Reactions of phosphonioalkyl derivatives of phenylhydrazine and hydroxylamine

Article abstract of DOI:10.1007/s11176-005-0369-9

Triphenyl- and tributyl[2-(2-phenylhydrazino)ethyl]phosphonium salts undergo dehydrogenation on heating to form the corresponding phenylhydrazones in high yields. The phenylhydrazone formed from the triphenylphosphonium salt can also be prepared from trip

Full text of DOI:10.1007/s11176-005-0369-9

Russian Journal of General Chemistry, Vol. 75, No. 7, 2005, pp. 1069 1073. Translated from Zhurnal Obshchei Khimii, Vol. 75, No. 7, 2005,
pp. 1132 1136.
Original Russian Text Copyright
2005 by Ovakimyan, Barsegyan, Kikoyan, Indzhikyan.
Reactions of Phosphonioalkyl Derivatives
of Phenylhydrazine and Hydroxylamine
M. Zh. Ovakimyan, S. K. Barsegyan, N. M. Kikoyan, and M. G. Indzhikyan
Institute of Organic Chemistry, National Academy of Sciences of Armenia, Erevan, Armenia
Received March 11, 2004
Abstract Triphenyl- and tributyl[2-(2-phenylhydrazino)ethyl]phosphonium salts undergo dehydrogenation
on heating to form the corresponding phenylhydrazones in high yields. The phenylhydrazone formed from the
triphenylphosphonium salt can also be prepared from triphenyl(1-alkoxy-2-bromoethyl)phosphonium bromides.
The latter reaction is proposed to involve reduction of the COC group with phenylhydrazine. N,N-Diphospho-
nioethylation and N,N-diphosphoniopropylation of hydroxylamine are performed. Alkaline hydrolysis of the
resulting diphosphonium salts gave N,N-bis[2-(diphenylphosphoryl)ethyl(propyl)]hydroxylamines in high
yields.
Previously we found that triphenyl[2-(2-phenyl-
hydrazino]ethyl]phosphonium bromide (I) reacts with
aqueous sodium hydroxide to form cis- and trans-
(diphenylphosphoryl)acetaldehyde phenylhydrazone
[1].
1-alkoxyvinylphosphonium salts. Salt II is probably
formed by a scheme involving reduction of the C O C
bond with phenylhydrazine either directly in salts IV
or V or after replacement of bromine with the phenyl=
hydrazono group.
PhNHNH2
Further studies showed that the phenylhydrazone
is also formed from salt I in the absence of alkali.
Thus, refluxing of salt I in ethanol or DMF at 100 C
for some hours gave a mixture of cis- and trans-tri-
phenyl[2-(phenylhydrazono)ethyl]phosphonium bro-
mides in high yield.
Ph3P+ CH CH2Br
Ph3P+ CH CH2NHNHPh
Br
Br
OR
OR
IV, V
PhNHNH2
PhNHNH2
Ph3P+CH2CH2NHNHPh
Ph3P+CH2CH=NNHPh.
PhNHNH2
Ph3P+CH2CH2Br
Br
[Ph3P+CH2CH2NHNHPh]
Br
Br
Br
I
II
Phosphoniophenylhydrazone II is also formed by
alkylation of salt I with propargyl bromide and of the
tributylphosphonium analog of salt I (compound III)
with acrylonitrile in methanol under reflux. Note that
the reaction of (4-bromo-3-chlorobut-2-enyl)triphenyl-
phosphonium bromide with phenylhydrazine was
performed in a similar way [2]. This reaction is likely
to involve deprotonation of the hydrazine nitrogen
atom followed by expulsion of the neighboring
hydrogen atom that is almost as mobile as hydride
hydrogen. Deprotonation, in its turn, is favored by the
presence both of halide anions and of the lone electron
pair of hydrazine nitrogen.
Ph3P+ CH2CH=N NHPh
Br
R = C2H5 (IV), C4H9 (V).
Previously we showed [1] that the reaction of
ethylenebis(triphenylphosphonium) dibromide with
equimolar amount of hydroxylamine in the presence
of triethylamine affords [2-(hydroxylamino)ethyl)tri-
phenylphosphonium bromide.
X-ray diffraction analysis established that com-
pound VI is formed by dialkylation of hydroxylamine
and has the following structure.
