Note: Descriptions are shown in the official language in which they were submitted.
~.~3'~
This invention relates to the production of unsaturated
cyclic ethers of the type of di-alkenyl substituted tetrahydropyrans,
higher alcohols, ln particular Cg-alcohols, as well as other oxygenated
compounds from conjugated dienes and aldehydes, and to novel ;;
compositions of matter obtained by this process. ;
According to the present invention di-alkenyl
substituted tetrahydropyrans and unsaturated higher alcohols with
carbon numbers equal to the double amount of carbon atoms present in
the conjugated diolefin plus the amount present in the aldehyde ,
are produced by a process comprising contacting a conjugated diolefin ``
with an aldehyde in the presence of a salt or chelate or coordination
compound of Pd or Pt in their oxidation state +2 and a ligand of the
type YR3 or Y(OR)3 wherein Y is phosphorus or arsenic and ~ is an
alkyl group with l to 12 carbon atoms or an aryl or arylalkyl group
with an equivalent or higher amount of carbon atoms if the ligand is ~ ~-
not already present in the coordination compound. I
The conjugated diolefin rontains at least one grouping
- C= I - C= ~
in which the residual valencies on the carbon atoms may be satisfied '~
by hydrogen atoms or hydrocarbon residues or other substituents.
The hydrocarbon residues may comprise aliphatic or aromatic groups
and theother substituents may be of inorganic nature, such as
halogen atoms. Preferred examples of such conjugated diolefins
::
- 2 -
~379~
are butadiene, isoprene, and 2,3-dimethyl butadiene, that is
diolefins containing two terminal conjugated double bonds.
The aldehydes used in this process are preferably
aliphatic aldehydes containing 1 to 12 carbon atoms. They may be
substituted with functional groups like for example hydroxyl-groups,
formyl groups, acetyl groups or nitrogen containing groups.
They may also carry other heteroatoms like for example halogens.
Aromatic aldehydes may also be used.
Preferred are the lower aliphatic aldehydes and most preferred is
formaldehyde.
Also dialdehydes will undergo the reaction with the con~ugated
diolefins, such as glyoxal.
Any compound releasing the aldehydes cited above under the reaction ;~ `
conditions may be employed in place of these aldehydes. ;
Salts, chelates or coordination compounds of
,,~,:,;
palladium or platinum with the above mentioned ligands have been `- ;
. .~
found to be effective catalysts for the reaction in question. ;
The salts or chelates can be introduced into the reaction vessel
together with the ligand, with the advantage that no preformation
of the coordination compound is necessary. The coordination compounds
of Pd or Pt in their oxidation state +2 are based as already above
mentioned on complexes formed with ligands of the type YR3 or
Y(OR)3 whL:h may or may not have other sdditional ILgands.
., .
~ 3 ~
)37~
Representative structures are bis alkyl phosphine
as well as bis-aryl phosphine- coordinated Pd and Pt salts.
Preferred are salts, chelates or coordination compounds of palladium.
Any salt is in principle effective but good results are obtained
when using palladium acetate, nitrate, chloride or as a chelate
acetylacetonate or coordination compounds of the afore mentioned
salts with the ligands YR3 or Y~OR)3. These coordination compounds
or complexes may have different or additional ligands provided these
ligands can be replaced under the reaction conditions by the ligands
YR3 or Y(OR)3 and/or by the diolefins which are the reaction partners
as indicated above.
Generally the reaction produces as the major
product the cyclic ethers, and as the minor product alcohols in
amounts varying from less than 1 to more than 20 %. It may be
advantageous to have additionally free phosphines present in the
reaction mixture, even in the case when coordination compounds
are used containing already the phosphines. They exert a stabilizing
.,
effect on the catalyst system. On the other hand the reaction rates ~ b
increase with decreasing ratio of phosphines to Pd or Pt, resulting
also in a change Ln the product composition which then contains
higher amounts of Cg-alcohols. ~
Thus the ratio of metal to phosphines (and the other ligands described) `
will broadly lie in the range of 2:1 to 1:15. A ratio of 1:1 is
advanttgeout as de:cribed above,i increasing the reaction ra.e.
r :
' '
37g~1
The reaction is preferably carried out in the liquid
phase. Particularly the presence of water is advantageous for a
smooth reaction, but also other solvents preferably polar solvents
which enhance the miscibility of the reaction partners and water
improve the process.
