E. Menteşe, M. Özil, Ş. A. Karaoğlu, and B. Kahveci
Vol 000
IR (KBr) (νmax/cm−1): 705, 690 (monosubstituted arom.), 1600
(C N), 1701 (C O); H‐NMR (DMSO‐d6) δ ppm: 1.34 (9H, s,
2,4‐Dihydro‐4‐[4‐(tert‐butyl)phenyl]‐5‐[4‐(methyl)benzyl]‐
3H‐1,2,4‐triazol‐3‐one (2f). Yield: 85%, m.p. 186–188°C; IR
(KBr) (νmax/cm−1): 805 (1,4‐disubstituted arom.), 1582 (C N),
1703 (C O), 3169 (N H); 1H‐NMR (DMSO‐d6) δ ppm: 1.28
(9H, s, CH3), 2.20 (3H, s, CH3), 3.71 (2H, s, CH2), 6.79 (quasi
d, AA′ part of AA′XX′ system, J = 7.8 Hz, 2H, Ar‐H), 6.99
(quasi d, AA′ part of AA′XX′ system, J = 7.8 Hz, 2H, Ar‐H),
7.10 (quasi d, AA′ part of AA′XX′ system, J = 8.6 Hz, 2H, Ar‐H),
7.45 (quasi d, AA′ part of AA′XX′ system, J = 8.6 Hz, 2H,
Ar‐H), 11.69 (1H, s, NH); 13C NMR (50 MHz, DMSO‐d6): 21.28,
31.72, 32.18, 35.12, 126.64, 127.69, 129.16, 129.48, 130.91,
132.69, 136.29, 146.87, 151.74 (C N), 155.18 (C O). Anal. Calcd.
for C20H23N3O: C, 74.74; H, 7.21; N, 13.07. Found: C, 74.71; H,
7.23; N, 13.05.
General procedure for synthesis of (3a‐f). The compounds
2a‐f (0.01 mol), benzyl chloride (0.013 mol), DMF (10mL),
and K2CO3 (0.04mol) were added in a 35‐mL closed vessel.
The mixture was stirred and microwave was irradiated with
pressure control at 170°C for 4 min (hold time) at 300 W
maximum power. After the completion of the reaction (TLC
monitoring AcOEt/hexane 3:1), the mixture was poured into the
water and allowed to stand. The precipitate was filtered and
recrystallized from ethyl acetate‐petroleum ether (1:1).
2‐Benzyl‐2,4‐dihydro‐4‐[4‐(tert‐butyl)phenyl]‐5‐methyl‐
3H‐1,2,4‐triazol‐3‐one (3a). Yield: 82%, m.p. 128–129°C; IR
(KBr) (νmax/cm−1): 740, 659 (monosubstituted arom.), 1581
(C N), 1707 (C O); 1H‐NMR (DMSO‐d6) δ ppm: 1.34 (9H, s,
CH3), 2.10 (3H, s, CH3), 4.90 (2H, s, CH2), 7.25–7.67 (9H, m,
Ar); 13C NMR (50 MHz, DMSO‐d6): 13.10, 31.10, 34.17, 49.18,
126.70, 126.96, 127.50, 128.40, 130.61, 134.70, 146.20 (C N),
152.13 (C O). Anal. Calcd. for C20H23N3O: C, 74.74; H, 7.21; N,
13.07. Found: C, 74.69; H, 7.22; N, 13.09.
2‐Benzyl‐2,4‐dihydro‐4‐[4‐(tert‐butyl)phenyl]‐5‐ethyl‐3H‐
1,2,4‐triazol‐3‐one (3b). Yield: 87%, m.p. 122–123°C; IR
(KBr) (νmax/cm−1): 706, 654 (monosubstituted arom.), 1660
(C N), 1707 (C O); 1H‐NMR (DMSO‐d6) δ ppm: 1.10 (3H, t, CH3,
J = 7.2 Hz), 1.35 (9H, s, CH3), 2.40 (2H, q, CH2, J = 7.2 Hz),
4.92 (2H, s, CH2), 6.59–7.65 (9H, m, Ar); 13C NMR (50 MHz,
DMSO‐d6): 19.10, 23.87, 30.90, 31.70, 49.20, 126.23, 126.79,
127.48, 128.14, 128.44, 130.60, 134.67, 146.91 (C N), 152.98
(C O). C21H25N3O: C, 75.19; H, 7.51; N, 12.53. Found: C,
75.21; H, 7.55; N, 12.50.
