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CI mass spectra and the oxidation products of dobutamine under storing conditions
483
International Journal of Mass Spectrometry and Zen Physics, 47 (1983) 483-486 Elsevier Scientific Publishing Company, Amsterdam - Printed in The Netherlands
EI/CI
MASS
SPECTRA
AND
THE
OXIDATION
PRODUCTS
OF DOBUTAMINE
UNDER
STORING
CONDITIONS
K. PIHLAJA
and A. M8TTBNEN
Laboratory
for Physical
Chemistry,
University
of Turku,
SF-20500
50,
Turku
Finland
ABSTRACT Dobutanine dissolved in different water and alcohol solutions produced a black precipitate at a rate dependent on the amount of dissolved oxygen. The C precipitate ia shown to consist mainly of compounds :;: (m/z 313) both with a ketimine function in &?%:P&ZZ::: and with a different quinonoid structure at the catechol end.
INTRODUCTION When were
storing
found
on the
dobutsmine
to become
amount
(A) in different
red and the rate
of dissolved
water
of this
and alcohol
change
solutions
of colour
to be
they
dependent
oxygen.
1
HO
HO If the
solutions
observed five
times
further
the
In addition high
were
whereas faster
than
solution
to
carefully
an oxygenated
degassed water
an untreated
became
dark
(EI) resolution
mass
of the
and
a black
When
the red
began
a thorough were
formation colour
the reaction
material
studies
reaction
no colour
developed
analyses
spectrometric
oxidation
nitrogen
solution.
TR-, IJV- and elemental
characterization
with
solution
was
about
proceeded
to precipitate.
low
(CT/ET]
necessary
and of its major
and
for a conclusive
proaucts.
RESULTS 11.25
was
g of 1 in 450 cm3 of water
covered
by
red and within about
3 days.
filtration, repeated always
an aluminiun a day After
washed
5 times back
folio.
it became 7 days
with
with
the black
same
to 450 cm3 after
0020-73S~/S3/0000-0000/$03.00
browngray
distilled
the
was kept After
precipitate
water
original
the
and thick.
and ether solution
the filtrations. 0
at 336 K for 7 days.
2 hours
was
solution
The
decanter
changed
The precipitation separated
and dried. adjusting
Before
had
began
in
through
The
procedure
its total
placing
light
volume
at 336 K the
1983 Elsetier Scientific Publishing Company
was
solution way
was
ll.25
The
were
obtained
(3:l v/v
which
the
The
Akademi.
was
resolution
EI mass
of the
a Pasteur-pipet. in 37
precipitate
(1:l v/v),
CI
W-
elemental
accurate
methanol
days.
and
In this Similar
in methanol-
and low resolution
solid
DX-300
7035
GC/MS
composition
number
the
(Jeol
Ltd MM in some
IR-,
on a LKP-9000
Hence
spectrometry
programmed
(MM 7035)
the
precipitate.
and VG Analytical
by
obtained
(especially
in the
or NH3
through
black
water
analyzed
were
determination
to be difficult
temperature
10 minutes
g of the
in ethanol
first
latter
impurities
Bremen
0.55
for
+ 1 % KOH by weight).
precipitate
from
oxygenated
g of ;3 yielded
products -water
always
in Tokyo,
in Manchester)
cases),
B/E
linked
by burning
turned
was
because
of
some
by
high
MAT-212
direct
and
out
reexamined
Finnigan
using scan
spectra
in _&bo
of hydrogens) product
mass
instrument
inlet
isobutane
in (also
(DX-300)
spectra.
DISCUSSION Simple
model
structures
reactions
from
(2, ref.
1) suggest
an initial
formation
of quinonoid
1:
k 2b Dehydrogenation hydrogen
of a secondary
acceptor
R1CH2CH2NHCH(
(ref.
amine
can
also
be
effected
by
an
(organic)
2): = C(CH3]CH2CH2R2
CH3)CH2CH2Rz
NCH(CH3)CH2CH2R2
RI=
Ho
0 0
HO
or its
oxidation
product
$
=
OH
485
Probably
an immediate
quinonoid
precipitation
and ketimine
structures
after saves
the
the
consequtive
latter
from
formation further
of the
reactions.
