U.S. patent application number 09/776960 was filed with the patent office on 2001-08-02 for method for preparing functional halosilanes.
Invention is credited to Lee, Michael Kang-Jen, Roy, Aroop Kumar.
Application Number | 20010011140 09/776960 |
Document ID | / |
Family ID | 23399773 |
Filed Date | 2001-08-02 |
United States Patent
Application |
20010011140 |
Kind Code |
A1 |
Lee, Michael Kang-Jen ; et
al. |
August 2, 2001 |
Method for preparing functional halosilanes
Abstract
The present invention relates to a method for preparing
functional halosilanes by reacting (A) a cyclic silyl ether having
the formula 1 wherein each R is independently selected from a
hydrocarbyl group or a halogen-substituted hydrocarbyl group having
1 to 20 carbon atoms, each R' is independently selected from a
group consisting of hydrogen and R and b is 3, 4 or 5; and (B) a
halogen-functional compound having a formula selected from 2
wherein G is an m-valent organic group, m is at least 2, X is
halogen, R" is independently selected from hydrocarbyl groups or
halogen-substituted hydrocarbyl groups having 1 to 20 carbon atoms,
j is an integer having a value of 1 to 3 and k is an integer having
a value of 1 to 3.
Inventors: |
Lee, Michael Kang-Jen;
(Midland, MI) ; Roy, Aroop Kumar; (Midland,
MI) |
Correspondence
Address: |
Dow Corning Corporation
Intellectual Property Department - CO1232
P.O. Box 994
Midland
MI
48686-0994
US
|
Family ID: |
23399773 |
Appl. No.: |
09/776960 |
Filed: |
February 5, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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|
09776960 |
Feb 5, 2001 |
|
|
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09356018 |
Jul 19, 1999 |
|
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|
6235920 |
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Current U.S.
Class: |
556/400 |
Current CPC
Class: |
C07F 7/123 20130101;
C07F 9/3264 20130101 |
Class at
Publication: |
556/400 |
International
Class: |
C07F 007/02 |
Claims
That which is claimed is:
1. A functional halosilane comprising the reaction product of (A) a
cyclic silyl ether having a formula selected from the group
consisting of 13wherein each R is independently selected from a
hydrocarbyl group or a halogen-substituted hydrocarbyl group having
1 to 20 carbon atoms, each R' is independently selected from a
group consisting of hydrogen and R and b is 3, 4 or 5; and (B) a
halogen-functional compound having a formula selected from
14wherein G is an m-valent organic group selected from hydrocarbyl
groups or hydrocarbyl groups containing at least one hetero atoms
selected from oxygen, nitrogen or sulfur, m is at least 2, X is
halogen, R" is independently selected from hydrocarbyl groups or
halogen-substituted hydrocarbyl groups having 1 to 20 carbon atoms,
j is an integer having a value of 1 to 3 and k is an integer having
a value of 1 to 3.
2. The functional halosilane according to claim 1, wherein X is
chlorine.
3. The functional halosilane according to claim 2, wherein said
cyclic silyl ether has a formula selected from 15wherein each R is
independently selected from methyl, phenyl or trifluoropropyl and
R' is selected from hydrogen or methyl.
4. The functional halosilane according to claim 3, wherein said
cyclic silyl ether is 2,2,4-trimethyl-1-oxa-2-silacyclopentane.
5. The functional halosilane according to claim 4, wherein said
halogen-functional compound has the formula 16wherein G is an
alkylene group having 6 to 20 carbon atoms.
6. The functional halosilane according to claim 4, wherein said
halogen-functional compound has the formula selected from 17wherein
R" is selected from alkyl groups having 1 to 10 carbon atoms,
alkenyl groups having 2 to 20 carbons or aryl groups having 6 to 10
carbons, j is an integer having a value of 1 to 3 and k is an
integer having a value of 1 to 3.
7. The functional halosilane according to claim 4, wherein said a
halogen-functional compound has the formula selected from 18wherein
R" is selected from alkyl groups having 1 to 10 carbon atoms,
phenyl or tolyl.
8. The functional halosilane according to claim 1, wherein G
contains at least one hetero atom.
