Transformation of trinitromethyl group into cyano: A new synthesis of 1,3,5-triazinecarbonitriles

Article abstract of DOI:10.1134/s1070428008030226

1,3,5-Triazine-2-carbonitriles were synthesized by reactions of 2-trinitromethyl-1,3,5-triazines with triphenylphosphine.

Full text of DOI:10.1134/s1070428008030226

ISSN 1070-4280, Russian Journal of Organic Chemistry, 2008, Vol. 44, No. 3, pp. 452–455. © Pleiades Publishing, Ltd., 2008.
Original Russian Text © V.V. Bakharev, A.A. Gidaspov, E.V. Peresedova, 2008, published in Zhurnal Organicheskoi Khimii, 2008, Vol. 44, No. 3,
pp. 454–456.
Transformation of Trinitromethyl Group into Cyano:
A New Synthesis of 1,3,5-Triazinecarbonitriles
V. V. Bakharev, A. A. Gidaspov, and E. V. Peresedova
Samara State Technical University, ul. Molodogvardeiskaya 244, Samara, 443100 Russia
e-mail: knil@sstu.smr.ru
Received March 26, 2007
Abstract—1,3,5-Triazine-2-carbonitriles were synthesized by reactions of 2-trinitromethyl-1,3,5-triazines with
triphenylphosphine.
DOI: 10.1134/S1070428008030226
Up to now, only two kinds of transformations of
the trinitromethyl group in trinitromethyl derivatives of
1,3,5-triazines have been reported: substitution by the
action of nucleophilic reagents [1–4] and denitration
to dinitromethyl-1,3,5-triazine salts [5–7]. We have
revealed a novel transformation of the trinitromethyl
group into cyano in the reaction of trinitromethyl-
1,3,5-triazines with triphenylphosphine. A few ex-
amples of reactions of mononitro compounds with
phosphines and phosphites are known. These are syn-
thesis of 1,3-benzodioxole-5-carbonitrile from 5-nitro-
methyl-1,3-benzodioxole and tributylphosphine in the
presence of azobis(isobutyronitrile) (AIBN) [8], reac-
tion of α-chloro(bromo)-α-nitrotoluene with triethyl
phosphite with formation of benzonitrile and phenylni-
trometane [9], formation of benzonitrile and 3,4-di-
phenyl-1,2,5-oxadiazole N-oxide in the reaction of
α-bromo-α-nitrotoluene with triphenylphosphine [10],
and preparation of octanenitrile from 1-bromo-1-nitro-
octane and triphenylphosphine [11]. Reactions of gem-
inal polynitro compounds with phosphines and phos-
phites were not reported.
corresponding 4,6-substituted 1,3,5-triazine-6-carboni-
triles XI–XX and triphenylphosphine oxide (Scheme 1).
Here, it was necessary to use four equivalents of tri-
phenylphosphine to achieve complete conversion of
the initial trinitromethyl derivative.
In the IR spectra of triazinecarbonitriles XI–XX
we observed a very weak absorption band at 2255–
2248 cm–1 due to stretching vibrations of the cyano
group. The low intensity of this band results from
1
conjugation with the 1,3,5-triazine ring. The H NMR
spectra of these compounds contained signals from
protons in the substituents on C4 and C6.
We believe that the transformation of trinitrometh-
yl-1,3,5-triazines I–X into 1,3,5-triazinecarbonitriles
XI–XX includes three consecutive reactions. The proc-
ess begins with biphilic [12] attack by triphenylphos-
phine on the oxygen atom of one nitro group in the
trinitromethyl moiety of I–X (Scheme 2). Partial con-
jugation between the lone electron pair on the phos-
phorus atom in triphenylphosphine and π-electron sys-
tems of the aromatic rings reduces its nucleophilicity.
As a result, electron transfer from the oxygen atom to
d orbitals of the phosphorus atom becomes predomi-
4,6-Substituted 2-trinitromethyl-1,3,5-triazines I–X
reacted with triphenylphosphine in toluene to give the
Scheme 1.
