Note: Descriptions are shown in the official language in which they were submitted.
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H013C~IST A~CTIENGESELhSCHAFT HOE 93/F 909 Dr.GL-nu
Werk Gendor~
Proaeæs for the preparation of tertiary dialkylpoly-
hydroxy-amines
Description
Tertiary dialkylpolyhydroxy-amines, in particular in the
i form of dialkylglycamines such as dimethylglucamina, are
compounds which are valuable, for example, a~ an additive
to wetting agents and cleaning agents, to plasticizers,
and to slip additi~es and lubricant~ and the like. In
accordance with US Patent 2,016,962, they are prepared by
reacting a reduaing sugar such as gluco3e, fructose,
lactose or xylose with a dialkylamine under hydrogenating
condition~. The specific procedure i~ to react a sugar
compound with a dialkylamine in water as ~ol~ent and in
the presence o~ a supported ~ickel cataly~k at a hydrogen
pres~ure of at lea~t 15 bar and a t~mperature of from 80
to 125C, to give the dialkylpolyhydroxy-amine. This
process ~i.e. the reductive alkylation of ~ugar compounds
with a dial~ylamine~ haa been known for a long time and
ha~ the disadvantage that the tertiary ~ugar amine iR
generally obtained in a low yield.
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The linear dialkylpolyhydroxy-amines under di~cussion,
e~pecially in the form of dialkylglycamines or dialkyl-
glucamines, have become o~ increasing importance inrecent time~, sinca they are biodegradable and can be
obtained from sugar a~ a regener~tive raw material. There
i3 therefore a more pressing requirement for a process by
which the~e amino alcohols are obtained in a high yiald
~`~ 30 and purity. The present invantion provides such a
process.
The proce~s according to the in~ention for the prepara-
tio~ of a tertiary dialkylpolyhydroxy-amine comprises
reacting a secondary N-monoalkylpolyhydroxy-amine with an
aldeh~de in a molar ratio of 1 : from 0.90 to 1.5,
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;, pre~erably 1 : from 1.03 to 1.1, in water as sol~ent and
in the presence of a metallic hydrogenation c~talyst at
a hydrogen pressure o~ from 10 to 150 bar, pra~erably
~rom 30 to 100 bar, and at a temperature of from 70 to
150C, preferably from 80 to 130C, to give the tertiary
dialkylpolyhydroxy-amine.
In a preferred proce~ure~ the reaction is carried out in
two steps in which
a~ a secondary N-monoalkylpolyhydroxy-amine i~ ~irst
reacted with an aldehyde in a molar ratio of
1 : from 0.90 to 1.5, preferably 1 : from 1.03 to
1.1, in water as sol~e~t at a temperature of from 15
to 60C, preferably from 20 to 40C, and at atmo~-
pheric pres~ure to give the N-monoalkylpolyhydroxy-
~ 15 amine/aldehyde adduct, and
i b) the rsaction product obtained in step a) (essen-
tially compri~ing the adduct formed and water) is
hydrogenated in the presence of a metallic hydro-
genation catalyst with hydrogen at a pressure of
from 10 to 150 bar, preferably from 30 to 100 bar,
and at a temperature of from 70 to 150C, preferably
from 80 to 130C, to give the tertiary dialkylpoly-
hydroxy-amine.
~he water, as solvent, i8 generally ~mployed in an amo~nt
such that a from 5 to 60% strength by weight solution
ia preseut, preferably a from 15 to 40% ~trength by
w~ight solution, bas~d on the quantity of N-monoalkyl-
¦ polyhydroxy-amine employed. The ~tated amount of water
include~ water introduced by, for example, using formal-
dehyde in the form- of a preferably from 30 to 40%
strength by we~ght aqueou~ solution. The metallic hydro-
genation catalyst i8 preferably a palladium, platinum
and/or nickel catalyst, with nickel catalysts being
preferred. The hydrogenation catalyst can be employed as
a ~upported catalyst, powder catalyst or Raney ~ickel
catalyst. Raney nickal catalysts are preferred. The
hydrogenatlon cataly~t i~ generally employed in an amount
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~ of from 0.1 to 10% by weight, preferably in an amount of
j from 0.5 to 5% by weight, based on N-monoalkylpoly-
¦ hydroxy-ami~e Ifor clarity, the weight perce~tages stated
~ relate to the metal alo~e and thus do not also COMpriSe,
-' 5 for example, the support material).
