Molecules 2021, 26, 3540
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DMSO-d6)
δ
7.1 (CH3), 12.9 (SCH3), 105.5 (Cq), 143.6 (Cq), 145.2 (Cq), 146.6 (CHAr), 155.3
(Cq). HRMS (EI-MS): m/z calcd for C7H8N4OS: 197.0419 [M + H]+, found: 197.0496.
8-Ethyl-2-(methylsulfanyl)pyrazolo[1,5-a][1,3,5]triazin-4(3H)-one (4f). White solid (0.655 g,
65%) obtained from 1f (0.5 g, 4.41 mmol) according to the general procedure; m.p. 188–
190 ◦C; IR (neat)
ν
max: 3498, 3080, 2961, 2873, 2634, 1993, 1761 (CO), 1598, 1563, 1497, 1450,
1353, 1238, 1171, 1065, 1033, 960, 908, 823, 740, 703, 663, 630, 547 cm−1; 1H NMR (300 MHz,
DMSO-d6) 1.20 (t, J = 7.6 Hz, 3H, CH2-CH3), 2.52–2.60 (m, 5H, CH2-CH3 and SCH3),
7.91 (s, 1H, HAr), 12.73 (s, 1H, OH). 13C NMR (75 MHz, DMSO-d6)
12.9 (SCH3), 14.4
δ
δ
(CH2-CH3), 15.5 (CH2-CH3), 112.0 (Cq), 143.7 (Cq), 144.7 (Cq), 145.5 (CHAr), 155.3 (Cq);
HRMS (EI-MS): m/z calcd for C8H10N4OS: 211.0648 [M + H]+, found: 211.0655.
8-Isopropyl-2-(methylsulfanyl)pyrazolo[1,5-a][1,3,5]triazin-4(3H)-one (4g). Pale yellow
solid (0.964 g, 75%) obtained from 1g (0.750 g, 5.69 mmol) according to the general proce-
dure; m.p. 203–205 ◦C; IR (neat)
ν
max: 3079, 2953, 2925, 2865, 2798, 2634, 1759 (CO), 1595,
1572, 1554, 1492, 1448, 1359, 1312, 1242, 1175, 1030, 908, 826, 741, 701, 665, 629, 553 cm−1; 1H
NMR (400 MHz, DMSO-d6) 1.25 (d, J = 7.0 Hz, 6H, 2 CH3-iPr), 2.54 (s, 3H, SCH3), 3.01
(hept, J = 7.0 Hz, 1H, HiPr), 7.91 (s, 1H), 12.73 (s, 1H, OH). 13C NMR (101 MHz, DMSO-d6)
δ
×
δ
12.9 (SCH3), 22.9 (2
×
CH3-iPr), 23.1 (CHiPr), 116.9 (Cq), 143.6 (Cq), 144.1 (Cq), 144.2 (CHAr),
155.0 (Cq). HRMS (EI-MS): m/z calcd for C9H12N4OS: 225.0805 [M + H]+, found: 225.0806.
8-Cyclopropyl-2-(methylsulfanyl)pyrazolo[1,5-a][1,3,5]triazin-4(3H)-one (4h). Beige solid
(0.410 g, 60%) obtained from 1h (0.380 g, 3.08 mmol) according to the general procedure;
m.p. 225–227 ◦C; IR (neat)
ν
max: 3079, 2995, 2883, 2635, 1758 (CO), 1606, 1561, 1504, 1449,
1349, 1313, 1238, 1207, 1167, 1030, 906, 876, 813, 739, 696, 660, 627, 548 cm−1; H NMR
1
(300 MHz, DMSO-d6)
δ
0.77–0.93 (m, 4H, 2
×
CH2-cPr), 1.83 (ddd, J = 16.8, 8.3, 5.2 Hz, 1H,
CHcPr), 2.54 (s, 3H, CH3), 7.79 (s, 1H, HAr), 12.70 (s, 1H, OH). 13C NMR (75 MHz, DMSO-d6)
δ
4.8 (CHcPr), 7.2 (2
×
CH2-cPr), 12.9 (CH3), 112.7 (Cq), 143.5 (Cq), 144.1 (CHAr), 144.6 (Cq),
155.1 (Cq). HRMS (EI-MS): m/z calcd for C9H10N4OS: 223.0348 [M + H]+, found: 223.0661.