R'
N
R'
Toluene
N
N
+ 4Ph3P
N
N
+ 4Ph3P=O
R
C(NO2)3
R
N
CN
I–X
XI–XX
I, XI, R = R′ = MeO; II, XII, R = R′ = i-PrO; III, XIII, R = R′ = 3-MeOCOC6H4O; IV, XIV, R = MeO, R′ = pyrrolidin-1-yl; V, XV,
R = MeO, R′ = morpholino; VI, XVI, R = Me2N, R′ = 3-O2NC6H4O; VII, XVII; R = Me2N, R′ = 4-MeC6H4O; VIII, XVIII,
R = pyrrolidin-1-yl, R′ = PhO; IX, XIX, R = pyrrolidin-1-yl, R′ = morpholino; X, XX, R = R′ = Me2N.
452

TRANSFORMATION OF TRINITROMETHYL GROUP INTO CYANO:
453
Scheme 2.
O2N
Ht
NO2
O2N
NO2
δ+
N
O2N
Ht
NO2
NO
δ–
O
PPh3
O
PPh3
N
O
Ht
–Ph3P=O
O
R'
Ht =
.
N
N
R
N
nating, and the biphilic attack becomes mostly electro-
philic. Here, the transition state is similar to that as-
sumed for the reactions with tertiary amines [12].
Thus we have described a novel procedure for the
synthesis of 1,3,5-triazinecarbonitriles having alkoxy,
aroxy, and amino substituents in the ring via trans-
formation of the corresponding trinitromethyl-1,3,5-tri-
azines by the action of triphenylphosphine. Undoubt-
edly, studies on reactions of triphenylphosphine with
trinitromethyl derivatives of the aromatic, aliphatic,
and heterocyclic series attract strong interest.
Elimination of triphenylphosphine oxide with
formation of dinitro(nitroso)methyl-1,3,5-triazine is
likely to be the rate-determining stage since only initial
trinitromethyl derivatives I–X and 1,3,5-triazinecarbo-
nitriles XI–XX can be detected in the reaction mixture
(TLC data). The dinitro(nitroso)methyl derivative thus
formed (cf. [13]) quickly loses two nitro groups (as
nitrogen dioxide) to afford 1,3,5-triazinecarbonitrile
oxide (Scheme 3).
EXPERIMENTAL
The progress of reactions was monitored by thin-
layer chromatography on Silufol UV-254 plates. The
IR spectra were recorded on an Avatar spectrophotom-
eter from samples pelleted with KBr or thin films
Scheme 3.
O2N
Ht
NO2
NO
Ht
C
N
O
+
2NO2
1
(XI–XIII). The H NMR spectra were measured on
a Bruker AM-300 spectrometer (300 MHz) using tetra-
methylsilane as internal reference. Compounds I–III
were prepared according to the procedure reported in
[17], and 1,3,5-triazines IV–X were synthesized as
described in [4].
Ph3P
+
NO2
Ph3P=O
+
NO
The reaction with nitrogen dioxide requires 2 equiv
of triphenylphosphine (a part of NO2 has no time to
react with triphenylphosphine, so that it evolves as
brown vapor over the surface of toluene) [14, 15]. The
next step is fast reaction of 1,3,5-triazinecarbonitrile
oxide with the fourth molecule of triphenylphosphine
with formation of triphenylphosphine oxide and final
1,3,5-triazinecarbonitrile XI–XX (Scheme 4); the rate
of this reaction is higher than the rate of dimerization
of 1,3,5-triazinecarbonitrile oxide to 3,4-bis(1,3,5-tri-
azin-2-yl)-1,2,5-oxadiazole N-oxide [16] (the latter
was not detected in the reaction mixture by TLC). The
proposed scheme is the most consistent with our ex-
perimental results and available published data on the
mechanisms of particular reaction steps.
