1,2-Dihydropyrazolo- and 1,2-dihydrothieno-1λ5-[2,4,1]-diazaphosphinines [6]

Full text of DOI:10.1023/A:1013212723860

Chemistry of Heterocyclic Compounds, Vol. 37, No. 9, 2001
1,2-DIHYDROPYRAZOLO- AND
1,2-DIHYDROTHIENO-1λ5
-
[2,4,1]-DIAZAPHOSPHININES
S. A. Kovaleva, N. G. Chubaruk, A. A. Tolmachev, and A. M. Pinchuk
Keywords: 1,2-dihydropyrazolodiazaphosphinine, 1,2-dihydrothienodiazaphosphinine, pyrazole,
thiophene.
In previous work [1], we showed that the reaction of N1,N1-dimethyl-N2-5-pyrazolyl- and
N1,N1-dimethyl-N2-5-thienylforamidines with trivalent phosphorus halides permits the introduction of a
dihalophosphine group into the hetaryl residue at the position adjacent to the amidine function and opens broad
possibilities for the modification of heterocycles by introducing various substituents at the phosphorus atom and
by means of intramolecular heterocyclization [1, 2].
We have found that 3-methyl-5-(α-methylaminobenzylidene)amino-1-phenylpyrazole
(
1) and
-(α
5
-methylaminobenzylidene)amino-2-methoxycarbonylthiophene (2), which contain an NH function in the
amidine fragment, react with phosphorus tribromide at two nucleophilic sites, namely, the nitrogen atom of the
NH group and a heteroaromatic carbon atom to give 1-bromo-1,2-dihydro-1λ3
-[2,4,1]-diazaphosphinines 3 and
4, which were characterized by 31P NMR spectroscopy. Products 3 and 4 were used to synthesize
1
13
tetracoordinated phosphorus derivatives 5 and 6, whose structures were confirmed using 31P, H, and C NMR
spectroscopy.
O
Br
Me
Me
P
Me
N
O
N
PBr3
Ph
N
Me
Ph
P
N
Me
N
C
Ph
N
Ph
N
N
HN
N
Ph
N
N
Me
3
1
N
Ph
5
O
1.
HN
O
O
S
Br
Me
N
N
Me
Ph
P
PBr3
P
Ph
N
2. H2O2
N
C
S
COOMe
Ph
HN
Me
N
N
2
S
COOMe
COOMe
4
6
__________________________________________________________________________________________
Institute of Organic Chemistry, National Academy of Sciences of Ukraine, Kiev 252660, Ukraine,
e-mail: hetfos@ukrpack.net. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1287-1289,
September, 2001. Original article submitted May 5, 2001.
0009-3122/01/3709-1183$25.00©2001 Plenum Publishing Corporation
1183

