols with formula (I) in which A is the residue of a cyclic compound preferably containing at least 4 atoms in the cycle, preferably 5 or 6, optionally substituted, and representing at least one of the following cycles:
an aromatic, monocyclic or polycyclic carbocycle;
an aromatic, monocyclic or polycyclic heterocycle containing at least one of the heteroatoms O, N and S.
Without in any way limiting the scope of the invention, optionally substituted residue A represents a residue:
of a monocyclic carbocyclic, aromatic compound such as benzene or toluene;
of a polycyclic condensed aromatic compound such as naphthalene;
of a monocyclic heterocyclic, aromatic compound such as pyridine, furane, or thiophene.
In the process of the invention, an aromatic compound with formula (I) is preferably used in which A represents a benzene or a naphthene ring.
The residue A of the benzyl type alcohol with formula (I) can carry one or more substituents.
The number of substituents present on the cycle depends on the carbon condensation of the cycle and on the presence or otherwise of unsaturated bonds on the cycle.
The maximum number of substituents which can be carried by the cycle can readily be determined by the skilled person.
In the present text, the term “several” generally means less than 5 substituents on an aromatic ring.
Examples of substituents are given below but this list is not limiting in nature. The following can in particular be cited:
linear or branched alkyl groups preferably containing 1 to 6 carbon atoms, more preferably 1 to 4 carbon atoms;
linear or branched alkenyl groups, preferably containing 2 to 6 carbon atoms, more preferably 2 to 4 carbon atoms;
linear or branched halogenoalkyl groups preferably containing 1 to 6 carbon atoms, more preferably 1 to 4 carbon atoms;
cycloalkyl groups containing 3 to 6 carbon atoms, preferably the cyclohexyl group;
the phenyl group;
the hydroxyl group;
the NO
2
group;
alkoxy R
3
—O— or thioether R
3
—S— groups where R
3
represents a linear or branched alkyl group containing 1 to 6 carbon atoms, more preferably 1 to 4 carbon atoms, or the phenyl group;
—N—(R
4
)
2
groups where groups R
4
, which may be identical or different, represent a hydrogen atom, a linear or branched alkyl group containing 1 to 6 carbon atoms, more preferably 1 to 4 carbon atoms, or a phenyl group;
—NH—CO—R
4
groups, where group R
4
has the meaning given above;
carboxy groups or R
4
—O—CO— derivatives where group R
4
has the meaning given above;
acyloxy or aroyloxy groups R
3
—CO—O— where group R
3
has the meaning given above;
a halogen atom, preferably a fluorine atom;
a CF
3
group.
When n is 2 or more, two groups R and the 2 successive atoms of the aromatic cycle can be connected together by an alkylene, alkenylene or alkenylidene group containing 2 to 4 carbon atoms to form a saturated, unsaturated or aromatic heterocycle containing 5 to 7 carbon atoms. One or more carbon atoms can be replaced by a further heteroatom, preferably oxygen. Thus the groups R can represent a methylenedioxy or ethylenedioxy group.
The preferred substituents are selected from electron-donating groups.
The term “electron-donating group” means a group as defined by H. C. BROWN in the work by Jerry MARCH—Advanced Organic Chemistry, chapter 9, pages 243 and 244 (1985).
The process of the invention is of particular application to benzyl type alcohols with formula (Ia):
where:
n is a number equal to 4 or less, preferably 0, 1 or 2;
group R is an electron-donating group, preferably an alkyl, alkoxy, methylenedioxy or ethylenedioxy group;
groups R
1
and R
2
, which may be identical or different, represent:
a hydrogen a
Jacquot Roland
Spagnol Michel
Keys Rosalynd
Rhodia Chimie
LandOfFree
Method for etherifying a benzyl alcohol, resulting products... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method for etherifying a benzyl alcohol, resulting products..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method for etherifying a benzyl alcohol, resulting products... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2819348