The following list of solvents which should not
be considered restrictive shows examples of different classes of
solvents which have been successfully employed in the process of
this invention : methanol, isopropanolJ tetrahydrofuran, benzene, ;-~
dimethylsulfoxide, formamide, dimethylformamide and hexamethyl ~ ;
phosphoramide.
In case water is present emulsifiers may be employed. ~`
In case the anion of the palladium salt is the
conjugated base of a strong acid,but not only then,the additional
presence of a buffer or base, e.g., sodium acetate or sodium
carbonate is useful and may speed up the reaction.
The presence of C02 increases the amount of alcohols
in the reaction product.
The concentration in the reaction mixture of the salt
or chelate or coordination compound of Pd or Pt metal preferably
lies within the range O.OOOl to 0.05 molar, more preferably lies
within the range O.OOl to 0.02 molar.
The process according to the invention is carried out
at a temperature within the range of 0 to 200 C, preferably within
the range o~ 50 to 150 C and more preferab1y uithin the range oi
~ : '
.~ :~: . .. - ..
~ 037~
80 to 110 C. The molar ratio o~ conjugated diene to aldehyde is
broadly within the range 1:5 to 11:1.
The process according to the invention leads to
p~oducts which are composed of one or more isomers oE six membered
cyclic ethers which are doubly substituted with unsaturated side chains. ~-
In addition products are formed comprising primary and secondary
alcohols with carbon atoms equal to the double amount of carbon
atoms present in the conjugated diolefin plus the amount present
in the aldehyde.
The process according to the invention can be
considered as a simultaneous co-cyclotrimerization and co-trimer-
ization of aldehydes with conjugated diolefins. It could not be
expected from prior art processes of dimerizing conjugated diolefins
that such a combined co-cyclotrimerization and co-trimerization
reaction would occur.
The cyclic ethers can be generally represented
by the following chemical structure :
~'` ' '
R13 H R8 .-
R3 ~ \(2) D
C C--R~ C' C
Rl--C~ 3~/ R10 R9
R2 R5 R6 R12 Rll Type I Isomer
: :`
-- 6
:~
.,
.:: . . . , :.,-: . , : ,. : - .
~V379~1
wherein the Rl 13 substituents represent hydrogen, alkyl, aryl,
substituted alkyl, substituted aryl or halides, like chlorine
or other heteroatoms. They may be all equal, for instance hydrogen,
or different, for instance hydrogen, ~ethyl and ethyl groups.
The number of carbon atoms of the alkyl substituents may be `~
from 1 to 12, but preferably it is not higher than 4.
A second group of cyclic ethers, Type II isomer,
produced usually in a ratio of about 1:2 to 1:3 are isomers
of the Type I cyclic ethers~ which carry the alkylidene substituents -
on the carbon atoms C2 and C4 instead of C2 and C5.
It will be understood that the reaction is easier
to perform the less substituents are present. The ether structure
will of course be dependent on the type of substituents present
in the starting materials. If butadiene and formaldehyde are
reacted according to the process of the invention all the
substituents are hydrogen, the formula for the Type I isomer is
then
H H H
H~ C--\ D--H ~:
C C--H C, C
/ H
H -C~ H ~ H H H
.` ' '~:
, .',
- 7 -
.-- ~ .. . .; , : ,
~037a~
Similarly Lf isoprene and formaldehyde are reacted according to the
process of the invention the structure, in which R3 and R9 are equal
to CH3 and the other R'srepresent hydrogen, is as follows for the
Type I isomer.