9. The functional halosilane according to claim 8, wherein X is
chlorine and said cyclic silyl ether has a formula selected from
19wherein each R is independently selected from methyl, phenyl or
trifluoropropyl and R' is selected from hydrogen or methyl.
10. The functional halosilane according to claim 9, wherein said
cyclic silyl ether is 2,2,4-trimethyl-1-oxa-2-silacyclopentane.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This patent application is a divisional of U.S. patent
application Ser. No. 09/356,018, filed Jul. 19, 1999, which is now
pending.
FIELD OF THE INVENTION
[0002] The present invention relates to a method for preparing
functional halosilanes. More particularly, the invention relates to
a method for reacting a cyclic silyl ether with certain
halogen-functional compounds.
BACKGROUND OF THE INVENTION
[0003] Organofunctional silanes, such as aminoalkyl-,
mercaptoalkyl-, phosphinoalkyl-, and the like, represent an
important class of silicon compounds. These silanes find extensive
application in commercial products such as coupling agents,
adhesion promoters and crosslinkers, inter alia. These compounds
can also be used to functionalize siloxane polymers, thereby
enhancing their advantageous properties in various silicone
applications.
[0004] A number of existing methods for preparing organofunctional
silanes depend on multi-step synthetic routes that suffer from poor
yield and waste problems in one or more of the steps. For example,
preparation of acid chloride functional silanes requires a two-step
process wherein a carboxy acid-functional silane is first
synthesized and this, in turn, is reacted with thionyl chloride.
The latter compounds find utility in the preparation of
silicone-organic copolymers and organofunctional silanes that can
be derived from their well-known reactivity. There is, therefore, a
need for improved methods which can provide various functional
silanes in an efficient and economical manner.
[0005] A simple method for preparing carbinol-functional siloxanes
has been disclosed by Burns et al. in U.S. Pat. No. 5,290,901. In
this procedure, a cyclic silyl ether is reacted with an
organosiloxane or organosiloxane resin. The reactivity of such a
cyclic silyl ether was studied by R. J. P. Corriu et al.(Journal of
Organometallic Chemistry, 114, 21-33 (1976)) and these authors
disclose the reaction of an oxasilacyloalkane with acetyl chloride
to form an acetate-functional chlorosilane.
[0006] However, there is no expectation that the outcome of the
reaction of a yclic silyl ether with any given halogen-functional
component, other than the simple acyl halide illustrated by Corriu
et al., could be predicted without experimentation. Thus, neither
the publication by Corriu et al. nor any other prior art know to
applicants teaches the reaction of such cyclic silyl ethers with
the particular halogen-functional compounds of the present
invention to prepare functional halosilanes.
SUMMARY OF THE INVENTION
[0007] It has now been discovered that several classes of
organofunctional silanes can be prepared in high yields by reacting
a cyclic silyl ether and certain activated halogen compounds.
Surprisingly, even closely related structures to the select
halogen-functional compounds of the invention did not react with
the cyclic silyl ether. The products of reaction find utility as
intermediates for the preparation of silicone polymers and
silicone-organic copolyrners, formation of supported catalysts and
for use in surface modification.
[0008] The present invention, therefore, relates to a method for
preparing a functional halosilanes by reacting
[0009] (A) a cyclic silyl ether having the formula 3
[0010] wherein each R is independently selected from a hydrocarbyl
group or a halogen-substituted hydrocarbyl group having 1 to 20
carbon atoms, each R' is independently selected from a group
consisting of hydrogen and R and b is 3, 4 or 5; and (B) a
halogen-functional compound having a formula selected from 4
[0011] wherein Q is a monovalent group having 2 to 20 carbon atoms
selected from alkenyl groups, aralkenyl groups or a heterocyclic
hydrocarbyl group having oxygen, nitrogen or sulfur hetero atoms in
its ring, G is an m-valent organic group, m is at least 2, X is
halogen, R" is independently selected from hydrocarbyl groups or
halogen-substituted hydrocarbyl groups having 1 to 20 carbon atom,
j is an integer having a value of 1 to 3 and k is an integer having
a value of 1 to 3.
[0012] The invention also relates to the products formed by the
above-described reactions.
DETAILED DESCRIPTION OF THE INVENTION
[0013] In the method of the present invention, a cyclic silyl ether
represented by formula (I) is reacted with one of the
halogen-functional compounds represented by formulas (i) through
(vi).