. Already
the
oxidation related
to this
the
quinonoid
and
4).
The
high
inlet
the
EI mass
(2) but
it was
resolution
the
former
out
evaporates
was,
that
that
m/z
313
pattern
however,
already
using
temperature
297 and m/z
compositions
of C ,gH1gNC3W
nuch
B/E
faster.
m/z
is a molecular
to see how m/z
fragmentation
especially
clearly
elemental
showed
difficult
the
functions
experiments
pointed
with
spectra
rather
ion. From
molecular
and ketimine
system
products which
low resolution
product
linked
297 can be
the
existence
evident
(refs.
programmed
313 are two
showed
3
direct
separate
and C18H19N04(A)
scans
of
from
that.
3
-CHhCH=NXIH-CH2i.
Or
0
m/z
192
from 148
4
and m/z
the M*',
m/z
from M+',
m/z
first
significant
165
w
or
-CH,-N
and
in a lesser
313 and m/z 297. These losses.
=c;CH i.
177 and ions were
The both
2-
extent again
m/z
>
C18H19N04 m/z 313
products
-C10H120
m/z
come 282
EI scan
from m/z
and m/z as the
313 are
+
f
I
148
C17H16N04 m/z 298
C10H10N03 m/z 192
-
extent
on the normal
primary
-CH3-
+-
and m/z
in a lesser
apparent
major
298
(2.1
> C8H7N03+ m/z
11-j
165
-C8H7N03'
+ +C10H120 m/z 148
(2.1
due
486
to
rupture
a bond
accompanied shows from m/z
adjacent
by a simultaneous
for instance the
ions m/z
107
to the
ions m/z
hydrogen m/z
164,
192 and m/z
is characteristic
C=N bond
transfer
137,
in the (ref.
136
m/z
through
165
which
of m/z
4). Further
and m/z
consequtive
for the phenolic
case
fragmentation
which
109
of CO
losses
end of the molecules
is
165
are formed (ref.
3).
(2 and 2).
-CH3' +' C18H19N03 m/z
+
I The primary bond
to ions m/z
the
indicative
m/z
298
the
ions
149,
for
ketimine
+
( C9HloNO)
148
298
its amount mass
decomposition
and m/z
CI-spectra
from h are again
(3.). Consequtive
are very
evaporation decreases
losses
informative. molecular
products
through
of CO lead
(and probably
much
faster
smaller
than
present
They
ions.
that
(' 148) may be due to the
numbers
formed
the then
121 and 120.
314 as the protonated
and
the easier
at lower
176 and 177
to the C=N bond
and isobutane
since
-
ions m/z
adjacent
NH3
282
' C10H120 m/z 148
ions m/z
[M+H]+
under
-C8H7N02
fragment
rupture
Also
C17H16N03+ ID/Z
297
as contaminants
show
They
clearly
are also
contribution)
of m/z
314. Part
fragmentation
of of
of some
in the precipitate
study.
CONCLUSIONS In oxygen a formation with
containing of quinonoid
a subsequent
formation
water
structures
formation
of a black
solutions
the catechol
typical
of a ketimine
precipitate
which
end of dobutsmine
for o-dihydroxybenzene
function
which
is principally
together
a mixture
undergoes
derivatives lead
to the
of structures
2 and i.
REFERENCES 1. 2. 3. 4.
I. Buben and J. Pospisil, Tetrahedron Letters, (1967) 5123. S. Dayagi and Y. Degani, Ch. X in The Chemistry of the carbon-nitrogen double bond (ed. S. Patai). Wiley, New York, 1970. K.-P. Zeller, Ch. 5 in The Chemistry of the Quinonoid Compounds, Part (ed. S. Patai), Wiley, New York, 1974. W.J. Richter and W. Vetter, Org. Mass Spectrom. 2, (1969) 781.