It is interesting to note that the reactions with
phenylhydrazine with triphenylphosphonium salts
with a 1-ethoxy- or 1-butoxy-2-bromoethyl group
both gave, instead of expected nucleophilic substitu-
tion products, phosphoniophenylhydrazone II iden-
tical to that obtained from salt I, as well as much
Ph3P+ CH2CH2
Br
N OH
Ph3P+ CH2CH2
Br
VI
1070-3632/05/7507-1069 2005 Pleiades Publishing, Inc.

1070
OVAKIMYAN et al.
Attempted monoalkylation of the starting reagents
failed. N,N-Dialkylation products were also prepared
from (2-bromoethyl)tributylphosphonium and (3-bro-
mopropyl)triphenylphosphonium bromides (VIII).
OH
Bu3P+ CH2CH2Br
Bu3P+ CH2CH2 N CH2CH2 P+Br3
NH2OH
Br
Br
Br
VII
Ph3P+ CH2CH2CH2Br
Bu3P+ CH2CH2CH2 N CH2CH2CH2 P+Ph3
Br
Br
Br
VIII
OH
IX
Hydrolysis of salt VI with aqueous alkali gave
N,N-bis[2-(diphenylphosphoryl)ethyl]hydroxylamine
along with small amounts of cis- and trans-(diphenyl-
phosphoryl)hydroxylamines. On attempted recrystalli-
zation the latter converted into (diphenylphosphoryl)-
ethene according to the following scheme.
O
Ph3P+ CH2CH2
Ph3P CH2CH2
N OH
Ph3P CH2CH2
OH
Br
N OH
2C6H6
Ph3P+ CH2CH2
Br
VI
VIa
O
OH
Ph3P+ CH2 CH2
Br
Ph3P+ CH2 CH2
Ph3P + CH2=CH2 + [Ph3P+ CH2CH2N=O]
Br
N O
OH
C6H6
Ph2P CH=CH NHOH
O
[Ph2P+ CH=CH NHOH]
Br
[Ph2P+ CH2CH=N Oh]
Br
Ph2P CH=CH2
O
Dioxide VIa is readily alkylated with methyl
bromide to form an N-methoxy derivative, whereas
salt VI does not react under the same conditions. This
fact is probably explained by electronic effects of the
phosphonium groups, that operate to much reduce the
nucleophilicity of the nitrogen atoms. The reaction
probably occurs by the following scheme.
Ph2P(O)CH2CH2
Ph2P(O)CH2CH2
Ph2P(O)CH2CH2
Ph2P(O)CH2CH2
Ph2P(O)CH2CH2
Ph2P(O)CH2CH2
+
+
N OH + CH3Br
N OH
N OCH3
HBr
..
^
CH3
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REACTIONS OF PHOSPHONIOALKYL DERIVATIVES
1071
Hydrolysis of salt IX with aqueous alkali resulted
in exclusive formation of dioxide IXa.
5.6 g of a solid material whose recrystallization (ethyl
acetate ethanol) gave 2.9 g (50%) of salt III, mp
1
95 C. H NMR spectrum (CDCl3), , ppm (J, Hz):
Ph3P+CH2CH2CH2
0.91 t (9H, CH3CH2, JHH 7.1), 1.56 1.35 m [12H,
Br
N OH
CH3(CH2)2CH2], 2.37 2.25 m [6H, CH3(CH2)2CH2],
Ph3P+CH2CH2CH2
2
2.79 d.t (2H, PCH2, JHH 6.5, JPH 12.5), 3.34 d.t (2H,
Br
3
IX
CH2N, JHH 6.5, JPH 17.1), 6.73 t (H, p-C6H5,
JHH 7.3), 6.92 d (2H, o-C6H5, JHH 8.3), 7.13 d.d (2H,
m-C6H5, JHH 7.3, 8.5). 13C NMR spectrum (CDCl3),
C, ppm (J, Hz): 18.60 d (PCH2, J 42.2), 19.60 d
[PCH2(CH2)2CH3, J 47.1], 13.46 [PCH2(CH2)2CH3],
23.87 [PCH2(CH2)2CH3], 44.24 (NCH2), 149.06 (ipso-
NC6H5), 129.02, 113.61 (o- and m-NC6H5), 119.17
(p-NC6H5). Found Br , %: 18.98. C20H38BrN2P.
Calculated Br , %: 19.18.
Ph2P(O)CH2CH2CH2
OH
N OH
Ph2P(O)CH2CH2CH2
IXa
EXPERIMENTAL
The H, 31P, and 13C NMR spectra were obtained
on a Varian Mercuri-300 instrument (300 MHz) in
CDCl3 and DMSO. Thin-layer chromatography was
performed on Silufol UV-254 plates, developer iodine
vapor. The starting salts were prepared by known
procedures [1, 3].