[0014] Cyclic silyl ether (A) has the formula (I) 5
[0015] wherein each R is independently selected from monovalent
hydrocarbyl groups or halogen-substituted hydrocarbyl groups having
1 to 20 carbon atoms, with the proviso that R can not have terminal
(i.e., vinylic) unsaturation. Each unsubstituted R group can be an
alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having
3 to 10 carbon atoms, an alkenyl group having 3 to 20 carbon atoms
or an aryl group having 6 to 20 carbon atoms. Specific non-limiting
examples of R groups include methyl, ethyl, propyl, isopropyl,
butyl, tert-butyl, pentyl, cyclopropyl, cyclopentyl, benzyl,
beta-phenylethyl, gamma-tolylpropyl, phenyl, tolyl, xylyl, and
naphthyl. For the purposes of the present invention, the groups R
and R' must be inert with respect to the reaction between
components (A) and (B), further described infra. Non-limiting
examples of substituted groups may be illustrated by chloropropyl,
3,3,3-trifluoropropyl, perfluoropropyl, chlorophenyl,
pentafluorophenyl and nonafluorobutyl. In formula (I), each R' is
independently selected from hydrogen or the above described R group
and b is 3, 4 or 5.
[0016] Preferably, component (A) has one of the following
structures 6
[0017] wherein R and R' have their previously defined meanings. In
formulas (II) and (III) each R is preferably independently selected
from methyl, phenyl or trifluoropropyl (i.e.,
CF.sub.3CH.sub.2CH.sub.2--) and R' is either hydrogen or methyl.
Most preferably, R and R' is each methyl. A particularly preferred
component (A) is 2,2,4-trimethyl-1-oxa-2- silacyclopentane having
the structure 7
[0018] wherein Me hereinafter denotes a methyl group.
[0019] The above-described cyclic silyl ethers are known in the art
and may be prepared by methods reviewed in, e.g., U.S. Pat. No.
5,290,901.
[0020] In a first embodiment of the present invention, the above
described cyclic silyl ether (A) is reacted with an acyl halide of
the formula 8
[0021] wherein Q is a monovalent group having 2 to 20 carbons
selected from alkenyl groups, aralkenyl groups or a heterocyclic
hydrocarbyl group which contains at least one oxygen, nitrogen or
sulfur hetero atom in its ring with the proviso that these
heterocyclic groups do not react with component (A). In formula
(i), X is a halogen group selected from fluorine, chlorine, bromine
or iodine, preferably chlorine. For the purposes of this first
embodiment, the carbon-carbon double bond (i.e., --C.dbd.C--) of Q
is preferably conjugated with the --C.dbd.O group of component (i).
The Q group may be illustrated by vinyl, isopropenyl, allyl,
hexenyl, 2-furonyl, acryl, methacryl, 2-phenylethyl, 2-thiophene
and 2quinoxalinyl, inter alia. Particularly preferred Q groups are
vinyl and isopropenyl. Specific examples of component (i) include
acryloyl chloride, methacryloyl chloride, cinnamoyl chloride,
2-furoyl chloride, 2-thiophene carbonyl chloride, 2-thiopheneacetyl
chloride, 2-quinoxaloyl chloride and nicotinoyl chloride.
[0022] Compounds represented by formula (i) are known in the art
and specific preferred compounds according to the first embodiment
include acryloyl chloride, methacryloyl chloride and cinnamoyl
chloride.
[0023] The reaction between components (A) and (i) can be carried
out either neat or in a non-reactive organic solvent such as
toluene, hexane, dibutyl ether or cyclohexane, typically at a
temperature of about 0 to 150.degree. C. These components are
generally combined so as to provide about one equivalent of acid
halide group for each equivalent of the cyclic silyl ether.
Preferably, the reaction is conducted without solvent at a
temperature of 20 to 100.degree. C. Although stoichiometric
quantities of (A) and (i) can be used (i.e., one equivalent of
component (A) to one equivalent of component (i)), it is preferred
to use an excess of up to about 25% of component (i). As mentioned
above, it was surprisingly observed that closely related acyl
halide compounds, such as allyl chloroformate, and
halide-functional hydrocarbons, such as allyl chloride, did not
react with the cyclic silyl ether under similar conditions.