. H H H
CH~~C--O~ C H
CC--H C C
D \ / H CH 3
H C~ &\ ~
H H H H H ~ .
Isomeric structures here also exist wherein R4 and Rlo or R4 and R
.or R3 and Rlo are methyl groups. Also stereoisomers are possible.
If acetaldehyde is one of the reactants the above~structures will
possess a methyl group represented by R13.
The same structures apply to the Type II isomer with the alkylidene
substituents in the 2,4 position.
-If the dialdehyde glyoxal is one of the reactants
and butadiene the other the following trifunctional cyclic ether
and its Type II isomer are the products, which are new compositions
of matter. CH-O H
H C--G C- - H
\c- c/~ \c--cD ;~ ~
H ~ C~ ~C, ,'~`
H H H h H
-- 8 --
: .
:
. - .; . . . .. .
`/` . : . . . , . ` . ` ` ,: ` ~ . ` . ` . -
~0379~
' , :~
The unsaturated cyclic ethers are useful as chemical
intermediates and polymerizable monomers.
The unsaturated cyclic ethers as represented by the above formulae
can be subjected to mild hydrogenation using suitable catalyst
systems, such as for instance the cat~lyst system which catalyses
the present reaction. A convenient way to carry out such a process
is by performing the present reaction for a time sufficient to
produce the cyclic ethers and then introducing hydrogen in the
reaction vessel.
The saturated cyclic ethers, which are novel
compounds can be represented by a similar structural formula
as the unsaturated ones, namely
. :
Rl3 H R8 ` `-
\ / \
'` \ / \ / ';;-,
H C--R4 C` C :
H/ \ / RlO
Rl--C\ C & R9
- R2 R5 R6 R12 Rll - ~:
. . .
- wherein the R substituents have the same meaning as above.
Corresponding formulae can be designated to the saturated cyclic
- ethers derived from butadiene and formaldehyde, isoprene and
- formaldehyde and butadiene or isoprene and acetaldehyde. ~;
Similar compounds ~re formed fr Type II isomers. Such saturated
cyclic ethers can be used as high boiling solvents. ~-~
~ ,:
~ _ 9 _
' ,'' ''
~ 37~
The unsaturated cyclic ethers can be oxidized to diepoxides and
diacids, wherein the epoxide groups and acid groups are attachcd
to the pyrane ring, which may be substituted.
They can also be converted to dialcohols by hydroformylation, the
alcohol groups becoming attached to the side chains. High temperature
hydrogenation will lead to ring opening to give among others primary
branched alcohols of the 2-ethyl heptanol type, which are useful
as plasticizer alcohols.
In the process of the invention also primary and
secondary unsaturated alcohols are produced in addition to the
cyclic ethers.
The general structure of these novel alcohols
which can be obtained by the process according to the invention
~ can be represented by the following formulas
R~
.~ R~ ~H-OH R R
~C C~R C - - C
R R R R R
: R CH-OH R R
C C--R R--C --C
~C~ C R
R R R R R R R
- 10 -
~7~
R CH-OH 1~ R
C--C--R C=C
R~C~ R/\R R/\R R/~
wherein the R's substituents represent hydrogen, alkyl, aryl,
- substituted alkyl, substituted aryl or halides, like chlorine or : ?~
other hetero atoms. They need not be equal.
More specifically in case the terminal carbon ;~
: atoms of the conjugated diolefins have only hydrogen the :
structures are as follows :
R
.. R~ ~H-OH R R ; ~ `
/ \H~ C--H :
~C~ H
. H H H H H H H ~`:H .:
- 11 - ~.
.-, . ~:
~Q37~
R~
R CH-OH F~ R
C C--R C=C
~C~ &\ / \ ~ \ H .;::
H H H H H H H H
- In case butadiene and formaldehyde are the reactants the following
three unsaturated primary alcohols which on hydrogenation give
all 2-ethyl heptanol, a potential plasticizer alcohol, are formed
besides the cyclic ethers.
