6,7-Dihydro-1H,4H-pyrazolo[3,4-d][1,3]oxazines
CDCl3): δ = 1.35 (s, 9 H, tBu), 3.96 (s, 2 H, 8-H), 4.49 (s, 2 H, 6-
H), 4.90 (s, 2 H, 4-H), 7.22–7.34 (m, 6 H, Ar-H), 7.44 (t, J = 7.7 Hz,
2 H, Ar-H), 7.89 (d, J = 7.7 Hz, 2 H, Ar-H) ppm. 13C NMR
(100 MHz, CDCl3): δ = 29.5 (tBu), 32.2 (Cq, tBu), 55.3 (C-8), 64.2
(C-4), 77.9 (C-6), 103.2 (Cq), 122.3, 126.3, 127.5, 128.5, 128.8,
129.1, 136.9 (Cq), 139.5 (Cq), 144.1 (Cq), 156.1 (Cq) ppm. FTIR
ppm. FTIR (KBr): ν = 3056, 2965, 2865, 1598 (C=N), 1576 (C=C),
˜
1509, 1024 (C–O oxazine) cm–1. MS (70 eV, EI): m/z (%) = 365
(100) [M]+, 256 (63), 228 (30), 109 (53) [C7H6F]. C22H24FN3O
(365.19): calcd. C 72.31, H 6.62, N 11.50; found C 72.24, H 6.70,
N 11.39.
3-tert-Butyl-1-phenyl-7-(pyridin-3-ylmethyl)-1,4,6,7-tetrahydropyr-
azolo[3,4-d][1,3]oxazine (16g): Yield: 0.293 g. White solid. 1H NMR
(400 MHz, [D6]DMSO): δ = 1.25 (s, 9 H, tBu), 3.90 (s, 2 H, 8-H),
4.49 (s, 2 H, 6-H), 4.80 (s, 2 H, 4-H), 7.29–7.34 (m, 2 H, Ar-H and
Py-H), 7.48 (t, J = 7.7 Hz, 2 H, Ar-H), 7.58 (d, J = 7.9 Hz, 1 H,
Py-H), 7.77 (d, J = 7.4 Hz, 2 H, Ar-H), 8.36 (d, J = 1.7 Hz, 1 H,
Py-H), 8.47 (dd, J = 4.8, J = 1.7 Hz, 1 H, Py-H) ppm. 13C NMR
(100 MHz, [D6]DMSO): δ = 29.2 (tBu), 32.7 (Cq, tBu), 52.7 (C-8),
63.0 (C-4), 78.1 (C-6), 103.1 (Cq), 122.0, 123.4, 126.5, 129.2, 132.2
(Cq), 135.9, 139.0 (Cq), 143.2 (Cq), 148.7, 149.4, 155.3 (Cq) ppm.
(KBr): ν = 3060, 2964, 2859, 1596 (C=N), 1592 (C=C), 1502, 1023
˜
(C–O oxazine) cm–1. MS (70 eV, EI): m/z (%) = 347 (100) [M]+,
316 (11), 302 (12), 256 (29), 228 (9), 91 (16), 77 (9) [Ph]. C22H25N3O
(347.45): calcd. C 76.05, H 7.25, N 12.09; found C 75.91, H 7.51,
N 12.30.
7-(4-Bromobenzyl)-3-tert-butyl-1-phenyl-1,4,6,7-tetrahydropyrazolo-
[3,4-d][1,3]oxazine (16c): Yield: 0.273 g. White solid. 1H NMR
(400 MHz, CDCl3): δ = 1.29 (s, 9 H, tBu), 3.85 (s, 2 H, 8-H), 4.42
(s, 2 H, 6-H), 4.84 (s, 2 H, 4-H), 7.09 (d, J = 8.1 Hz, 2 H, Ar-H),
7.23 (t, J = 7.1 Hz, 1 H, Ar-H), 7.35–7.53 (m, 4 H, Ar-H), 7.79 (d,
J = 7.3 Hz, 2 H, Ar-H) ppm. 13C NMR (100 MHz, CDCl3): δ =
29.4 (tBu), 33.2 (Cq, tBu), 54.7 (C-8), 64.1 (C-4), 78.1 (C-6), 103.2
(Cq), 121.5 (Cq), 122.4, 126.4, 129.1, 130.3, 131.6, 136.0 (Cq),
FTIR (KBr): ν = 3060, 2965, 2882, 1595 (C=N), 1587 (C=C), 1506,
˜
1022 (C–O oxazine) cm–1. MS (70 eV, EI): m/z (%) = 348 (100) [M]
+, 303 (19), 228 (26), 170 (14), 92 (14) [C6H6N]. C21H24N4O (348.2):
calcd. C 72.39, H 6.94, N 16.08; found C 72.45, H 7.00, N 16.00.
139.4 (Cq), 143.7 (Cq), 156.1 (Cq) ppm. FTIR (KBr): ν = 3059,
˜
3-tert-Butyl-1-phenyl-7-[4-(trifluoromethyl)benzyl]-1,4,6,7-tetra-
hydropyrazolo[3,4-d][1,3]oxazine (16h): Yield: 0.274 g. White solid.
