264
M. A. Zolfigol et al.
CDCl3): ꢁ ¼ 3.85 (s, 3H), 6.97–7.38 (m, 4H) ppm; 13C NMR
(22.5 MHz, CDCl3): ꢁ ¼ 55.6, 115.2, 125.6, 198.8 ppm.
4-(4-tert-Butylphenyl)-4H-1,2,4-triazole-3,5-dione (2k,
Experimental
General Procedure
C12H13N3O2): red crystalline solid, mp 122–126ꢁC; IR (KBr):
Chemicals were purchased from Fluka, Merck, and Aldrich
chemical companies. Yields refer to isolated pure products.
The oxidation products were characterized by comparison of
their spectral (IR and 1H NMR) and physical data with
authentic samples which were produced by other reported
procedures [12a]. Tribromoisocyanuric acid (TBCA) was pre-
pared according to a recently reported procedure by De Mattos
et al. [11b]. Urazoles and bisurazoles [7, 8], hexamethylene-
tetramine-bromine (HMTAB) (I) [10a], DABCO-bromine (II)
[10b], and 1,2-(dipyridiniumditribromide)ethane (DPTBE)
(III) [10c] were synthesized according to previously re-
ported procedures.
ꢀꢀ¼ 2962, 1788, 1714, 1518, 1407, 1185cmꢃ1
;
1H NMR
(90 MHz, CDCl3): ꢁ ¼ 1.28 (s, 9H), 7.33 (m, 4H) ppm; 13C
NMR (22.5 MHz, CDCl3): ꢁ ¼ 31.2, 34.9, 123.7, 126.9, 152.9,
157.9 ppm.
4-(Naphth-1-yl)-4H-1,2,4-triazole-3,5-dione (2l, C12H7N3O2):
brown crystalline solid, mp 109–111ꢁC; IR (KBr): ꢀꢀ¼ 2923,
1
1715, 1417, 770 cmꢃ1; H NMR (90MHz, CDCl3): ꢁ ¼ 6.94–
7.83 (m) ppm; 13C NMR (22.5 MHz, CDCl3): ꢁ ¼ 119.3, 125.7,
126.4, 127.6, 128.6, 129.6, 130.2, 138.5, 139.7, 148.5, 149.2 ppm.
Note: Spectral data of previously reported triazolinediones
see Ref. [12a].
Oxidation of 4,40-(4,40-Diphenylmethylene)bisurazole (3b) to
Bis(p-(3,5-dioxo-1,2,4-triazoline-4-yl)phenyl)methane (4b):
A General Procedure [for Applying HMTAB (I),
Acknowledgement
DABCO-bromine (II) and TBCA (IV)]
Financial support for this work was provided by the research
affairs of Bu-Ali Sina University, Hamadan, Iran.
A mixture of 0.366g 3b (1mmol), and reagent in CH2Cl2
(10 cm3) was stirred for the specified time (molar ratio of
reagents have been indicated in Table 1). Then the reaction
mixture was filtered and the residue was washed with CH2Cl2
(2ꢂ10 cm3). Dichloromethane was removed by using a distil-
lation apparatus and a water-bath (40–50ꢁC). A crystalline
pink solid (4b) is obtained in good to excellent yields. Mp
182–185ꢁC (Ref. [7] 185ꢁC).
See these compounds are sensitive to light, heat, alcohols,
ethers, transition metals, and any other nucleophiles. Also,
they are very volatile so that, if the temperature rises over
50ꢁC in the course of removing of CH2Cl2, some TADs are
removed with the solvent simultaneously (dichloromethane
was evaporated with simple distillation). Therefore, the tem-
perature must be controlled. Dichloromethane is the best sol-
vent for the synthesis of this class of compounds.
References
[1] a) Chehardoli G (2006) Synlett: 2154 and references
cited therein; b) Mallakpour SE, Butler GB, Aghabozorg
H, Palenik GJ (1985) Macromolecules 18: 342
[2] a) Zolfigol MA, Choghamarani AG, Shahamirian M,
Safaiee M, Mohammadpoor-Baltork I, Mallakpour SE,
Abdollahi-Alibeik M (2005) Tetrahedron Lett 46:
5581; b) Zolfigol MA, Azarifar D, Mallakpour SE,
Mohammadpoor-Baltork I, Forghaniha A, Maleki B,
Abdollahi-Alibeik M (2006) Tetrahedron Lett 47:
833; c) Christoforou A, Nicolaou G, Elemes Y (2006)
Tetrahedron Lett 47: 9211
[3] Stickler JC, Pirkle WH (1966) J Org Chem 31: 3444
[4] Read G, Richardson NR (1996) J Chem Soc Perkin
Trans 1: 167
[5] Arya VP, Shenoy S (1976) Indian J Chem 14B: 883
[6] Warnho H, Wald K (1975) Org Prep Proced Int 7: 251
[7] Mallakpour SE (1992) J Chem Ed 69: 238
[8] Mallakpour SE, Zolfigol MA (1993) J Sci I R Iran 4: 199
[9] a) Zolfigol MA, Bagherzadeh M, Mallakpour SE,
Chehardoli G, Choghamarani AG, Kolvari E, Koukabi
N (2007) Catal Commun 8: 256; b) Bamoniri A, Zolfigol
MA, Mohammadpoor-Baltork I, Mirjalili BF (2006) J
Iran Chem Soc 3: 85; c) Niknam K, Zolfigol MA (2006)
J Iran Chem Soc 3: 59; d) See excellent review:
Firouzabadi H, Jafari AA (2005) J Iran Chem Soc 2:
85; e) Niknam K, Zolfigol MA, Sadabadi T, Nejati A
(2006) J Iran Chem Soc 3: 318; f) Zolfigol MA,
Bagherzadeh M, Niknam K, Shirini F, Mohammadpoor-
Baltork I, Choghamarani AG, Baghbanzadeh M (2006) J
Iran Chem Soc 3: 73; g) Salehi P, Zolfigol MA, Shirini F,
Baghbanzadeh M (2006) Curr Org Chem 10: 2171
[10] a) Yavari I, Shaabani A (1994) J Chem Res (S) 274; b)
Heravi MM, Derikvand F, Ghassemzadeh M, Neumuller
B (2005) Tetrahedron Lett 46: 6243; c) Kavala V, Naik S,
Oxidation of 4-Phenylurazole (1f) to 4-Phenyl-1,2,4-
triazoline-3,5-dione (2f): A Typical Procedure [for
DPTBE (III)]
A suspension of 0.177 g 1f (1mmol), DPTBE (III) (0.664 g,
1 mmol), and 5 drops of water were added in dichloromethane
(10 cm3) and the suspension was vigorously stirred for 0.5 h
(Table 1, entry 6). The residue was washed with CH2Cl2
(2ꢂ10 cm3) and filtered. The filtrate was dried over 3 g anhy-
drous Na2SO4, which was filtered off after the appropriate
time. Then the filtrate was passed through a short pad of
silica gel for removing any remaining of reagent residue.
Dichloromethane was removed by using a distillation appara-
tus and a water-bath (40–50ꢁC). The yield was 0.1681 g (95%)
of a crystalline red solid (2f), mp 171–175ꢁC (Ref. [7] 170–
178ꢁC).
Melting Points and Spectral Data for the New
Triazolinediones
4-(4-Methoxyphenyl)-4H-1,2,4-triazole-3,5-dione
C9H7N3O3): dark red crystalline solid, mp 89–93ꢁC; IR (KBr):
ꢀꢀ¼ 2968, 1773, 1515, 1258, 1173cmꢃ1; H NMR (90 MHz,
(2j,
1