Note: Descriptions are shown in the official language in which they were submitted.
~3~)9~
The present i~ve~ io~ relates to novel phtbalic acid derivatives, and
to a process fc,r ~heir preparation. The nov~l compounds Are used for
the prep~ration of silicon-modified phtha]ic acid derivatiYes whi~h
can be used as adhesion promoters.
The literature cliscloses that various si]anes, for example vinyltri-
chlorosilane, vinyl-tris-(2-methoxy)-silane and y-aminopropyltrietho~y~
silane) may be used as adhesion promoters for various applications,
for example for the production of glass fibre-reinforced plastics,
for scalants, for lacquers and for adhesives [compare, fo~ example, ;~
Defazet, 28, 207-211 ~1974) and Kunststoffe, _ , 909-912 (1965)].
HGwever, the properties of the products obtained using these known
adhesion p~omoters in part leave something to be desired, especially
; in respect of water absorption, resistance to thermal oxidation and/or
electrical properties.
It is the object of the present invention to provide novel inter
mediates for the preparation of adhesion promoters, by means of which
the a~ove disadvantages may be avoided.
The novel phthalic acid derivatives correspond to the formula I
. ~ ~ /
il i ~
~ CO-R 1I)
~-C~2-C~l=
in which Rl and R2 independently of one another are alkoxy with 1-12 C
atoms or phenoxy or Rl and R2 together are the -0- group and R3 is
alkyl with 2-7 C atoms, cycloalkyl with 5-7 C atoms or benzyl.
The compounds of the form~la I may be prepared by a method wherein
a compound of the formula II
., .
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;
O-Rl :~
Il i (II)
\CO-P~2
NH-R3
~.
~ which Rl, ~2 and R3 have ~he above meaning, is reacted wi~h an
`~ allyl halide~ esp~cially allyL bromide or allyl chloride, preferably
in the presence oE a base, for example an alkali metal carbonate or
alkali metaL hydroxide, ~or example potassium carbonate, potassium
hydroxide or sodiu~ hydroÆide.
The above reactiol~ ui~.h allyl halide is advantageo-lsly carried out
~ in a polar medium, especially ln an aqueous medium, at temperatures
`~ bet~een a~ou~0C and 100C, especially ~etween about 25C and 80C.
;~ ~he compounds of the formula II are kno~n~and may be prepared by methods known~per ~se.
AIkoxy troups~RI~and or R2 and _lkyl aro~ps~R~may " seralght-chaln
~-~ or brar~chedO ~s~examples of aIkoxy~or alkyl groups according to the
defiDition the~e may be mentioned~the methoxy, ethoxy, n-propoxy,
isopropo~y, n-hexylo~Æyj~n-decyloxy and n-dodecyloxy group and the
methyl, ethyl, n-propyl, isopropyi 7 n-bu~yl, tert.-butyl~ n-pentyl,
n-he~yl and n-hep~yl ~roup. ~-
Rl and R2 are preferably alkoxy with 1-4 C atoms, especially methoxy
or ethoxy. Compounds where Rl and R2 together are the -0- group are,
however, very particularly preferred.
~- :
~ ~here R3 is an a1kyl~group, ;t is especially an~alkyl group with 2-4 5
; ~ Atoms and more particularly the ethyi or ~isopropyl group. ;~
: -
,.:
~:
.
- . ~ . ~ :
,
1~.37~
., .
-- 3 --
Where R3 is a cycloalkyl group, it is, for ~xample, the cyclopentyl
group and especi.ally the cyclohexyl group.
As men,ioned, the compo~mds o~ the formula I are valuable inter~ediates
for the preparation or silicon-modi.fied phthalic acid derivatives
adhesion promoters.
The silicon-modified phthalic acid derivatives may be prepared by
reacting a compound of the formula I with a silane.
~'
The reactlon is advantageously carried Ollt in an anhydrous organic ~ :
medium and in the presence of a catalys~. Examples of catalysts which
may be used are organic peroxides, such as tert.--butyl tiydroperoxide~ :
di-tert.-butyl peroxide:, peracetic acid, benzoyl peroxide, diacyl
peroxides and cumene hydroperoxide, or platinum or palladium catalysts,
for instance platinan~charcoal ca~alysts or P~.C16H2 ca~.alyst.
Examples of suitable inert organic solvents are aromatic hydrocarbons3
for instance benzene, t`oluene and:xylenes, cyclic ethers, for instance
tetrahydrofuran, te~rahydropyran and dioxane, and ethylene glycol
~onoalkyl ethers and dialkyl ethers each wi.~h 1-4 C atoms in the alkyl
portions, for ins~ance ethylene glycol monomethyl ether, monoethyl
ether, diethyl ether and di-n-butyl ether.
The reaction is advantageously carried Ollt u-nder a protecti~e gas,
for example ni~.rogen~or argon.
:
: The reaction temperatures are in general approximately between 80C
.;~
and 150C.
After completion of the reaction3 the solvent a~.d any excess silylating
~:~ agent present are removed in the conventional manner, for example
- by distilling off in vacuo.
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-- 4 --
Tlle silicon-modiEied ~h~halic ~cid derivatives are valua~le adhesion
promoters, es~ecially between inorganic solids and organic res;ns,
and may be used for a large number of applications ln the adhesives
industry and in the lacquer-using a~-d plast LC.5 proce9sing industries .