1
CH3), 2.19 (3H, s, CH3), 3.79 (2H s, CH2), 4.92 (2H, s, CH2),
6.59–7.45 (13H, m, Ar); 13C NMR (50 MHz, DMSO‐d6):21.55,
31.71, 32.37, 35.18, 51.01, 125.17, 126.71, 126.90, 127.78,
128.01, 128.23, 128.89, 129.27, 128.01, 128.23, 128.89, 129.27,
129.98, 135.38, 137.78, 137.96, 146.70 (C N), 153.57 (C O).
C27H29N3O: C, 78.80; H, 7.10; N, 10.21. Found: C, 78.81; H,
7.14; N, 10.18.
2‐Benzyl‐2,4‐dihydro‐4‐[4‐(tert‐butyl)phenyl]‐5‐[4‐(methyl)
benzyl]‐3H‐1,2,4‐triazol‐3‐one (3f). Yield: 93%, m.p. 85°C; IR
(KBr) (νmax/cm−1): 708, 665 (monosubstituted arom.), 1590
(C N), 1709 (C O); 1H‐NMR (DMSO‐d6) δ ppm: 1.34 (9H, s,
CH3), 2.20 (3H, s, CH3), 3.78 (2H, s, CH2), 4.90 (2H, s, CH2),
6.60–7.58 (13H, m, Ar); 13C NMR (50 MHz, DMSO‐d6): 21.70,
30.80, 31.10, 35.40, 51.10,125.91, 126.60, 127.80, 127.90,
128.40, 128.70, 130.01, 132.14, 132.40 148.53 (C N), 152.17
(C O). C27H29N3O: C, 78.80; H, 7.10; N, 10.21. Found: C,
78.85; H, 7.10; N, 10.22.
General procedure for synthesis of (4a‐f). The compound
2a‐f (0.01 mol) and acetic anhydride (2 mL) were added in a
35‐mL closed vessel. The mixture was heated under microwave
irradiation with pressure control at 160°C for 5min (hold time)
at 150 W maximum power. After the addition of absolute
ethanol (20 mL), the mixture was heated under microwave
irradiation with pressure control at 80°C for 5 min (hold time).
At the end of the reaction (TLC monitoring AcOEt/hexane 3:1),
the resulting solution was evaporated at 40–45°C in vacua and
crystallized from ethanol‐water (1:2).
2‐Acetyl‐2,4‐dihydro‐4‐[4‐(tert‐butyl)phenyl]‐5‐methyl‐
3H‐1,2,4‐triazol‐3‐one (4a). Yield: 92%, m.p. 138–139°C; IR
(KBr) (νmax/cm−1): 830 (1,4‐disubstituted arom.), 1610 (C N),
1
1727, 1780 (C O); H‐NMR (CDCl3‐d6) δ ppm: 1.38 (9H, s,
CH3), 2.20 (3H, s, CH3), 2.74 (3H, s, CH3), 7.24 (quasi d,
AA′ part of AA′XX′ system, J = 8.6 Hz, 2H, Ar‐H), 7.54
(quasi d, AA′ part of AA′XX′ system, J = 8.6 Hz, 2H, Ar‐H);
13C NMR (50 MHz, DMSO‐d6): 12.20, 30.87, 34.44, 34.48,
126.23, 126.89, 129.22, 146.60, 150.65 (C N), 151.65,
166.09 (2 C O). C15H19N3O2: C, 65.91; H, 7.01; N, 15.37.
Found: C, 65.92; H, 7.00; N, 15.39.