J~ ~H2-OH H H
~C~ ~C~ ~C ~--H
H H H H H H
H CH2~H H~
~c~/ ~c~cf ~ H
i I H H H H H H ~ ~ :
.. ; ,
- 12 -
, ~''.
'' ' '''
~':
~379
H CH2~H H H
~C - C~H f - C 2-vinyl-5-heptenol
~C~ H
~ I H H tl H H t I H
The ethers and alcohols produced accor.ding to the process of the
invention can be isolated by means of gas-liquid chromatography
or distillation.
.
EXAMPLE 1 :
2.1 g (3 mmol) bis-triphenylphosphine palladium
dichloride, 2.4 g (9.15 mmoles) triphenylphosphine, 0.508 g
(6 mmoles) sodium-acetate and 110 g of 35 % solution of formal-
dehyde (1.29 moles) in water were placed into an autoclave and
]50 g (2.78 moles) butadiene added thereafter. The mixture
was heavily stirred and kept at 85 C for 20 h. After cooling
to room temperature the unreacted butadiene was vented.
The reaction product separated in two phases. 132 g (88 %) of
the originally charged butadiene was converted to organic
products. The organic layer weight was 180 g, the weight of ;
the water layer was 60 g. -~
- By G.L.C. it was shown that 40 % of the organic
layer consisted of two compounds (ratio about 2:1) which were
- shown by Nuclear Magnetic Resonance to be 2.5-divinyltetrahydropyran
[(multiplets centered around S 5.6 and ~ 5 (2 vinyl groups) as well
~ `:
'
_ 13 --
`
- -; : - .` . , - . .
~037~
as around ~3.8 and b 3.1 (3 protons in~ position to oxygen~
a slightly broad peak at c~2.1 (CH-C=C proton)and a multiplet
between ~ 1.9 (two CH2 groups~ and 2.4-divinyltetrahydro-
pyran ~multiplet centered around ~ 5.6 and ~5 (2 vinyl groups)
as well as around ~3.6 (3 protons in~< position to o~ygen);
a slightly broad peak centered at ~2.:L (CH-C=C proton) and a
multiplet between ~ 1.4 - 1.7 (two CH2 groups)~ .
Infrared spectrum and mass spectrum of both compounds were
identical. (Parent peak at m/e 138, base peak at m/e 54).
6 % of the organic layer was proved to consist
of doubly and triply unsaturated Cg alcohols of the following
structure.
A) 2 1 2 2 2 2
NMR : A multiplet between ~ 4.8 - ~6.1 ppm (two vinyl
groups); doublet at ~ 3.3 (CH2-0 grouping); OH protons
which shifts on dilution; broad three proton multiplet,
centered at ~2.1 (=C-CH2 and =C-CH-); multiplet ~ -
- between Sl.l and S 1.6 is due to the two remaining
methylene groups. ~
Mass Spectrometry : No parent peak but diagnostic `
peaks at m/e 122 (P-18); m/e 125 (P-15); m/e 109
(P-31); m/e 107 (P-33).
.` - '.
B) CH2 = CH - CH - CH2 - CH2 - CH = CH - C~1
CH OH
, ' ~' ' :
14
, ' ~", ~.
':
' `' .
NMR : Multiplet betw~en ~4.8 - S6.1 (vlnyl group) and
multiplet cencered around SS.4 (internal double bond
protons). Doublet at S3.3 (CH2-0 grouping~. Methyl
on double bond (doublet at Sl.6). Broad three protons
multiplet centered at $2.1 (CH2-C= and =C-CH-). Multiplet
between ~1.2 and ~ L.5 represents the remaining
methylene group. 0~ peak shifts on dilution.
Mass Spectrometry : The mass spectrum Is identical
with that of the above Cg isomer.
. .