4,6-Substituted 1,3,5-triazine-2-carbonitriles XI–
XX (general procedure). Triphenylphosphine, 10.48 g
(0.04 mol), was added in portions over a period of
1–1.5 h to a solution of 0.01 mol of trinitromethyl-
1,3,5-triazine I–X in 40 ml of toluene under stirring at
20–25°C. The mixture was stirred at 20–25°C until
the initial 1,3,5-triazine disappeared (~0.5 h), the pre-
cipitate was filtered was filtered off, the solvent was
distilled off from the filtrate under reduced pressure,
and the residue was subjected to column chromatog-
raphy on silica gel using dichloroethane as eluent to
isolate 1,3,5-triazinecarbonitriles XI–XX.
Scheme 4.
4,6-Dimethoxy-1,3,5-triazine-2-carbonitrile (XI).
Yield 65%, light yellow oily substance. IR spectrum, ν,
cm–1: 3012, 2954, 2927, 2887, 2852, 2252, 1564, 1535,
1517, 1469, 1403, 1367, 1251, 1236, 1211, 1105, 1078,
1058, 987, 923, 819, 715, 698. H NMR spectrum, δ,
ppm: 4.12 s (6H, OCH3). Found, %: C 43.30; H 3.75;
Ht
Ht
N
N
O
O
C
Ht
C
N
O
1
Ph3P
Ht
N
–Ph3P=O
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 44 No. 3 2008

BAKHAREV et al.
454
N 33.64. C6H6N4O2. Calculated, %: C 43.38; H 3.64;
N 33.72.
1604, 1573, 1498, 1425, 1392, 1355, 1245, 1213, 1197,
1166, 1064, 1012, 817, 802. H NMR spectrum, δ,
1
ppm: 2.37 s (3H, CH3), 3.06 s and 3.20 s (3H each,
4,6-Diisopropoxy-1,3,5-triazine-2-carbonitrile
(XII). Yield 63%, light yellow oily substance. IR spec-
trum, ν, cm–1: 2985, 2939, 2877, 2252, 1560, 1535,
1494, 1411, 1375, 1321, 1228, 1182, 1145, 1095, 1035,
NCH3, Δν = 42 Hz), 7.04 d and 7.18 d (4H, Harom
,
J = 3.2 Hz). Found, %: C 61.10; H 5.02; N 27.51.
C13H13N5O. Calculated, %: C 61.16; H 5.13; N 27.43.
1
902, 819. H NMR spectrum, δ, ppm: 1.44 d (12H,
4-Phenoxy-6-(pyrrolidin-1-yl)-1,3,5-triazine-2-
carbonitrile (XVIII). Yield 64%, mp 102–104°C. IR
spectrum, ν, cm–1: 3066, 2975, 2929, 2881, 2252,
1602, 1567, 1523, 1484, 1382, 1338, 1249, 1199, 1000,
CH3, J = 7.4 Hz), 5.37 m (2H, OCH). Found, %:
C 53.97; H 6.42; N 25.12. C10H14N4O2. Calculated, %:
C 54.04; H 6.35; N 25.21.
1
962, 908, 806, 773, 694. H NMR spectrum, δ, ppm:
Dimethyl 3,3′-(6-cyano-1,3,5-triazine-2,4-diyldi-
oxy)dibenzoate (XIII). Yield 59%, light yellow sub-
stance. IR spectrum, ν, cm–1: 3077, 3002, 2954, 2846,
2254, 1724, 1591, 1548, 1486, 1444, 1371, 1295, 1268,
1224, 1201, 1105, 1076, 1020, 1002, 938, 879, 815,
1.92 m (4H, CH2CH2), 3.45 t and 3.59 t (4H, CH2N-
CH2, J = 4.7 Hz), 7.13–7.54 m (5H, C6H5). Found, %:
C 63.00; H 4.82; N 26.13. C14H13N5O. Calculated, %:
C 62.91; H 4.91; N 26.20.