1
Tributyl[2-(phenylhydrazono)ethyl]phospho-
nium bromide. Acrylonitrile, 0.16 g, was added to a
solution of 0.4 g of salt III in 10 ml of methanol, and
the mixture was refluxed for 16 h. The solvent was
then removed, and the residue was thoroughly washed
with dry ether and recrystallized from ethyl acetate
ethanol to obtain 0.35 g (84%) of tributyl[2-(phenyl-
hydrazono)ethyl]phosphonium bromide, mp 135 C, Rf
Triphenyl[2-(phenylhydrazono)ethyl]phospho-
nium bromide. a. Triphenyl[2-(2-phenylhydrazino]-
ethyl]phosphonium bromide (I), 0.5 g, was heated in
10 ml of DMF at 100 C for 9 h. The solvent was then
distilled off, and the residue was washed with dry
ether and dried in a vacuum to obtain 0.4 g (84%) of
compound II, mp 190 C. 1H NMR spectrum (DMSO),
, ppm (J, Hz): 4.90 d.d (2H, syn-PCH2, JPH 15.6,
JHH 5.0), 5.40 d.d (2H, anti-PCH2, JPH 17.0, JHH
5.7), 6.75 7.10 m (5H, NHC6H5), 7.60 8.00 m [16H,
P(C6H5)3, CH=N], 9.65 s and 10.20 s (1H, syn-, anti-
NH). Found Br , %: 16.21. C26H24BrN2P. Calculated
Br , %: 16.84.
1
0.79 (isobutanol acetic acid water, 5:2:2). H NMR
spectrum (DMSO), , ppm (J, Hz): 1.00 t (9H,
CH3CH2, JHH 7.1), 1.35 1.56 m (12H, CH3CH2CH2
CH2), 2.25 2.37 m [6H, CH3(CH2)2CH2], 3.60 d.d
(2H, syn-PCH2, 2JPH 16.5, JHH 5.0), 4.10 d.d (2H, anti-
2
2
2
PCH2, JPH 19.0, JHH 5.7), 6.70 t (1H, p-C6H5, JHH
7.3), 6.90 d (2H, o-C6H5, JHH 8.3), 7.10 d.d (2H,
m-C6H5, 1JHH 7.3, 2JHH 8.3), 7.30 m [1H, syn- and
anti-CH=N], 10.20 s [1H, NNH].
Reaction of (2-bromo-1-ethoxyethyl)triphenyl-
phosphonium bromide with phenylhydrazine. Phen-
ylhydrazine, 0.8 g, was added to a solution of 1.8 g
of salt IV in 20 ml of acetonitrile, and the mixture
was left to stand at room temperature for 24 h. The
solvent was then removed, and the residue was
washed with dry ether and diluted with methylene
chloride. Undissolved residue was filtered off and
dried to obtain 0.65 g (94%) of phenylhydrazine
hydrobromide (sublimed on melting above 195 C).
The methylene chloride solution was evaporated to
obtain 1.6 g of a mixture of phenylhydrazone II and
(1-ethoxyvinyl)triphenylphosphonium bromide (1:4,
b. Propargyl bromide, 0.12 g, was added to a solu-
tion of 0.5 g of salt I in ethanol, and the mixture was
refluxed for 5 h, after which the solvent was removed,
and the residue was washed with dry ether to obtain
0.5 g of a substance whose recrystallization (isopropyl
alcohol benzene) gave 0.25 g (25%) of compound II.
The melting point and 1H NMR spectrum of the
sample were consistent with those of the sample ob-
tained by procedure a.
Tributyl[2-(2-phenylhydrazino)ethyl]phospho-
nium bromide (III). Phenylhydrazine, 3 g, was added
to a solution of 5.5 g (2-bromoethyl)tributylphospho-
nium bromide in 25 ml of ethanol, and the reaction
mixture was left to stand for 2 days. The solvent was
then removed, and the residue was diluted with
methylene chloride. Undissolved material was filtered
off to obtain 2.6 g (98%) of phenylhydrazine hydro-
bromide (sublimed on melting above 195 C). The
methylene chloride solution was evaporated, and the
residue was washed with dry ether and dried to obtain
1
1H NMR data). H NMR spectrum of (1-ethoxyvinyl)
triphenylphosphonium bromide (CDCl3), , ppm (J,
Hz): 1.40 t (3H, OCH2CH2, JHH 6.5), 4.30 q (2H,
2
OCH2CH3, JHH 6.5), 5.10 d.d [1H, PC(O)CHH, JPH
3
129.0, JHH 5.8], 6.00 d.d [1H, PC(O)CHH, JPH 41.0,
JHH 5.8], 7.60 7.80 m (15H, C6H5P). 31P NMR spec-
trum (CDCl3), P, ppm: 20.