C) CH2 = CH - IH - CH2 - CH = CH - CH = CH
::
NMR : Wide range of absorptions between S4.8 - ~6.7
(8 protons) indicate conjugated double bonds.
The doublet at S3.4 is due to the methylene group
adjacent to oxygen, The broad absorption between
~ 2 and S 2.5 is due to the =C-CH2 and =C-CH groupings.
The OH peak shifts on dilution. ~-~
:
Mass Spectrometry : No parent peak but diagnostic
peaks at m/e 120 (P-18); m/e 107 (P-31) and
m/e 105 (P-83).
EXAMPLE 2
0.68 g (3 mmoles) palladium acetate, 1.82 g (9 mmoles) ~ -~
tri-n-butylphosphine, 85 g of a 35 % solution of formaldehyde (1 mole)
in water were placed into an autoclave and 334 g (6.2 moles) butadiene
added thereafter.
:'
,.
~, ~
:~V;~79~
The mixture was heavily stirred and kept at 35 C
for 3 hours. After cooling and venting the unreacted butadiene,
223 g of a greenish-yellow organic phase was separated from the two
phase reaction product. Flash distillation under reduced pressure
gave 211 g of organic product, which was found to contain 48.7 %
of a mixture of 2.5- and 2.4-divinyl-tetrahydropyran and 20 % of
1.3.7 -octatriene along with less than 1 % of C9-alcohols.
- '
EXAMPLE 3 :
0.17 g (0.75 mmoles) palladium acetate, 0.20 g
(0.75 mmoles) triphenylphosphine, 42.5 g of a 35 /0 solution of
formaldehyde in water (0.5 moles~ and 162 g (3 moles) of butadiene ~ -
were charged to an autoclave and heated to 85 C under heavy stirring
for 40 minutes.
The 66.8 g of organic product were shown to
contain in addition to some by-products 13.7 % 1.3.7-octatriene, ~-
34.2 % divinyltetrahydropyrans and 25.1 % unsaturated C9-alcohols.
,
EXoMPLE 4 :
0.23 g (0.75 mmoles) palladium acetylacetonate,
0.20 g (0.75 mmoles) triphenylphosphine, 42.5 g of a 35 % solution
of formaldehyde in water (0.5 moles) and 165 g (3.05 moles)
of butadiene were charged to an autoclave and heated under heavy
- stirring to 85 C for 1 hour. The organic layer of the reaction
product was analysed by GLC and found to contain, besides some -
other unidentified products, 10.7 % 1.3.7-octatriene, ~
"' ; ':'
- 16 -
`','
. . . . .. . . . .. - .. ,.. ,, ,.. . .:- . . .,-.. ... -: ; - :
.. :- . . . ... . .
iV379~
33.9 % divinyl-tetra~ydropyrans and 21.6 ~/~ unsaturated Cg-alcohols. ;~
EXAMPLE 5:
0.34 g (1.5 mmoles) palladium acetate, 4.6 gj;
(14.7 nnnoles) triphenylarsine, 42.5 g of a 35 % water solution o~-
formaldehyde (0.5 mole) and 172 g (3.18 moles) of butadiene were
charged to an autoclave and heated to 85 C under heavy stirring for
3 hours.
22.5 g of organic product were obtained. Its com-
position after flash distillation was shown to be, besides some side ;'
products, 5.2 % octatriene, 28 % divinyl tetrahydropyrans and 42 %
Cg alcohols.
EXAMPLE 6:
2.37 g (3 mmoles) PtC12 (PPh3)2, 2.4 g (9 mmoles)triphenylphosphine, 2.54 g (18.5 mmoles) sodiumacetate-hydrate,
85.5 g of a solution of formaldehyde (1 mole) in water and 324 g
(6 moles) butadiene were charged to an autoclave and heated to
85 C under heavy stirring for 3 hours. Then 10 g organic product
could be separated from the unreacted formaldehyde-water layer.