[0024] Upon completion of the above reaction, the product can be
purified by distillation, extraction or precipitation, as
appropriate, using conventional methods. According to this first
embodiment, the reaction product contains a reactive halide group
on silicon as well as unsaturated functionality (or heterocyclic
functionality) at opposite ends of its molecule. Therefore, it
finds utility as a co-monomer in the preparation of
silyl-flnctional polymers via free-radical polymerization of
monomers such as methyl acrylate and styrene, or in the preparation
of heterocyclic-functional siloxane polymers, inter alia.
Additionally, these products may be used to end-cap anionic living
siloxane polymers to prepare vinyl-functional silicone
macromonomers.
[0025] In a second embodiment of the present invention, cyclic
silyl ether (A) is reacted with an acyl halide of the formula 9
[0026] wherein G is an m-valent organic group selected from
hydrocarbyl groups or heterocyclic groups containing one or more
hetero atoms selected from oxygen, nitrogen or sulfur with the
proviso that these heterocyclic groups do not react with component
(A). In formula (ii), X is as defined above and m is at least 2.
There is no particular limitation on the size of group G and it may
be a low molecular weight species such as alkylene, arylene or
halogen-substituted versions of these two types, preferably having
6 to 20 carbon atoms. Examples of low molecular weight G groups
wherein m=2 include methylene, ethylene, propylene, butylene,
isobutylene, hexylene, phenylene and naphthylene. Specific
compounds wherein m=2 include oxaloyl chloride, adipoyl chloride,
terephthaloyl chloride, 2,5-thiophene diacid chloride and
2,6-pyridinedicarbonyl dichloride. Examples of component (ii)
wherein m=3 and m=4, respectively, are represented by the following
two formulas 10
[0027] A preferred low molecular weight divalent acyl halide
according to the second embodiment of the instant method is
selected from adipoyl chloride or terephthaloyl chloride.
[0028] It is also contemplated that G in formula (ii) can be a
polymeric group having a valence of at least 2, these materials
also being known in the art. Thus, for example, carboxylic
acid-ended polyesters (i.e., m 2) can be converted to polymeric
acyl halides by reacting with an inorganic acid halide such as
phosphorous trichloride, phosphorous pentachloride or thionyl
chloride. Similarly, higher values of m can be achieved by the
above-described conversion of carboxyl-grafted polymers to the
corresponding polymeric acyl halides. For example, poly(acrylic
acid) or poly(methacrylic acid) can be so reacted to provide a
polymer having a plurality of acyl halide groups pendant to the
main chain.
[0029] The reaction between components (A) and (ii) can again be
carried out either neat or in an organic solvent and the product
subsequently purified, as described in connection with the first
embodiment. In this case, however, components (A) and (ii) are
reacted in a ratio designed to leave at least one equivalent of
acid halide on the product and the respective amounts can readily
be determined by routine experimentation. For example, when m=2
(e.g., adipoyl chloride), one mole of (A) is preferably reacted
with approximately one mole of (ii); when m=3, one or two moles of
(A) are reacted with about one mole of (ii), and so on.
[0030] The low molecular weight reaction products according to the
second embodiment find utility as, e.g., difunctional (i.e., m=2)
monomers which can be used in the synthesis of thermoplastic
copolymers. For example, an acid-functional or ester-functional
disiloxane can be prepared by hydrolysis or alcoholysis of the
above reaction product. The resulting end-capping agent can be
equilibrated with a diorganocyclopolysiloxane (e.g., in the
presence of acid or base catalyst) to prepare acid-functional or
ester-functional telelechelic siloxane polymers. Such telechelic
systems can be subsequently reacted with organic diols or diamines
to provide silicone-organic copolymers (e.g., silicone-polyesters
or silicone-polyamides). Products wherein m=3, 4 could be utilized
after complete alcoholysis (e.g., with methanol) to prepare pendent
ester-functional siloxanes (i.e., by condensation with SiOH ended
siloxanes) or to prepare pendent alkoxysilyl-functional polyamides
via reaction with organic diamines.
[0031] Polymeric systems according to the second embodiment contain
reactive silyl functionality as well as acyl halide functionality
and can be used to modify functional polymers such as polyesters
and polyamides. Further, the latter systems can be employed as
surface modifying additives for paints and coatings.