1H NMR (400 MHz, [D6]DMSO): δ = 1.26 (s, 9 H, tBu), 3.97 (s,
2 H, 8-H), 4.48 (s, 2 H, 6-H), 4.83 (s, 2 H, 4-H), 7.27 (t, J = 7.5 Hz,
1 H, Ar-H), 7.45 (br. t, 4 H, Ar-H), 7.67 (d, J = 8.1 Hz, 2 H, Ar-
H), 7.77 (d, J = 7.5 Hz, 2 H, Ar-H) ppm. 13C NMR (100 MHz,
[D6]DMSO): δ = 29.2 (tBu), 32.7 (Cq, tBu), 54.5 (C-8), 63.0 (C-4),
78.1 (C-6), 103.1 (Cq), 121.8, 124.1 (q, J = 271.0 Hz, CF3), 125.1
(q, J = 4.0 Hz), 126.4, 128.2 (q, J = 31.0 Hz, Cq-F), 128.8, 129.2,
138.9 (Cq), 141.6 (Cq), 143.3 (Cq), 155.3 (Cq) ppm. FTIR (KBr):
2960, 2851, 1595 (C=N), 1573 (C=C), 1506, 1012 (C–O oxazine)
cm–1. MS (70 eV, EI): m/z (%) = 427/425 (53/54) [M]+, 256 (100),
228 (50), 171/169 (30/32) [C7H6Br]. C22H24BrN3O (425.11): calcd.
C 61.98, H 5.67, N 9.86; found C 70.01, H 5.72, N 9.75.
3-tert-Butyl-7-(4-methylbenzyl)-1-phenyl-1,4,6,7-tetrahydropyrazolo-
[3,4-d][1,3]oxazine (16d): Yield: 0.292 g. White solid. 1H NMR
(400 MHz, [D6]DMSO): δ = 1.26 (s, 9 H, tBu), 2.26 (s, 3 H, CH3),
3.85 (s, 2 H, 8-H), 4.44 (s, 2 H, 6-H), 4.80 (s, 2 H, 4-H), 7.05–7.09
(m, 4 H, Ar-H), 7.26 (t, J = 7.4 Hz, 1 H, Ar-H), 7.43 (t, J = 7.4 Hz,
2 H, Ar-H), 7.76 (d, J = 8.1 Hz, 2 H, Ar-H) ppm. 13C NMR
(100 MHz, [D6]DMSO): δ = 19.9 (CH3), 28.7 (tBu), 32.2 (Cq, tBu),
54.3 (C-8), 62.7 (C-4), 77.4 (C-6), 102.3 (Cq), 121.5, 125.6, 127.7,
128.4 (2 C), 133.1 (Cq), 136.0 (Cq), 138.9 (Cq), 143.4 (Cq), 154.9
ν = 3053, 2967, 2854, 1618 (C=N), 1600 (C=C), 1509, 1016 (C–O
˜
oxazine) cm–1. MS (70 eV, EI): m/z (%) = 415 (100) [M]+, 370 (24),
170 (31), 159 (24) [C8H6F3]. C23H24F3N3O (415.19): calcd. C 66.49,
H 5.82, N 10.11; found C 66.60, H 5.93, N 9.93.
(Cq) ppm. FTIR (KBr): ν = 3048, 2962, 2857, 1594 (C=N), 1576
˜
(C=C), 1506, 1023 (C–O oxazine) cm–1. MS (70 eV, EI): m/z (%) =
361 (51) [M]+, 256 (16), 105 (100) [C8H9]. C23H27N3O (361.22):
calcd. C 76.42, H 7.53, N 11.62; found C 76.21, H 7.51, N 11.50.
