Novel benzodiazaphosphinines with an endocyclic P-C bond

Full text of DOI:10.1023/A:1011685411965

Chemistry of Heterocyclic Compounds, Vol. 37, No. 5, 2001
NOVEL BENZODIAZAPHOSPHININES
WITH AN ENDOCYCLIC P–C BOND
A. O. Pushechnikov, D. G. Krotko, D. M. Volochnyuk, and A. A. Tolmachev
Keywords: phosphorus(III) halides, diarylureas, heterocyclization.
Phosphorylation of substituted ureas is a synthetic method for phosphorus-containing heterocycles [1-4].
It was of interest to study the possibility of formation of condensed phosphorus-containing heterocyclic systems
by C-phosphorylation of electron-enriched diarylureas containing a ureide group in the position ortho to the
C-nucleophilic center of the benzene ring. By reaction of phosphorus(III) halides with ureas 1 and 2, we
synthesized novel types of condensed phosphorus-containing systems with a 2,4,1-benzodiazaphosphinine ring
(3-6); we did not isolate compound 5 when the P-thioxide 6 was obtained.
31
1
The structure of the synthesized compounds was confirmed by P and H NMR. A characteristic sign
1
that a ring was formed in the case of compound 3 is the presence in the H NMR spectrum of only one signal
from the NH proton, and also the absence of a signal from the proton in the 4 position of the phenylenediamine
moiety and a change in the character of the spin–spin coupling of the protons in it; and in the case of compound
6, the absence in the 1H NMR spectrum of a signal from the NH proton and simplification (as compared with the
starting urea 2) of the part of the spectrum assigned to the aromatic protons of the benzodioxane moiety. In the
latter case, the signals from protons at the C(5) and C(10) atoms appear as two doublets with spin–spin coupling
constant at the phosphorus atom of 6.3 Hz and 13.8 Hz, respectively.
NHAr
O
S
N
O
N
N
N
H
O
P
Ar
O
P
Ar
O
1
S
O
PBr2
N
N
H
N
N
H
C5H5N
2
3
Ar = 3,4-Cl2C6H3
Br
P
S
NEt2
Ph
O
O
O
Ph
O
P
O
NHPh
O
Et2NH
S
PBr3
3Et3N
N
N
O
N
N
O
N
O
4
6
5
δP = 103.4 ppm
__________________________________________________________________________________________
Institute of Organic Chemistry, National Academy of Sciences of Ukraine, Kiev 02094; e-mail:
azole@i.com.ua. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 710-712, May, 2001.
Original article submitted November 10, 2000.
0009-3122/01/3705-0659$25.00©2001 Plenum Publishing Corporation
659