[0032] In a third embodiment of the present invention, the cyclic
silyl ether is reacted with a halogen-containing organophosphorous
compound having a formula selected from 11
[0033] wherein R" is independently selected from hydrocarbyl groups
or halogen-substituted hydrocarbyl groups having 1 to 20 carbon
atoms, j is an integer having a value of 1 to 3, k is an integer
having a value of 1 to 3 and X is halogen, again preferably
chloride. In the above formulas, R" can be alkyl, alkenyl,
cycloalkyl, aryl, arylalkyl, alkylaryl, or halogen-substituted
versions thereof. Specific non-limiting examples of R" groups
include methyl, ethyl, propyl, isopropyl, butyl, tert-butyl,
pentyl, cyclopropyl, cyclopentyl, vinyl, allyl, hexenyl, benzyl,
beta-phenylethyl, gamma-tolylpropyl, phenyl, tolyl, xylyl,
naphthyl, chloropropyl, 3,3,3-trifluoropropyl, perfluoropropyl,
chlorophenyl, pentafluorophenyl and nonafluorobutyl. It is
preferred that R" is selected from alkyl groups having 1 to 10
carbon atoms, alkenyl groups having 2 to 20 carbons or aryl groups
having 6 to 10 carbons.
[0034] Compounds represented by formulas (iii) and (iv) are known
in the art and preferred compounds according to the third
embodiment include the following structures PCl.sub.3, PBr.sub.3,
(i-Pr).sub.2PCl, PhPCl.sub.2, Ph.sub.2PCl, P(O)Cl.sub.3,
Ph.sub.2P(O)Cl and MeP(O)Cl.sub.2, wherein Ph and i-Pr hereinafter
denote phenyl and isopropyl groups, respectively.
[0035] The reaction between components (A) and any of the compounds
(iii) and (iv) can be carried out either neat or in an organic
solvent and the product subsequently purified, as described in
connection with the first embodiment. In this case, component (A)
and component (iii) or (iv) are combined in a ratio designed to
react at least one equivalent of halide group. As before, it is
preferred to use an excess of up to about 25% of component (iii) or
(iv) with respect to component (A) in the above described
reaction.
[0036] The products according to the third embodiment find utility,
e.g., in the preparation of supported catalysts, as adhesion
promoters or as hydrosilylation cure inhibitors/modifiers. For
example, they can be co-hydrolyzed with silicon tetrachloride in
the presence of silica or reacted as a slurry with silica in the
presence of a base.
[0037] In a fourth embodiment of the present invention, the cyclic
silyl ether is reacted with a halogen-functional organosulfur
compound having a formula selected from 12
[0038] wherein R" and X have their previously defined meanings. In
this embodiment, it is preferred that R" is selected from alkyl
groups having 1 to 10 carbon atoms, phenyl or tolyl and X is
chlorine. Compounds represented by formulas (v) and (vi) are known
in the art and can be illustrated by the following structures:
[0039] PhS(O)Cl, CF.sub.3S(O)Cl, n-BuSCl, PhSCl and MeSCl, wherein
n-Bu hereinafter denotes n-butyl.
[0040] The reaction between components (A) and compound (v) or (vi)
can be carried out either neat or in an organic solvent and
subsequently purified, as described in connection with the first
embodiment. In this case, component (A) and component (v) or (vi)
are reacted in an equimolar ratio and, as before, it is preferred
to use an excess of up to about 25% of component (v) or (vi) with
respect to component (A). Here it was again surprisingly observed
that closely related halogen-fulnctional organosulfur compounds,
such as benzenesulfonyl chloride, did not react with the cyclic
silyl ether.
[0041] The products of the fourth embodiment find utility in the
preparation of supported catalysts and as hydrosilation cure
inhibitors/modifiers.
EXAMPLES
[0042] The following examples are presented to further illustrate
the method of this invention, but are not to be construed as
limiting the invention, which is delineated in the appended claims.
All parts and percentages in the examples are on a weight basis and
all measurements were obtained at 25.degree. C. unless indicated to
the contrary.
