Chemistry of Heterocyclic Compounds, Vol. 37, No. 8, 2001
2-DIALKOXYPHOSPHORYL-
1,4-DIHYDROBENZODIAZINES
F. I. Guseinov, Kh. A. Asadov, R. N. Burangulova, and V. V. Moskva
Keywords: benzimidazole, o-phenylenediamine, 2-phosphoryl-1,4-dihydrobenzodiazines, chloro-
phosphorylacetaldehydes.
α-halocarbonyl compounds with
The condensation of
o-phenylenediamine proceeds to give linear
enamines [1], benzodiazines [2], and benzimidazole (cleavage of a carbon–carbon bond) [3]. Hence, it was of
interest to study the reactions of chlorophosphorylacetaldehydes 1 with o-phenylenediamine.
The reaction of chloro aldehydes 1a-1c with o-phenylenediamine proceeds through two pathways.
1) Chloro aldehydes 1a and 1b undergo heterocyclization to give phosphorylated benzodiazines 2. 2) In the case
of chloro aldehyde 1c, a C–C bond is broken to give benzimidazole and chlorobenzylphosphonate.
H
N
H
X = H
.
HCl
O
(RO)2P
X
N
H
P(OR)2
O
H2N
H2N
+
Cl
2a,b
CHO
O
N
1
X = Ph
Ph
(EtO)2P
H
+
N
H
Cl
a R = Et, X = H; b R = i-Pr, X = H; c R = Et, X = Ph
2-Diethoxyphosphoryl-1,4-dihydrobenzodiazine Hydrochloride (2a). A solution of aldehyde 1a
(0.86 g, 4 mmol) in ether (5 ml) was added with stirring to a solution of o-phenylenediamine (0.43 g, 4 mmol) in
ether (20 ml) at 0°C. The reaction mixture was stirred with cooling for 1 h and at room temperature for 2 h. The
precipitate of 2a was filtered off and recrystallized from ethanol–acetonitrile to give 1.03 g (84%) 2a,
31P NMR spectrum, δ, ppm: 13.0.
mp 112-113°C. IR spectrum, , cm-1: 1280, 1635, 3200.
1H NMR spectrum
ν
), δ, ppm,
(DMSO-d6
J (Hz): 1.10 (6H, t, 2CH3); 4.00 (4H, m, 2OCH2); 6.80 (2H, q, Ph); 7.15 (2H, q, Ph); 7.80
2
(1H, d, JPH = 7.5, CH); 13.25 (1H, s, NH); 14.10 (1H, s, NH). Found, %: Cl 11.85; N 9.17; P 10.31.
C12H18ClN2O3P. Calculated, %: Cl 11.66; N 9.19; P 10.18.
2-Diisopropoxyphosphoryl-1,4-dihydrobenzodiazine Hydrochloride (2b) was obtained analogously
in 87% yield; mp 121-122°C. IR spectrum, , cm-1: 1285, 1640, 3250. 31P NMR spectrum: 13.16. H NMR
1
ν
), δ, ppm,
spectrum (DMSO-d6
J (Hz): 1.15 (12H, t, 4CH3); 4.50 (2H, m, 2OCH); 6.90 (2H, q, Ph); 7.10 (2H, q,
3
Ph); 7.80 (1H, d, JPH = 7.5, CH); 13.30 (1H, s, NH); 14.20 (1H, s, NH). Found, %: Cl 10.76; N 8.54; P 9.45.
C14H22ClN2O3P. Calculated, %: Cl 10.68; N 8.42; P 9.32.
__________________________________________________________________________________________
Kazan State Technological University, 420015 Kazan, Russia, e-mail: eltos@Kai.ru. Translated from
Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1134-1135, August, 2001. Original article submitted
February 27, 2001.
1044
0009-3122/01/3708-1044$25.00©2001 Plenum Publishing Corporation