The X-ray diffraction structural analysis data of 6 will be published in a subsequent communication.
The NMR spectra were taken on a Varian 300 spectrometer at 300 MHz for the 1H NMR spectra and at
31
75 MHz for the 13C NMR spectra with TMS as the intermal standard and at 121 MHz for the P NMR spectra
with 85% H3PO4 as the external standard. All the operations with the trivalent phosphorus derivatives were
carried out using dry solvents in an argon atmosphere.
2-Methoxycarbonyl-5-(α-methylaminobenzylidene)aminothiophene (2).
A sample of (N-methyl)-
benzimidoyl chloride (0.01 mol) was added with stirring to a solution of (0.01 mol) 5-amino-2-
methoxycarbonylthiophene (0.01 mol) and triethylamine (0.011 mol) in benzene (30 ml) cooled to 10°C. The
reaction mixture was maintained for 12 h at 25°C. The precipitate was filtered off and the mother liquor was
evaporated. The solid oily residue was recrystallized to give 2 in 47% yield; mp 133-134°C (ethanol). 1H NMR
), δ, ppm,
spectrum (DMSO-d6
J (Hz): 3.65 (3H, s, CH3–O); 2.88 (3H, d, JHH = 4.5, CH3–N); 6.61 (1H, d,
J
HH = 3.9, CH=C–N, hetaryl); 7.29-7.48 (6H, m, C6H5 + CH=C–C, hetaryl); 7.88 (1H, br. s, NH). Found, %:
C 61.25, 61.27; H 5.11, 5.14; N 10.19, 10.22. C14H14N2O2S. Calculated, %: C 61.29; H 5.14; N 10.21.
3-Methyl-5-(α-methylaminobenzylidene)amino-1-phenylpyrazole (1)
was synthesized in 80% yield
1
analogously to 2 from 5-amino-3-methyl-1-phenylpyrazole; mp 203-204°C (ethanol–water). H NMR spectrum
), δ, ppm,
(CDCl3
J (Hz): 2.09 (3H, s, CH3–C); 3.03 (3H, br. s, CH3–N); 4.89 (1H, s, hetaryl); 4.82 (1H, br. s,
NH); 7.72 (2H, d, 3JHH = 7.8, o-C6H5–N); 7.13-7.39 (8H, m, m,p-C6H5N + C–C6H5). Found, %: C 74.44, 74.48;
H 6.24, 6.27; N 19.35, 19.31. C18H18N4. Calculated, %: C 74.46; H 6.25, N 19.29.
λ5
e
6-Methoxycarbonyl-2-methyl-1-morpholino-1-oxo-3-phenyl-1,2-dihydro-1 -thieno[3,2- ]-2,4,1-
diazaphosphinine (6). A sample of phosphorus tribromide (0.01 mol) was added with stirring to a solution of
31
compound 2 (0.01 mol) in pyridine (10 ml) cooled to 10°C and maintained at 25°C for 3 h. P NMR spectrum
of 1-bromo-1,2-dihydro-1λ3
δP: 107 ppm. The mixture was cooled to
-thieno[3,2-e]-2,4,1-diazaphosphinine 4
10°C and morpholine (0.04 mol) was added with stirring. After 2 h, pyridine was evaporated in vacuum. The
residue was dissolved in benzene (20 ml) and 30% aq. hydrogen peroxide (5 ml) was added with stirring and
cooling. The reaction mixture was stirred for 5 h. Then, the organic layer was separated, washed with two 30-ml
water portions, and evaporated in vacuum. The oily residue was crystallized; mp 193-194°C (2-propanol). Yield
31
1
), δP: 9 ppm.
), δ, ppm,
H NMR spectrum (CDCl3
of 6 40%. P NMR spectrum (CHCl3
J (Hz): 3.92 (3H, s,
CH3–O); 3.15 (3H, d, 3JHP = 6.6, CH3–N); 2.99 and 3.26 (4H, m, CH2–N); 3.64 (4H, m, CH2–O); 7.43-7.52 (5H,
m, CAr); 7.94 (1H, d, JHP = 5.7, hetaryl). C NMR spectrum (CDCl3
3
13
2
), δ, ppm,
J (Hz): 32.79 (d, JCP = 5.7,
3
1
CH3N), 44.70 (s, –CH2N), 52.77 (s, CH3OC(O)), 67.54 (d, JCP = 5.3, CH2O), 111.15 (d, JCP = 169, C–P),
127.97 (s, m-CAr), 129.18 (s, o-CAr), 129.53 (d, 3JCP = 19.7, C(6)), 130.51 (s, p-CAr), 131.27 (d, 2JCP = 13.7, C(7)),
135.59 (d, 3JCP = 5.7, i-CAr), 160.54 (s, C(3)), 162.45 (s, C=O), 167.51 (d, 3JCP = 10.9, S–C–N). Found, %: P 7.59,
7.61; N 10.40; 10.37. C18H20N3O4PS. Calculated, %: P 7.64; N 10.36.
1λ5
e
2,7-Dimethyl-1-(morpholino)-1-oxo-3,5-diphenyl-5H- -pyrazolo[4,5- ]-2,4,1-diazaphosphinine (5)
31
was synthesized in 60% yield analogously to 6 from pyrazole 1. P NMR spectrum of intermediate 1-bromo-
2,7-dimethyl-3,5-diphenyl-1,2-dihydro-5H-1λ3
), δP: 120 ppm. The
-pyrazolo[4,5-e]-2,4,1-diazaphosphinine (3
31
1H NMR spectrum (CDCl3),
), δP: 11.6 ppm.
mp of 5 210-211°C (2-propanol). P NMR spectrum (CHCl3
3
δ,
ppm, J (Hz): 2.58 (3H, s, CH3–C); 3.14 (3H, d, JHP = 6.6, CH3–N); 3.05 and 3.30 (4H, m, CH2–N); 3.68 (4H,
t, 3JHH = 4.5, CH2–O); 7.94 (2H, d, 3JHH = 7.5, o-CPh-N); 7.22-7.55 (8H, m, m,p-CPh-N + CPh-C). Found, %: P 7.40,
7.38; N 16.65, 16.68. C22H24N5O2P. Calculated, %: P 7.35; N 16.62.
REFERENCES
1.
2.
G. V. Oshovsky, A. M. Pinchuk, and A. A. Tolmachev, Mendeleev Commun., 9, 161 (1999).
S. A. Kovaleva, S. P. Ivonin, A. M. Pinchuk, and A. A. Tolmachev, Khim. Geterotsikl. Soedin., 1285
(2001).
1184