Ureas 1 and 2 were synthesized by a general procedure from the corresponding anilines and isocyanates
in dioxane [5].
1
N-(3,4-Dichlorophenyl)-N'-[3-(dimethylamino)phenyl]urea (1). Mp 207-209°C. H NMR spectrum
(DMSO-d6), , ppm, J, Hz: 2.87 (6H, s, Me2N); 6.39 (1H, dd, 1J = 8.0, 2J = 2); 6.70 (1H, dd, 1J = 8.0, 2J = 1.2);
δ
6.91 (1H, t, 2J = 1.6); 7.07 (1H, t, 1J = 8.0); 7.32 (1H, dd, 1J = 8.8, 2J = 2.4); 7.5 (1H, d, 1J = 8.8): 7.88 (1H, d,
2J = 2.4); 8.62 (1H, s, NH); 8.90 (1H, s, NH). Found, %: C 55.67; H 4.54; N 12.96; Cl 21.37. C15H15Cl2N3O.
Calculated, %: C 55.57; H 4.66; N 12.96; Cl 21.87.
1
N-Ethyl-N-(3,4-ethylenedioxyphenyl)-N'-phenylurea (2). Mp 90-92°C. H NMR spectrum (CDCl3),
, ppm, J, Hz: 1.15 (3H, t, NCH2CH3); 3.72 (2H, q, NCH2); 4.30 (4H, s, OC2H4O); 6.18 (1H, br. s, NH); 6.76
δ
(1H, dd); 6.83 (1H, d); 6.96 (1H, m); 6.99 (1H, t); 7.25 (4H, m). Found, %: N 9.2; P 7.42. C20H18Cl2N3O2P.
Calculated, %: N 9.68; P 7.13.
2-(3,4-Dichlorophenyl)-6-dimethylamino-1-(5-methyl-2-furyl)-1,4-dihydro-2,4,1-benzodiaza-
phosphinan-3-one (3). A solution of diarylurea 1 (1.9 g, 5.88 mmol) in pyridine (10 ml) was added with stirring
to a solution of dibromo(5-methyl-2-furyl)phosphine (1.6 g, 5.88 mmol) in pyridine (10 ml). This was allowed
to stand at ~20°C for 2 days. Then triethylamine (1.8 g, 17.64 mmol) was added and it was stirred for 0.5 h.
Pyridine was evaporated under vacuum, and the product was extracted with hot toluene and reprecipitated with
hexane. Yield 1.8 g (70.5%); mp 210-215°C (MeCN, with decomposition). 31P NMR spectrum (CHCl3):
1
11.3 ppm. H NMR spectrum (CDCl3), , ppm, J, Hz: 2.28 (3H, s, Me); 2.87 (6H, s, Me2N); 5.90 (1H, s); 6.18
δ
2
1
1
(1H, s); 6.29 (1H, d, J = 2.7); 6.46 (1H, d, J = 8.1); 7.21 (1H, d); 7.26 (1H, dd); 7.42 (1H, d, J = 8.1); 7.48
(1H, s); 8.75 (1H, br. s, NH). Found, %: N 8.61; P 6.83; S 7.2. C20H18Cl2N3O2PS. Calculated, %: N 9.01; P 6.64;
S 7.2.
5
2-(3,4-Dichlorophenyl)-6-dimethylamino-1-(5-methyl-2-furyl)-3-oxo-1,4-dihydro-2,4,1 -benzo-
λ
diazaphosphinine-1-thioxide (4). Elemental sulfur (0.034 g, 1.1 mmol) was added to a solution of
benzodiazaphosphinane 3 (0.5 g, 1.1 mmol) in pyridine (10 ml). After the sulfur dissolved, the pyridine was
evaporated under vacuum, the residue was recrystallized from 2-propanol. Yield 0.2 g (39%); mp 266°C.
31P NMR spectrum (DMSO): 38 ppm. H NMR spectrum (DMSO-d6), , ppm, J, Hz: 2.32 (3H, s, Me); 2.98
1
δ
(6H, s, Me2N); 6.23 (1H, br.); 6.35 (1H, br. d, J = 4.4); 6.60 (1H, d, J = 9.3); 6.95 (2H, m); 7.18 (1H, br.); 7.31
1
1
(1H, d, J = 8.5); 7.65 (1H, d, J = 8.5); 10.60 (1H, s, NH). Found, %: C 68.4; H 6.05; N 9.75. C17H18N2O3.
Calculated, %: C 68.44; H 6.08; N 9.39.
5
1-Diethylamino-3-oxo-2-phenyl-4-ethyl-6,7-ethylenedioxy-1,4-dihydro-2,4,1 -benzodiazaphosphinine-
λ
1-thioxide (6). Phosphorus tribromide (0.15 ml, 1.59 mmol) and triethylamine (0.67 ml, 4.78 mmol) were added
with stirring to a solution of urea 2 (0.5 g, 1.59 mmol) in pyridine (50 ml). After 2 days, diethylamine (0.17 ml,
1.59 mmol) and elemental sulfur (0.051 g, 1.59 mmol) were added with stirring to the reaction mixture. After
the sulfur dissolved, the pyridine was evaporated off under vacuum, and the residue was triturated with water
and recrystallized from 2-propanol. Yield 0.35 g (51%); mp 170°C. 31P NMR spectrum (acetone): 60.4 ppm.
1H NMR spectrum (CDCl3), , ppm, J, Hz: 0.79 (6H, t, PNCH2CH3); 1.33 (3H, t, 4-NCH2CH3); 3.02 (2H, dt,
δ
PNCH2); 3.24 (2H, dt, PNCH2); 4.01 (2H, m, 4-NCH2); 4.28 (2H, t, OCH2); 4.32 (2H, t, OCH2); 6.67 (1H, d,
Jm-PCCH = 6.3, 5-CH); 7.24 (1H, Jo-PCCH = 13.8, d, 10-CH); 7.39 (5H, m, NPh). Found, %: N 9.63; P 7.11; S 7.5.
C21H26N3O3PS. Calculated, %: N 9.63; P 7.11; S 7.5.
REFERENCES
1.
2.
K. V. Nikonorov, E. A. Gurylev, A. A. Antokhina, and Z. Ya. Latypov, Izv. Akad. Nauk SSSR, Ser.
Khim., 2796 (1981).
L. Lamande and A. Munoz, Tetrahedron Lett., 32, 763 (1991).
660

3.
4.
5.
M. Farkens, T. G. Meyer, I. Neda, R. Sonnenburg, C. Mueller, A. K. Fischer, P. G. Jones, and
R. Schmutzler, Z. Naturforsch. B. Chem. Sci., 49, 145 (1994); Chem. Abstr. 121, 83452 (1994).
M. Yu. Dmitrichenko, V. G. Rozinov, V. I. Donskikh, G. V. Ratovskii, L. M. Sergienko,
G. V. Dolgushin, and R. B. Valeev, Zh. Obshch. Khim. 58, 2252 (1988).
Houben-Weyl, Methods of Organic Chemistry [in German], Georg Thieme Verlag, Stuttgart (1990),
Vol. 8, p. 157.
661