Example l
3-N-Ethyl-N-allylaminophthalic anhydride
21~.1 g (1 mol) of 3--nitrophthalic acid are dissolved in 17200 ml of
dioxane and hydrogenated at 20-25C, using 10 g of a palladium/
charcoal catalyst (5% by weight of palladium). 89 g (2 mols~ of freshly
distilled acetaldehyde in 300 ml of dioxane are then added and the
hydrogenation is cont;nued The catalyst is then removed and th&
reaction solution is evaporated i.n vacuo. The residue is repeatedly
extracted wi~h hot toluene and the sollltions are filtered and then
cooled until they crystall;se. 82.4 g (43,', oE theory) of 3-N-ethyl-
aminophthalic anhydride, melting point 133-134G9 are obtained.
Analysis for CloHgN03
calculated: C 62.82% H 4.75% N 7.33%
found: C 62.8 % H 4.8 % N 7.4 %
. ~
19.1 g (Ool mal) of 3-N~ethylaminop'nthalic anhydride and 13.8 g
~0.1 mol~ of potassium carbo~ate are dissolved in lS0 ml of water
whilst heating to 100C, with stirring. After the s~olution has cooled,
13.3 g (0.11 mol) of allyl bromide are added dropwise, whereupon the
mixture is again heated to 100C, in the course oE 3 hours. It is
then cooled to 20-25C, a further 3.5 g of potassium carbonate are
added, the mixture is~again heated to 100C alld a further 3.5 g of
allyl bromide are added dropwise. After sti}ring for 1 hour, the
solution is cooled (its pH is 7-8) and is acidified to pH 3-4 with
concentrated hydrochloric acid. It is then evaporated to dryness and
the residue is hea~ed to 160~C in ~he course of I hour. The crude
~L37~
product is repea~edly extracted with hot cyclohexane. A~ter removing
the solven~, 12 g (52% of theory) of 3-N-ethyl-N-allylaminophthalic
anhydride, melting point 80-83C, are obtained.
Analysis or C13~l4N3~
calculated: C 67.23~ H 6.08% N 6.03%
ound: C 67.352 H 6.02~ N 5.94%.
.
106 g (6.5 mols) of 4-nitroph~halic acid are dissolved in l~O~G ml of ~ ~;
dioxane and hydrogenated at 20-25C, using 10 g of a palladiumf
charcoal cat.~lyst ~5% by weight o palladium). 68 ml (55 g ~ 0.75 mol)
of butyraldehyde are then added and the hydrogenation is continued.
The cataly~t is then removed and ~he reaction solution is evaporated
in vacuo. 29,6 g (0.125 mol) of the residue (crude 4-N-butyl-amino-
ph halic acid) snd 17.5 ~ (0.125 mol) o~ K carbonate are dissolved in
125 ml o H~0. 18.1 g (O.lS mol) o$ allyl bromide ar~ added to ~he
solu~ion at 20C to 25~C and the reaction mix~ure is stirred for
,; , .
Z0 hou~s a~ 10C and then or 4 h~urs a~ 80C. The 4-~N-butyl-N - `
~llyl)-a~inophthal~c acid i8 prQ~ipita~ed a~ a da~k yellow oil ~y
~ddi~g 35% hydFocl~loric acidt ~ c~u~e ~roduct i~ ~aken up in ~hyl
aceta~e, ~he sol~tion i~ washed wi~h water and dried, and the acld is
h~ cycli~ed thermally or chemically to 4-(N~butyl-N -allyl)-amino-
phthalic anhydride. 17 g (52% of theory) o a dark yellow oil are
obtained.
:
The chemical cyclisation iB carried out as de~cribed b low: 33 ml
(0.4 mol~ of acetic anhydride are added to 0.25 mol of the ubove
acid and the mixture is stirred for 1 hour at 80-90C. The excess
acetic anhydride i9 then distilled off in vacuo. The oily re~idue
is taken up in a solvent mixture of diethyl ether and hexane, 30 g
:
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of silica gel are added and ~h~ mixtllre i9 fil~ered. After stripping
of the solvent, an oily product is obtained. Crude yield: 35 g (80%).
The material is ~hen Eractionated by r~lolecula~ patll distillatiorl, with
addition of Cu powder. 4-(N-~utyl-N-allyl)-aminophthallc anhydride is
obtalned in 50% yiel& as an oily prcduct of boilirlg point 1~5-190C/
-2
lQ n~l Hg.
Use Exa~lple
.
Iil a sulphonation flask, 1~.7 g (0.08 ml) of 3~N-ethyl-N-allylamino-
phthalic anhydride are dissolved in 300 ml of anhydrous toluene, under
nitrogen, and the solutioll is heated to 105C. At this temperature,
25~6 g (Q.124 mol) of tri-n-propoxys lane and 0.6 ml of an 0.02 molar
solution of hexachloroplatinic aci-l in propanol are added dropwise
in ~he course of 45 minutes, with stirring. The mixture is ~hen stirred
for a furth~ 3 hours at 110C. Aft~r e~-apora~ g off ~he solvent?
the residue is distilled in a high tacuum. 24.5 g ~70% of theory~ o
3-N-ethyl-N-(tri-n-propoxy)-silyl-propyl~minophthalic anhydride are
obtained in the form of a pale yellow oil~ boiling point 190~215C/
-3
mm~Hg.
Analysis for C22H35N06Si (~lecular weigh~ 438j
calculated: C 60.38% H 8.06% N 3.20% Si 6.42%
found: C 6006 % H 8.1 % N 3.4 % Si 6.4 %.
'
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