1
4-Morpholino-6-(pyrrolidin-1-yl)-1,3,5-triazine-
2-carbonitrile (XIX). Yield 75%, mp 129–132°C. IR
spectrum, ν, cm–1: 3004, 2973, 2921, 2879, 2850,
2252, 1560, 1508, 1492, 1479, 1440, 1342, 1307, 1251,
1220, 1110, 1068, 1020, 997, 977, 858, 798, 628, 539.
1H NMR spectrum, δ, ppm: 1.94 m (4H, CH2CH2),
3.50 t and 3.57 t (4H, CH2NCH2, J = 4.5 Hz), 3.73 t
and 3.88 t (8H, NCH2CH2O, J = 5.2 Hz). Found, %:
C 55.34; H 6.32; N 32.20. C12H16N6O. Calculated, %:
C 55.37; H 6.20; N 32.29.
796, 761, 727, 690, 676. H NMR spectrum, δ, ppm:
3.94 s (6H, OCH3); 7.32 d, 7.48 t, 7.79 s, and 7.96 d
(8H, C6H4). Found, %: C 59.21; H 3.51; N 13.85.
C20H14N4O6. Calculated, %: C 59.12; H 3.47; N 13.89.
4-Methoxy-6-(pyrrolidin-1-yl)-1,3,5-triazine-2-
carbonitrile (XIV). Yield 74%, mp 87–89°C. IR spec-
trum, ν, cm–1: 3031, 2985, 2956, 2927, 2885, 2248,
1602, 1567, 1506, 1473, 1457, 1371, 1342, 1243, 1226,
1182, 1160, 1120, 1074, 970, 914, 869, 802, 721, 541,
1
526. H NMR spectrum, δ, ppm: 1.93 t (4H, CH2CH2,
4,6-Bis(dimethylamino)-1,3,5-triazine-2-carbo-
nitrile (XX). Yield 59%, mp 136–138°C. IR spectrum,
ν, cm–1: 2925, 2873, 2796, 2250, 1592, 1564, 1488,
1405, 1396, 1355, 1311, 1195, 1047, 1018, 958, 848,
J = 4.5 Hz), 3.52 t (4H, CH2NCH2, J = 4.5 Hz), 3.91 s
(3H, OCH3). Found, %: C 52.76; H 5.47; N 34.15.
C9H11N5O. Calculated, %: C 52.67; H 5.40; N 34.13.
4-Methoxy-6-morpholino-1,3,5-triazine-2-carbo-
nitrile (XV). Yield 70%, mp 118–119°C. IR spectrum,
ν, cm–1: 3008, 2971, 2915, 2869, 2248, 1581, 1569,
1502, 1475, 1448, 1384, 1357, 1309, 1282, 1265, 1234,
1114, 1070, 1006, 865, 806, 538. 1H NMR spectrum, δ,
ppm: 3.73 m (4H, CH2NCH2), 3.87 m (4H, CH2OCH2),
4.00 s (3H, OCH3). Found, %: C 48.73; H 5.11;
N 31.72. C9H11N5O2. Calculated, %: C 48.86; H 5.01;
N 31.66.
1
798. H NMR spectrum, δ, ppm: 3.00 s and 3.09 s
(3H each, NCH3, Δν = 32 Hz). Found, %: C 50.12;
H 6.36; N 43.75. C8H12N6. Calculated, %: C 49.99;
H 6.29; N 43.72.
REFERENCES
1. Shastin, A.V., Godovikova, T.I., Golova, S.P., Khmel’-
nitskii, L.I., and Korsunskii, B.L., Khim. Geterotsikl.
Soedin., 1995, p. 674.
2. Shastin, A.V., Godovikova, T.I., Golova, S.P., Povo-
rin, M.V., Dmitriev, D.E., Dekaprilevich, M.O., Strelen-
ko, Yu.A., Struchkov, Yu.T., Khmel’nitskii, L.I., and Kor-
sunskii, B.L., Khim. Geterotsikl. Soedin., 1995, p. 679.