Example 1
[0043] A 250 mL, 3-necked flask fitted with a magnetic stirrer,
addition funnel, nitrogen inlet and reflux condenser was charged
with 32.51 g (0.25 mole) of
2,2,4-trimethyl-1-oxa-2-silacyclopentane. The flask was heated to
60.degree. C. under nitrogen and 31.42 g (0.30 mole) of
methacryloyl chloride were added slowly through the addition funnel
over a period of 30 minutes. After stirring for 17 hours at
60.degree. C., the reaction was stopped by cooling the flask to
room temperature. A total of 58.0 g of crude product was mixed with
0.05 g of CuCl.sub.2 and distilled at 94.degree. C./1 mm Hg to
obtain 19.8 g of methacryloxyisobutyl-dimethy- lchlorosilane having
a purity of 97%. The following structure was verified by .sup.29Si
nuclear magnetic resonance (NMR):
[0044] CH.sub.2.dbd.C(Me)HC(O)--O-- CH.sub.2C(Me)H
CH.sub.2--Si(Me.sub.2)C- l
Example 2
[0045]
[0046] A 250 mL, 3-necked flask fitted with a magnetic stirrer, a
nitrogen inlet and a reflux condenser was charged with 14.44 g
(0.11 mole) of 2,2,4-trimethyl-1-oxa-2-silacyclopentane. The flask
was heated to 54.degree. C. under nitrogen and 31.56 g (0.13 mole)
of diphenylphosphinic chloride were injected. After stirring for 17
hours at 54.degree. C., the reaction was stopped by cooling the
flask to room temperature. Nearly 100% completion of the reaction
resulted in the following structure, as verified by NMR:
[0047] Ph.sub.2P(.dbd.O)--O-- CH.sub.2C(Me)H
CH.sub.2--Si(Me.sub.2)Cl Example 3
[0048] A 100 mL, 3-necked flask fitted with a magnetic stirrer, a
nitrogen inlet and a reflux condenser was charged with 5.03 g
(0.037 mole) of 2,2,4-trimethyl-1-oxa-2-silacyclopentane. The flask
was heated to 50.degree. C. under nitrogen and 7.85 g (0.043 mole)
of adipoyl chloride were injected. After stirring for 21 hours at
50.degree. C., the reaction was stopped by cooling the flask to
room temperature. Nearly 100% completion of the reaction resulted
in the following structure, as verified by NMR:
[0049] ClC(O)--CH.sub.2CH.sub.2CH.sub.2CH.sub.2--C(O)--O--
CH.sub.2C(Me)HCH.sub.2--Si(Me.sub.2)Cl.
(Comparative) Example 4
[0050] A 250 mL, 3-necked flask fitted with a magnetic stirrer, a
nitrogen inlet and a reflux condenser was charged with 4.06 g
(0.031 mole) of 2,2,4-trimethyl-1-oxa-2-silacyclopentane. The flask
was heated to 60.degree. C. under nitrogen and 6.63 g (0.038 mole)
of benzenesulfonyl chloride were injected. After stirring for 20
hours at 60.degree. C., the reaction was stopped by cooling the
flask to room temperature. No reaction occurred as evidenced by NMR
analysis.
(Comparative) Example 5
[0051] A 100 mL, 3-necked flask fitted with a magnetic stirrer, a
nitrogen inlet and a reflux condenser was charged with 5.80 g
(0.045 mole) of 2,2,4-trimethyl-1-oxa-2silacyclopentane. The flask
was heated to 50.degree. C. under nitrogen and 5.84 g (0.048 mole)
of allyl chloroformate were injected. After stirring for 17 hours
at 50.degree. C., the reaction was stopped by cooling the flask to
room temperature. No reaction occurred as evidenced by NMR
analysis.
(Comparative) Example 6
[0052] A 250 mL, 3-necked flask fitted with a magnetic stirrer, a
nitrogen inlet and a reflux condenser was charged with 32.60 g
(0.25 mole) of 2,2,4-trimethyl-1-oxa-2silacyclopentane. The flask
was heated to 40.degree. C. under nitrogen and 23.41 g (0.31 mole)
of allyl chloride were injected into the flask. After stirring for
21 hours at 40.degree. C., the reaction was stopped by cooling the
flask to room temperature. No reaction occurred as evidenced by NMR
analysis.
* * * * *