GLC analysis showed that this product contained besides some
other unidentified products the following compounds: 6.8 ~O
octatriene, 56.4 % divinyl tetrahydropyrans and 2 % unsaturated
Cg-alcohols.
::
,:
- 17 - ~
~ ' ~
,
EX~`~LE 7 ~ 7~
The butadiene of Example 1 was replaced by 280 ml
(180 g, 2.8 moles) isoprene, all other conditions belng the same.
A mixture of four isomers of the expected cyclic ether, namely
2.5-diisopropenyltetrahydropyran, 2-isopropenyl-5-vinyl-5-methyl
tetrahydropyran, 5-isopropenyl-2-vinyl-2-methyl-tetrahydropyran,
and 2.5-divinyl-2.5-dimethyltetrahydropyran was formed as the major
product as was shown by mass-spectrometry and nuclear magnetic
resonance. Similar type II isomers are also present in minor amounts.
.- :
EXAMPLE 8 :
2.1 g (3 mmoles) bis-triphenyl phosphine palladium-
dichloride, 2.4 g (9.15 mmoles) triphenyl phosphine, 0.508 (6 mmoles)
sodium acetate, 60 ml of degased watar, and 65.5 g acetaldehyde
(1.5 moles) were placed into an autoclave and 138 g (2.56 moles)
butadiene added thereafter. After 20 h at 85 C a weight increuse
from reacted butadiene of 24.4 g (17.5 %) was found. 9.6 % of the
organic layer (weighing 57.3 g) was shown by mass-spectroscopy,
to be 2.5 divinyl-6-methyl tetrahydropyran
EXAMPLE 9
0.34 g (1.5 mmoles) palladium acetate, 1.57 g
(6 mmoles) triphenylphosphine, 36.2 g glyoxal (40 % solution in
. . .
water, 250 mmoles) and 162 g (3 moles) butadiene were charged
to an autoclave and heated for 1 hour and 50 minutes under heavy
stirring to 85 C.
- 18 -
:- -
~ 7~
The crude reaction product contained 70 g of ratherviscous organic material. It was shown by GLC analysis and by NMR
spectroscopy to consist among others of 1.3.7-octatriene, 2.7~
octadienol and 6-formyl-2.5-divinyl-tetrahydropyran `~
CH0 H
C/H \C~
H - -- C ~
H H H H H - -
NMR : Doublet at S 9.2 (aldehyde proton); multiplets
- centered around ~5 and S5.6 (2 vinyl groups) and ~'
multiplet between S3.4 and 54 (protonsin ~ position ~ ~ ~
to oxygen). ~lultiplet between ~ 1.2 and ~ 2.3 is due ~ ,
to CH~ CH2 groups-
Mass Spectrometry : Parent peak is at m/e 166,
.~ .
base peak at m/e 54. The important fragment at
m/e 137 is formed by loss of CH0 group.
i. ~
EXAMPLE 10 : ~ -
In an experiment which otherwise was carried out ~ -
exactly in the same way as example 1 after 20 h of reaction time the
unreacted butadiene was vented after cooling to room temperature.~
Then 102 atm. of hydrogen were pressed in the reactor, 57 atm of which
were absorbed within 150 min.
, . i ~ ,
Calculated on butadiene charged a yield of 67 %
of a virtually completely saturated oxygenated hydrocarbon mixture
was obtained.
The products which were separated represented the hydrogenation products
of the compounds obtained in Example 1.
- 19~
~Q379~
~- By GLC, mass-spectrometry~ nuelear magnetie resonance
most of the prod-let was shown to be 2.5 and 2.4 diethyltetrahydropyran. `~
It was aeeompanied by saturated Cg aleohols. :
. ` '.;,, .
'~ '
~, ~
- 2 ~ ~
.::
:
- ~ .
.` .~, ~
..,,,`,.".,., ~.....
i;,,.-. . .:
. . .~ `
:,`. :
: ` ',
".' . ~,
- "~
:' 'j ~ ~ -
, "`''~ :
.. ,'~ ~: '