4-Dimethylamino-6-(3-nitrophenoxy)-1,3,5-tri-
azine-2-carbonitrile (XVI). Yield 70%, mp 160–
162°C. IR spectrum, ν, sm–1: 3103, 2927, 2854, 2255,
1606, 1577, 1533, 1504, 1471, 1417, 1388, 1349, 1265,
1205, 1064, 1014, 966, 892, 869, 819, 804, 754, 719,
663. 1H NMR spectrum, δ, ppm: 3.09 s and 3.24 s (6H,
NCH3, Δν = 45 Hz), 7.50–7.65 m and 8.05–8.20 m
(4H, m-C6H4). Found, %: C 50.43; H 3.60; N 29.48.
C12H10N6O3. Calculated, %: C 50.35; H 3.52; N 29.36.
3. Shastin, A.V., Godovikova, T.I., and Korsunskii, B.L.,
Khim. Geterotsikl. Soedin., 2003, p. 400.
4. Bakharev, V.V. and Gidaspov, A.A., Izv. Samarsk. Nauch.
Tsentra Ross. Akad. Nauk, Khim. Khim. Tekhnol., 2004,
p. 190.
4-Dimethylamino-6-(4-methylphenoxy)-1,3,5-tri-
azine-2-carbonitrile (XVII). Yield 72%, mp 121–
123°C. IR spectrum, ν, cm–1: 3037, 2931, 2881, 2250,
5. Bakharev, V.V., Gidaspov, A.A., and Kachanovskaya, E.V.,
Izv. Samarsk. Nauch. Tsentra Ross. Akad. Nauk, Khim.
Khim. Tekhnol., 2003, p. 112.
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 44 No. 3 2008

TRANSFORMATION OF TRINITROMETHYL GROUP INTO CYANO:
455
12. Kirby, A.J. and Warren, S.G., The Organic Chemistry of
Phosphorus, Amsterdam: Elsevier, 1967. Translated
under the title Organicheskaya khimiya fosfora,
Moscow: Mir, 1971, pp. 87, 103.
13. Benderskii, V.A., Vol’pin, M.E., Zamaraev, K.I., and
Zolotov, Yu.A., Izv. Ross. Akad. Nauk, Ser. Khim., 1993,
p. 147.
6. Bakharev, V.V., Gidaspov, A.A., Ekimova, E.V., and
Galkina, M.V., Materialy dokladov Mezhdunarodnoi
nauchno-tekhnicheskoi
i metodicheskoi konferentsii
“Sovremennye problemy tekhnicheskoi khimii” (Proc.
Int. Scientific and Methodical Conf. “Current Problems
in Technical Chemistry), December 22–24, 2004,
Kazan: Kazan. Gos. Tekhnol. Univ., 2004, p. 273.
14. Horner, L. and Jurgeleit, W., Justus Liebigs Ann. Chem.,
7. Bellamy, A.J., Latypov, N.V., and Goede, P., J. Chem.
Res., Synop., 2003, p. 529.
1955, vol. 591, p. 138.
15. Cox, J.R. and Westheimer, F.H., J. Am. Chem. Soc.,
1958, vol. 80, p. 5441.
16. Bakharev, V.V., Gidaspov, A.A., and Peresedova, E.V.,
8. Urpf, F. and Vilarrasa, J., Tetrahedron Lett., 1990,
vol. 31, p. 7497.
9. Burgess, H. and Donnelly, J.A., Tetrahedron, 1991,
Khim. Geterotsikl. Soedin., 2006, p. 635.
vol. 47, p. 111.
17. Gidaspov, A.A., Khimiya i biologicheskaya aktivnost’
azotsoderzhashchikh geterotsiklov (Chemistry and Bio-
logical Activity of Nitrogen-Containing Heterocycles),
Moscow: Mezhdunar. Fond “Nauchnoe partnerstvo,”
2006, vol. 2, p. 86.
10. Coutouli-Argyropoulou, E., Tetrahedron Lett., 1984,
vol. 25, p. 2029.
11. Trippett, S. and Walker, D.M., J. Chem. Soc., 1960,
p. 2976.
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 44 No. 3 2008