1
International Journal of Mass Spectrometry and Zen Physics, 47 (1983) 483-486 Elsevier Scientific Publishing Company, Amsterdam - Printed in The Netherlands
EI/CI
MASS
SPECTRA
AND
THE
OXIDATION
PRODUCTS
OF DOBUTAMINE
UNDER
STORING
CONDITIONS
K. PIHLAJA
and A. M8TTBNEN
Laboratory
for Physical
Chemistry,
University
of Turku,
SF-20500
50,
Turku
Finland
ABSTRACT Dobutanine dissolved in different water and alcohol solutions produced a black precipitate at a rate dependent on the amount of dissolved oxygen. The C precipitate ia shown to consist mainly of compounds :;: (m/z 313) both with a ketimine function in &?%:P&ZZ::: and with a different quinonoid structure at the catechol end.
INTRODUCTION When were
storing
found
on the
dobutsmine
to become
amount
(A) in different
red and the rate
of dissolved
water
of this
and alcohol
change
solutions
of colour
to be
they
dependent
oxygen.
1
HO
HO If the
solutions
observed five
times
further
the
In addition high
were
whereas faster
than
solution
to
carefully
an oxygenated
degassed water
an untreated
became
dark
(EI) resolution
mass
of the
and
a black
When
the red
began
a thorough were
formation colour
the reaction
material
studies
reaction
no colour
developed
analyses
spectrometric
oxidation
nitrogen
solution.
TR-, IJV- and elemental
characterization
with
solution
was
about
proceeded
to precipitate.
low
(CT/ET]
necessary
and of its major
and
for a conclusive
proaucts.
RESULTS 11.25
was
g of 1 in 450 cm3 of water
covered
by
red and within about
3 days.
filtration, repeated always
an aluminiun a day After
washed
5 times back
folio.
it became 7 days
with
with
the black
same
to 450 cm3 after
0020-73S~/S3/0000-0000/$03.00
browngray
distilled
the
was kept After
precipitate
water
original
the
and thick.
and ether solution
the filtrations. 0
at 336 K for 7 days.
2 hours
was
solution
The
decanter
changed
The precipitation separated
and dried. adjusting
Before
had
began
in
through
The
procedure
its total
placing
light
volume
at 336 K the
1983 Elsetier Scientific Publishing Company
was
solution way
was
ll.25
The
were
obtained
(3:l v/v
which
the
The
Akademi.
was
resolution
EI mass
of the
a Pasteur-pipet. in 37
precipitate
(1:l v/v),
CI
W-
elemental
accurate
methanol
days.
and
In this Similar
in methanol-
and low resolution
solid
DX-300
7035
GC/MS
composition
number
the
(Jeol
Ltd MM in some
IR-,
on a LKP-9000
Hence
spectrometry
programmed
(MM 7035)
the
precipitate.
and VG Analytical
by
obtained
(especially
in the
or NH3
through
black
water
analyzed
were
determination
to be difficult
temperature
10 minutes
g of the
in ethanol
first
latter
impurities
Bremen
0.55
for
+ 1 % KOH by weight).
precipitate
from
oxygenated
g of ;3 yielded
products -water
always
in Tokyo,
in Manchester)
cases),
B/E
linked
by burning
turned
was
because
of
some
by
high
MAT-212
direct
and
out
reexamined
Finnigan
using scan
spectra
in _&bo
of hydrogens) product
mass
instrument
inlet
isobutane
in (also
(DX-300)
spectra.
DISCUSSION Simple
model
structures
reactions
from
(2, ref.
1) suggest
an initial
formation
of quinonoid
1:
k 2b Dehydrogenation hydrogen
of a secondary
acceptor
R1CH2CH2NHCH(
(ref.
amine
can
also
be
effected
by
an
(organic)
2): = C(CH3]CH2CH2R2
CH3)CH2CH2Rz
NCH(CH3)CH2CH2R2
RI=
Ho
0 0
HO
or its
oxidation
product
$
=
OH
485
Probably
an immediate
quinonoid
precipitation
and ketimine
structures
after saves
the
the
consequtive
latter
from
formation further
of the
reactions.