Specifically, the reaction according to the invention i
pref~rably carried out by heating the N-monoalkylpoly-
hydroxy-amine and water at atmospheric pressure to ~rom
j 15 to 60C, preferably from 20 to 40~. The aldehyde
;¦ 10 compound i8 then added to this solution, continuously or
in portions, while stirring and maintaining the stated
¦ temperature, a~d the mixture is then allowed to react to
completion (adduct ~orma~ion) at from 15 to 60C, prefer-
ably from 20 to 40C (0.5 to 2 hour~0 The resulting
reaction product, essentially compri~ing th2 adduct
~ormed and water, i then subjected to hydrogenation. For
thi~ purpose it is charged, together with the-hydroge~a-
tion catalyst, while ~tirring, at a temperature of from
70 to 150C, preferably 80 to 130C, with hydrogen up to
a pre~sure of ~rom 10 to 150 bar, preferably from 30 to
100 bar. This hydrogen pre~surQ i~ maintained at tha
stated temperature and while stirring u~til no further
hydrogen i8 taken up, which generally takes from 1 to
5 hour3 including any after-reaction. The re ulting
reaction product essentially compris2s the desired
tertiary dialkylpolyhydroxy-amine and water. If it is
desired to isolate the tertiary amine compound ~rom the
aqueous solution, then the catalyst and the water will be
separated, thu~ gi~ing the tertiary amine compound, if
30 j desirQd by recrystallization ~rom a ~uitable sol~ent ~uch
as isopropanol. The separation mentioned can be carried
out by, for example, filtering and stripping or
distillation.
..
The proces~ according to the invention provides the
tertiary dialkylpolyhydroxy-amines in a high yield and
purity. It can be carried out either continuou~ly or
batchwi~.
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The following comments apply with regard to the starting
compound~: the aldehyde compound is preferably an alipha-
~ic aldehyde, for example formaldehyde or acstaldehyde,
with ~ormaldehyde being preferred. Formald~hyde is
preferably employed in the form of a Erom 30 to 40%
strength by weight aqueous Qolution. The N-monoalk~1-
, polyhydroxy-amine, often ~i~nply termed a secondary
j polyhydroxy-amine, i8 pre~erably of the following formula
(1)
. 10 R~ z ( 1 )
1 in which R1 i8 a C1 to C18 alkyl, preferably C1 to C6 alkyl
J~ or Cl to C6 hydroxyalkyl ~uch a~ 2-hydxoxyathyl or
2-hydroxypropyl, a~d iR particularly pre~erably methyl
or ethyl, and Z i~ a polyhydro~y hydrocarbon radical
having a linear hydrocarbon chain with at least 3 OH
group~ or an alkoxylat2d derivati~e thereo~, preferably
an ethoxylated and/or propoxylated derivati~e. Z i~
pr~erab1y the radical of a mono-, oligo- or polysac-
charide compound which is connected to the nitrogen atom
via a methylene group. Z i8 particularly preferably a
group of the formula -CH2-CH(OH)~-CH~OH, in which n is an
integer from 3 to 5, preferably 3 or 4 and particularly
preferably 4. Ths ~tarting compounds of the ~ormula ll)
are known and are commercially available. ~-
i 25 The tertiary polyhydroxy-amines prepared by the process
according to the in~e~tion are consequently of the
¦ following formula (2
Rl
N-Z (2?
in which R1 a~d Z have the meanings gi~en and R2 i8 the
substituent introduc~d by the aldehyde co~pound. It
follows from the above statement~ that the di-C1 to
C6-alkylglycamine~ are the pre~erred compounds, with the
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glucamine compounds ~uch as dimethylglucamine, diethyl-
i glucamine and ethylmethylgluca~ine being particularly :~
i3 preferred. .
The invention is now described in more detail using
examples.