Reaction of (2-bromo-1-butoxyethyl)triphenyl-
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1072
OVAKIMYAN et al.
phosphonium bromide with phenylhydrazine. Phe-
nylhydrazine, 0.7 g, was added to a solution of 1.8 g
of salt V in 20 ml of acetonitrile, and the mixture was
left to stand at room temperature for 24 h and then
treated as described above to obtain 1.5 g of a mixture
of (1-butoxyvinyl)triphenylphosphonium bromide and
2.50 d.t (4H, PCH2, 2JPH 12.9, JHH 7.9), 2.90 d.t (4H,
NCH2, JPH 10.0, JHH 7.9), 7.40 7.80 m [20H,
3
P(C6H5)2]. Repeated recrystallization of the third com-
ponent from ethanol gave diphenyl(vinyl)phosphine
1
oxide. H NMR spectrum (CDCl3), , ppm (J, Hz):
6.20 6.40 m (2H, PCHCH2), 6.60 6.80 m (1H,
PCHCH2), 7.40 7.80 m (10H, PC6H5). 31P NMR spec-
trum (CDCl3), P, ppm: 24.50. Compound VIa was
reacted with methyl bromide to obtain N,N-bis[2-(di-
phenylphosphory)lethyl]-O-methylhydroxylamine
1
1
phenylhydrazone II (3:1, H NMR data). H NMR
spectrum of (1-butoxyvinyl)triphenylphosphonium
bromide (CDCl3), , ppm (J, Hz): 0.90 t [3H,
O(CH2)3CH3, JHH 6.5], 1.10 1.30 m [2H, O(CH2)2
CH2CH3], 1.60 1.80 m (2H, OCH2CH2CH2CH3),
4.10 t [2H, OCH2(CH2)2CH3, JHH 6.5], 5.10 d.d [1H,
1
bromohydrate. H NMR spectrum (DMSO), , ppm (J,
2
3
Hz): 3.10 d.t (4H, PCH2, JPH 12.9, JHH 7.9), 3.50 s
3
3
3
PC(O)CHH, JPH 12.5, JHH 6.0], 5.90 d.d [1H,
(3H, NOCH3), 4.00 d.t (4H, NCH2, JPH 11.2, JHH
7.9), 7.40 7.85 m [20H, (C6H5)2P], 12.30 br.s (1H,
NH). 31P NMR spectrum (DMSO), P, ppm: 34.13.
Found Br , %: 13.10. C29H32BrNO3P2. Calculated Br ,
%: 13.69.
3
PC(O)CHH, JPH 39.5, JHH 6.0], 7.60 7.90 m [15H,
(C6H5)3P].
N,N-Bis[2-(tributylphosphonio)ethyl]hydroxyl-
amine dibromide. Triethylamine, 1.4 g, was added
dropwise to a mixture of 5.4 g of (2-bromoethyl)tri-
butylphosphonium bromide in 40 ml of methylene
chloride and 0.5 g hydroxylamine hydrochloride. The
mixture was left to stand for 3 days at room tempera-
ture and then diluted with water. The organic layer
was separated and dried over magnesium sulfate. The
solvent was removed, and the residue was dried and
recrystallized (ethyl acetate ethanol) to obtain 3.5 g
Reaction of (3-bromopropyl)triphenylphos-
phonium bromide with hydroxylamine. Triethyl-
amine, 0.9 g, was added dropwise to a solution of 2 g
of salt VIII prepared as described in [3] [1H NMR
spectrum (DMSO), , ppm (J, Hz): 2.10 m (2H,
CH2CH2CH2), 3.70 t (2H, CH2Br), 3.95 d.t (2H,
2
3
P+CH2, JPH 13.9, JHH 6.8)] and 0.3 g of hydroxyl-
amine hydrochloride in 10 ml of chloroform, and the
reaction mixture was refluxed for 19 h. After cooling,
the solution was diluted with water, the organic layer
was separated, dried over magnesium sulfate, the
solvent was removed, and the residue was dried to
obtain 1.5 g (78%) of N,N-bis[3(triphenylphosphonio)-
propyl]hydroxylamine dibromide (IX), mp 253
1
(77%) of salt VII, mp 150 C. H NMR spectrum
(DMSO), , ppm (J, Hz): 1.00 m {18H, P[(CH2)3
CH3]3}, 1.50 m {24H, P[CH2(CH2)2CH3]3}, 2.40 m
{12H, P[CH2(CH2)2CH3]3}, 2.65 d.t (4H, PCH2, 2JPH
3
3
3
13.3, JHH 6.9), 3.33 d.t (4H, NCH2, JPH 15.3, JHH
6.9). 31P NMR spectrum (DMSO), , ppm: 38.84.