2‐Acetyl‐2,4‐dihydro‐4‐[4‐(tert‐butyl)phenyl]‐5‐ethyl‐3H‐
1,2,4‐triazol‐3‐one (4b). Yield: 90%, m.p. 95–96°C; IR (KBr)
(νmax/cm−1): 826 (1,4‐disubstituted arom.), 1601 (C N), 1730,
1769 (C O); 1H‐NMR (CDCl3‐d6) δ ppm: 1.17 (3H, t, CH3,
J = 7.4 Hz), 1.38 (9H, s, CH3), 2.47(2H, q, CH2, J = 7.4 Hz),
2.74 (3H, s, CH3), 7.38 (quasi d, AA′ part of AA′XX′ system,
J = 8.6 Hz, 2H, Ar‐H), 7.57 (quasi d, AA′ part of AA′XX′ system,
J = 8.6 Hz, 2H, Ar‐H); 13C NMR (50 MHz, DMSO‐d6): 19.19,
23.38, 30.86, 31.17, 34.44, 126.29, 126.80, 127.11, 129.14,
150.31 (C N), 151.80, 166.02 (2 C O). C16H21N3O2: C, 66.88; H,
7.37; N, 14.62. Found: C, 66.90; H, 7.35; N, 14.63.
2‐Benzyl‐2,4‐dihydro‐4‐[4‐(tert‐butyl)phenyl]‐5‐phenyl‐
3H‐1,2,4‐triazol‐3‐one (3c). Yield: 95%, m.p. 171–172°C; IR
(KBr) (νmax/cm−1): 710, 669 (monosubstituted arom.), 1606
1
(C N), 1714 (C O); H‐NMR (DMSO‐d6) δ ppm: 1.35 (9H, s,
CH3), 4.90 (2H, s, CH2), 6.90–7.60 (14H, m, Ar); 13C NMR
(50 MHz, DMSO‐d6): 31.60, 35.20, 50.01, 125.27, 126.70,
128.01, 128.24, 128.80, 129.30, 129.90, 135.17, 137. 40, 137.
96, 146.20 (C N), 152.13 (C O). C25H25N3O: C, 78.30; H,
6.57; N, 10.96. Found: C, 78.32; H, 6.55; N, 10.94.
2‐Benzyl‐2,4‐dihydro‐4‐[4‐(tert‐butyl)phenyl]‐5‐benzyl‐
3H‐1,2,4‐triazol‐3‐one (3d). Yield: 90%, m.p. 132–133°C; IR
(KBr) (νmax/cm−1): 704, 690 (monosubstituted arom.), 1587 (C N),
1706 (C O); 1H‐NMR (DMSO‐d6) δ ppm: 1.34 (9H, s, CH3), 3.82
(2H, s, CH2), 4.92 (2H, s, CH2), 6.85–7.47 (14H, m, Ar); 13C
NMR (50 MHz, DMSO‐d6): 30.88, 31.59, 34.34, 50.14, 125.91,
126.56, 126.89, 127.40, 128.14, 128.44, 130.01, 134.70, 136.91,
145.01 (C N), 152.73 (C O). C26H27N3O: C, 78.56; H, 6.85; N,
10.57. Found: C, 78.50; H, 6.85; N, 10.58.
2‐Acetyl‐2,4‐dihydro‐4‐[4‐(tert‐butyl)phenyl]‐5‐phenyl‐3H‐
1,2,4‐triazol‐3‐one (4c). Yield: 93%, m.p. 165–166°C; IR (KBr)
(νmax/cm−1): 822 (1,4‐disubstituted arom.), 1650 (C N), 1736,
1780 (C O); 1H‐NMR (CDCl3‐d6) δ ppm: 1.36 (9H, s, CH3),
2.74 (3H, s, CH3) 7.10–7.47 (9H, m, Ar); 13C NMR (50 MHz,
DMSO‐d6): 24.31, 31.66, 35.22, 126.42, 126.74, 126.95, 127.88,
128.19, 128.26, 128.91, 129.20, 129.32, 130.78, 131.62, 147.82
(C N), 152.48, 167.17 (2 C O). C20H21N3O2: C, 71.62; H, 6.31;
N, 12.53. Found: C, 71.60; H, 6.33; N, 12.55.
2‐Acetyl‐2,4‐dihydro‐4‐[4‐(tert‐butyl)phenyl]‐5‐benzyl‐
3H‐1,2,4‐triazol‐3‐one (4d). Yield: 95%, m.p. 112–113°C;
2‐Benzyl‐2,4‐dihydro‐4‐[4‐(tert‐butyl)phenyl]‐5‐[3‐(methyl)
benzyl]‐3H‐1,2,4‐triazol‐3‐one (3e). Yield: 95%, m.p. 105–107°C;
Journal of Heterocyclic Chemistry
DOI 10.1002/jhet