Example 1
' .
; 288.7 g of a 36.5~ atrength by weight aqueous ~o~m-
j aldehyde solution are metered into 1500 g of a 43%
~3 strength by weight aqueous N-methylglucami~e solution
10 (ami~e No. 22.3) ~t about 15C. The mixture i8 ~tirred at
~: about 15C for 1 hour and then 2R g of Ra~ey nickel are
3 added, and the mixture i8 hydrogenated at 100C a~d
~! 30 bar hydrogen pressure.
.
Yield of N,N-dimethylglucamine: 98.2~; m~lting point:
90C.
¦ Example 2
'
288.7 g of a 36.5% s~rength by weight aqueous form-
. ~ aldehyde solution are metered into 1500 g o~ a 43%
strength by weight aqueous N-methylglucamine solution
: 20 (amine No. 22.3) at about 35C, and directly after the
: additio~ has been completed the mixture is admixed with
28 g o~ Raney nickel and hydrogenatéd at 100C and 30 bar
hydrogen preasure.
Yield of N,N-dimethylglucamine: 98.1%; melting poi~t:
25 89C. . `:
: .:
Example 3
288.7 g o~ a 36.5~ strength by weight aqueous ~orm-
aldehyde solution are metered into 1500 g o a 43%
JI stre~gth by wPight a~ueous N-methylglucamine solution
J 30 (amine No. 22.3) at about 35C. The mixture is sti~red at
1.
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about 35C for 1 hour and then 28 g of Ran~y ~ickel are
added, and the mi~tuxe i~ hydrogenated at 130C and
100 bar hydrogen pressure.
Yield of N,N-dimethylglucami~e: 97.8%; meltiny point:
90C.
Example 4
132 g o~ a 36.5% ~trength by weight aqueous ~ormaldehyde
~olution are metexed into a mixture of 689 g of a 43%
~trength by weight aqueou~ N-methylglucami~e ~olution
(amine No. 22.3) and 811 g of additional water at about
35C. The mixture i8 stirred at about 35C $or 1 hour and
the~ 28 g o~ Raney ~ickel are added, and the mixture is
hydrogenated at 100C and 30 bar hydrogen pres~ure.
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i Yield of N,N-dimethylglucamine: 97.8%; melti~g point:
99C.
Exampls 5
288.7 g o~ a 36.5~ strength by weight aqueous ~orm-
aldehyde ~olution are metered into 1500 g of a 43%
strength by weight aqueous N-mathylglucamine ~olution
1 20 (amine No. 22.3) at 60C. The mixture is ~tirred at about
¦ 60~ ~or 1 hour and then 28 g o~ Raney niakel ar~ added,
and the mixture i8 hydrogenated at 100C and 30 bar
hydrogen pressure.
Yield of N,N-dimethylglucamine: 98.4%; melting point:
9~~
~xample 6
40 g of N-butylglucamine (amine No. 41.9) are ~u~pended
in 60 g o~ water. 1~. 8 g of a 36.5% ~trength by weight
aqueous formaldeh~de ~olu~ion are added to th~ ~uspen~io~
at about 25C. A clear solution i~ ~ormed which i~
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'~ stirred for a further 1 hour at about 25C. 1.7 g o~
~ Raney nickel i~ then added to the ~olution, a~d the :~
i mixture i~ hydrogenated at 100C and 30 bar hydrogen
pr2. ~ure.
5 Yield o~ N-meth~l-N-butylgluc~ine: 99.3%; melting point: .
52C.
. .
¦ Example 7
';
40 g of N-hexylglucamine (amil~e No. 37.93 are ~uspended
in 60 g o water. 13.1 g of a 36.5% strength by weight :.
aqueou~ formaldehyde olution are added to the ~uspen~ion
at 25C. A claar ~olution i8 formed w~iah i8 ~tirred for ..
I a further 1 hour at 25C. 1.9 g of Raney nickel i8 then
added to the ~olution, and the mixture i~ hydrogenated at
- 100C and 30 bar h~drogen pressure.
Yield of N-methyl-N-hexylglucamine: 99.2%; melting point:
74C.
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