8-Cyclobutyl-2-(methylsulfanyl)pyrazolo[1,5-a][1,3,5]triazin-4(3H)-one (4i). White solid
(0.190 g, 55%) obtained from 1i (0.2 g, 1.46 mmol) according to the general procedure; m.p.
222–224 ◦C; IR (neat)
ν
max: 3667, 3080, 2969, 2900, 2634, 2119, 1759 (CO), 1596, 1567, 1497,
1454, 1348, 1240, 1197, 1163, 1053, 988, 906, 822, 739, 665, 629, 546 cm−1; 1H NMR (400 MHz,
DMSO-d6) 1.81–2.03 (m, 4H, CH2-CH2-CH), 2.25 (qd, J = 8.5, 2.7 Hz, 4H, CH2-CH2-CH),
2.55 (s, 3H, SCH3), 3.54 (p, J = 8.7 Hz, 1H, HcBut), 8.00 (s, 1H, HAr), 12.72 (s, 1H, OH). 13
NMR (101 MHz, DMSO-d6)
12.9 (SCH3), 18.4 (2 × CH2-CH2-CH), 29.0 (CHcBut), 29.5
δ
C
δ
(2
×
CH2-CH2-CH), 114.8 (Cq), 143.6 (Cq), 144.2 (Cq), 144.9 (CHAr), 155.3 (Cq). HRMS
(EI-MS): m/z calcd for C10H12N4OS: 237.0805 [M + H]+, found: 237.0809.
2-(Methylsulfanyl)-8-phenyl-pyrazolo[1,5-a][1,3,5]triazin-4(3H)-one (4j). White solid (0.500 g,
◦
65%) obtained from 1j (0.5 g, 2.98 mmol) according to the general procedure; m.p. 277–279 C;
IR (neat)
1173, 1145, 1094, 981, 934, 904, 795, 755, 713, 687, 670, 628, 550, 511 cm−1; 1H NMR (400 MHz,
DMSO-d6) 2.64 (s, 3H, SCH3), 7.25 (t, J = 7.4 Hz, 1H, HAr), 7.42 (t, J = 7.6 Hz, 2H, 2 HAr),
8.03 (d, J = 7.7 Hz, 2H, 2
HAr), 8.53 (s, 1H, HAr), 12.98 (s, 1H, OH). 13C NMR (101 MHz,
DMSO-d6) 13.2 (SCH3), 109.8 (Cq), 125.7 (2 CHAr), 126.4 (CHAr), 128.7 (2 CHAr),
νmax: 3491, 3065, 2890, 2824, 1944, 1756 (CO), 1594, 1559, 1460, 1432, 1356, 1228,
δ
×
×
δ
×
×
131.2 (Cq), 143.5 (Cq), 143.8 (CHAr), 144.1 (Cq), 157.6 (Cq). HRMS (EI-MS): m/z calcd for
C12H10N4OS: 259.0648 [M + H]+, found: 259.0657.
2-(Methylsulfanyl)-8-(p-tolyl)pyrazolo[1,5-a][1,3,5]triazin-4(3H)-one (4k). White solid (0.560 g,
◦
68%) obtained from 1k (0.550 g, 3.02 mmol) according to the general procedure; m.p. > 290 C;
IR (neat)
1228, 1172, 1144, 982, 907, 809, 741, 695, 671, 626, 550, 514 cm−1; 1H NMR (300 MHz, DMSO-d6)
2.31 (s, 3H, SCH3), 2.63 (s, 3H, CH3-Ph), 7.23 (d, J = 7.8 Hz, 2H, 2 HAr), 7.91 (d, J = 8.0 Hz,
2H, 2 13.2
HAr), 8.48 (s, 1H, HAr), 12.95 (s, 1H, OH). 13C NMR (75 MHz, DMSO-d6)
(SCH3), 20.8 (CH3-Ph), 109.9 (Cq), 125.6 (2 CHAr), 128.2 (Cq), 129.3 (2 CHAr), 135.5 (Cq),
νmax: 3486, 3064, 3007, 2884, 1759 (CO), 1595, 1561, 1511, 1455, 1407, 1352, 1316, 1255,
δ
×
×
δ
×
×