Found Br , %: 24.30. C28H63Br2NOP2.PCalculated Br ,
%: 24.58.
1
255 C. H NMR spectrum (DMSO), , ppm (J, Hz):
1.80 m [4H, (CH2CH2CH2)2 ], 2.90 t (4H, CH2N),
2
3
Alkaline hydrolysis of N,N-bis[2-(triphenyl-
phosphonio)ethyl]hydroxylamine dibromide. To
3 g of salt VI {1H NMR spectrum (CDCl3), , ppm
4.10 d.t [4H, (PCH2)2, JPH 12.0, JHH 6.8], 7.62
8.10 m {30H, [P(C6H5)3]2}. 31P NMR spectrum
(DMSO), P, ppm: 30.73. Found Br , %: 19.95.
C42H43Br2NOP2. Calculated Br , %: 20.02.
3
3
(J, Hz ): 3.33 d.t (4H, NCH2, JPH 11.4, JHH 6.90),
3.78 d.t [4H, (P+CH2)2, JPH 13.2, JHH 6.9], 7.62
7.86 m [30H, P(C6H5)3], 8.75 s (1H, NOH)} in 15 ml
of benzene, 1.2 ml of 25% aqueous solution of 0.6 g
of sodium hydroxide, and the reaction mixture was
refluxed for 12 h. The organic layer was separated,
and the aqueous solution was treated with benzene.
The combined benzene extracts were dried over
magnesium sulfate and evaporated to leave 1.3 g of a
mixture of triphenylphosphine oxide, N,N-bis[2-(di-
phenylphosphory)lethyl]hydroxylamine, and diphenyl-
[2-(hydroxylamino)vinyl]phosphine oxide (1H NMR
data). Fractional crystallization of the mixture allowed
the first two components to be separated pure and
2
3
Alkaline hydrolysis of N,N-bis[3-(triphenyl-
phosphonio)propyl]hydroxylamine dibromide. To a
solution of 2 g of salt IX in 10 ml of benzene, 0.8 ml
of a 25% aqueous solution of 0.4 g of sodium hydr-
oxide, and the reaction mixture was refluxed for 3 h.
Benzene was removed from the reaction mixture by
steam distillation, and the residue was washed with
water and dried to obtain 1.2 g (92%) of N,N-bis[3-(tri-
phenylphosphoryl)propyl]hydroxylamine, mp 209
1
210 C. H NMR spectrum (CDCl3), , ppm (J, Hz):
2.02 m [4H, (CH2CH2CH2)2], 2.50 d.t [4H, (PCH2)2,
3
2JPH 11.3, JHH 7.0], 2.98 t [4H, (CH2)2N], 7.40
7.80 m [20H, (PC6H5)2]. 13C NMR spectrum (CDCl3),
C, ppm (J, Hz): 18.60 d (CH2, JPC 3.5), 26.84 d
(PCH2, 1JPC 71.9), 59.94 d (NCH2, 2JPC 9.6), 128.87 d
(m-C6H5P, JPC 11.7), 130.98 d (o-C6H5P, JPC 9.4),
identified by the H and 31P NMR spectra. 31P NMR
1
spectrum of triphenylphosphine oxide, P, ppm: 29.6.
1H NMR spectrum of N,N-bis[2-(diphenylphosphoryl)-
ethyl]hydroxylamine (CDCl3),
, ppm (J, Hz):
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REACTIONS OF PHOSPHONIOALKYL DERIVATIVES
1073
131.98 d (p-C6H5P, JPC 2.6), 132.76 d (ipso-C6H5P,
JPC 99.80).
Nauk, Ser. Khim., 2002, no. 9, p. 1601.
2. Ovakimyan, M.Zh., Barsegyan, S.K., Pogosyan, A.S.,
Kikoyan, N.M., Panosyan, G.A., and Indzhikyan, M.G.,
Zh. Obshch. Khim., 2004, vol. 74, no. 12, p. 1992.
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1. Ovakimyan, M.Zh., Barsegyan, S.K., Karapetyan, A.A.,
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RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 75 No. 7 2005