. Already
the
oxidation related
to this
the
quinonoid
and
4).
The
high
inlet
the
EI mass
(2) but
it was
resolution
the
former
out
evaporates
was,
that
that
m/z
313
pattern
however,
already
using
temperature
297 and m/z
compositions
of C ,gH1gNC3W
nuch
B/E
faster.
m/z
is a molecular
to see how m/z
fragmentation
especially
clearly
elemental
showed
difficult
the
functions
experiments
pointed
with
spectra
rather
ion. From
molecular
and ketimine
system
products which
low resolution
product
linked
297 can be
the
existence
evident
(refs.
programmed
313 are two
showed
3
direct
separate
and C18H19N04(A)
scans
of
from
that.
3
-CHhCH=NXIH-CH2i.
Or
0
m/z
192
from 148
4
and m/z
the M*',
m/z
from M+',
m/z
first
significant
165
w
or
-CH,-N
and
in a lesser
313 and m/z 297. These losses.
=c;CH i.
177 and ions were
The both
2-
extent again
m/z
>
C18H19N04 m/z 313
products
-C10H120
m/z
come 282
EI scan
from m/z
and m/z as the
313 are
+
f
I
148
C17H16N04 m/z 298
C10H10N03 m/z 192
-
extent
on the normal
primary
-CH3-
+-
and m/z
in a lesser
apparent
major
298
(2.1
> C8H7N03+ m/z
11-j
165
-C8H7N03'
+ +C10H120 m/z 148
(2.1
due
486
to
rupture
a bond
accompanied shows from m/z
adjacent
by a simultaneous
for instance the
ions m/z
107
to the
ions m/z
hydrogen m/z
164,
192 and m/z
is characteristic
C=N bond
transfer
137,
in the (ref.
136
m/z
through
165
which
of m/z
4). Further
and m/z
consequtive
for the phenolic
case
fragmentation
which
109
of CO
losses
end of the molecules
is
165
are formed (ref.
3).
(2 and 2).
-CH3' +' C18H19N03 m/z
+
I The primary bond
to ions m/z
the
indicative
m/z
298
the
ions
149,
for
ketimine
+
( C9HloNO)
148
298
its amount mass
decomposition
and m/z
CI-spectra
from h are again
(3.). Consequtive
are very
evaporation decreases
losses
informative. molecular
products
through
of CO lead
(and probably
much
faster
smaller
than
present
They
ions.
that
(' 148) may be due to the
numbers
formed
the then
121 and 120.
314 as the protonated
and
the easier
at lower
176 and 177
to the C=N bond
and isobutane
since
-
ions m/z
adjacent
NH3
282
' C10H120 m/z 148
ions m/z
[M+H]+
under
-C8H7N02
fragment
rupture
Also
C17H16N03+ ID/Z
297
as contaminants
show
They
clearly
are also
contribution)
of m/z
314. Part
fragmentation
of of
of some
in the precipitate
study.
CONCLUSIONS In oxygen a formation with
containing of quinonoid
a subsequent
formation
water
structures
formation
of a black
solutions
the catechol
typical
of a ketimine
precipitate
which
end of dobutsmine
for o-dihydroxybenzene
function
which
is principally
together
a mixture
undergoes
derivatives lead
to the
of structures
2 and i.
REFERENCES 1. 2. 3. 4.
I. Buben and J. Pospisil, Tetrahedron Letters, (1967) 5123. S. Dayagi and Y. Degani, Ch. X in The Chemistry of the carbon-nitrogen double bond (ed. S. Patai). Wiley, New York, 1970. K.-P. Zeller, Ch. 5 in The Chemistry of the Quinonoid Compounds, Part (ed. S. Patai), Wiley, New York, 1974. W.J. Richter and W. Vetter, Org. Mass Spectrom. 2, (1969) 781.
1