3-tert-Butyl-7-(4-nitrobenzyl)-1-phenyl-1,4,6,7-tetrahydropyrazolo-
[3,4-d][1,3]oxazine (16i): Yield: 0.269 g. White solid. 1H NMR
(400 MHz, [D6]DMSO): δ = 1.26 (s, 9 H, tBu), 4.02 (s, 2 H, 8-H),
4.50 (s, 2 H, 6-H), 4.83 (s, 2 H, 4-H), 7.26 (t, J = 7.4 Hz, 1 H, Ar-
H), 7.44 (t, J = 8.3 Hz, 2 H, Ar-H), 7.51 (d, J = 8.9 Hz, 2 H, Ar-
H), 7.75 (d, J = 7.4 Hz, 2 H, Ar-H), 8.17 (d, J = 8.9 Hz, 2 H, Ar-
H) ppm. 13C NMR (100 MHz, [D6]DMSO): δ = 29.2 (tBu), 32.8
(Cq, tBu), 54.5 (C-8), 63.0 (C-4), 78.4 (C-6), 103.1 (Cq), 121.9,
123.5, 126.4, 129.0, 129.1, 138.9 (Cq), 143.1 (Cq), 144.8 (Cq), 146.8
3-tert-Butyl-7-(2,3-dimethoxybenzyl)-1-phenyl-1,4,6,7-tetrahydropyr-
azolo[3,4-d][1,3]oxazine (16e): Yield: 0.278 g. White solid. 1H NMR
(400 MHz, [D6]DMSO): δ = 1.26 (s, 9 H, tBu), 3.54 (s, 3 H, OCH3),
3.77 (s, 3 H, OCH3), 3.88 (s, 2 H, 8-H), 4.44 (s, 2 H, 6-H), 4.82 (s,
2 H, 4-H), 6.91 (d, J = 7.7 Hz, 1 H, Ar-H), 6.96 (d, J = 8.3 Hz, 1
H, Ar-H), 7.06 (t, J = 7.9 Hz, 1 H, Ar-H), 7.26 (t, J = 7.4 Hz, 1
H, Ar-H), 7.43 (t, J = 8.3 Hz, 2 H, Ar-H), 7.77 (d, J = 7.5 Hz, 2
H, Ar-H) ppm. 13C NMR (100 MHz, [D6]DMSO): δ = 29.2 (tBu),
32.8 (Cq, tBu), 49.0 (C-8), 55.6 (OCH3), 59.9 (OCH3), 63.0 (C-4),
77.9 (C-6), 103.0 (Cq), 112.1, 120.7, 121.6, 123.9, 126.2, 129.0,
129.9 (Cq), 139.1 (Cq), 143.8 (Cq), 146.8 (Cq), 152.2 (Cq), 155.2
(Cq), 155.3 (Cq) ppm. FTIR (KBr): ν = 3048, 2961, 2867, 1597
˜
(C=N), 1581 (C=C), 1527 (NO2), 1503, 1341 (NO2), 1025 (C–O
oxazine) cm–1. MS (70 eV, EI): m/z (%) = 392 (100) [M]+, 256 (41),
228 (24), 170 (25). C22H24N4O3 (392.18): calcd. C 67.33, H 6.16, N
14.28; found C 67.14, H 6.30, N 14.07.
(Cq) ppm. FTIR (KBr): ν = 3050, 2961, 2871, 1595 (C=N), 1576
˜
3-tert-Butyl-7-(4-chlorobenzyl)-1-phenyl-1,4,6,7-tetrahydropyrazolo-
[3,4-d][1,3]oxazine (16j): Yield: 0.276 g. White solid. 1H NMR
(400 MHz, CDCl3): δ = 1.34 (s, 9 H, tBu), 3.92 (s, 2 H, 8-H), 4.47
(s, 2 H, 6-H), 4.89 (s, 2 H, 4-H), 7.19 (d, J = 8.3 Hz, 2 H, Ar-H),
7.25 (t, J = 7.7 Hz, 1 H, Ar-H), 7.28 (d, J = 8.3 Hz, 2 H, Ar-H),
7.43 (t, J = 7.7 Hz, 2 H, Ar-H), 7.84 (d, J = 8.0 Hz, 2 H, Ar-H)
ppm. 13C NMR (100 MHz, CDCl3): δ = 29.4 (tBu), 33.2 (Cq, tBu),
54.6 (C-8), 64.1 (C-4), 78.1 (C-6), 103.2 (Cq), 122.4, 126.5, 128.6,
(C=C), 1503, 1262 (C–O), 1040 (C–O oxazine) cm–1. MS (70 eV,
EI): m/z (%) = 407 (34) [M]+, 151 (100) [C9H11O2], 136 (81), 91
(21), 77 (10) [Ph]. C24H29N3O3 (407.22): calcd. C 70.74, H 7.17, N
10.31; found C 70.52, H 7.30, N 10.20.
3-tert-Butyl-7-(4-fluorobenzyl)-1-phenyl-1,4,6,7-tetrahydropyrazolo-
[3,4-d][1,3]oxazine (16f): Yield: 0.275 g. White solid. 1H NMR
(400 MHz, [D6]DMSO): δ = 1.26 (s, 9 H, tBu), 3.84 (s, 2 H, 8-H),
4.44 (s, 2 H, 6-H), 4.82 (s, 2 H, 4-H), 7.11–7.30 (m, 5 H, Ar-H), 129.1, 130.0, 133.4 (Cq), 135.4 (Cq), 139.4 (Cq), 143.8 (Cq), 156.1
7.48 (t, J = 7.5 Hz, 2 H, Ar-H), 7.78 (d, J = 7.4 Hz, 2 H, Ar-H) (Cq) ppm. FTIR (KBr): ν = 3057, 2961, 2851, 1596 (C=N), 1573
˜
ppm. 13C NMR (100 MHz, [D6]DMSO): δ = 29.2 (tBu), 32.7 (Cq, (C=C), 1506, 1014 (C–O oxazine) cm–1. MS (70 eV, EI): m/z (%) =
tBu), 54.1 (C-8), 63.0 (C-4), 77.6 (C-6), 103.1 (Cq), 115.1 (d, J =
21.0 Hz), 121.8, 126.4, 129.1, 130.2 (d, J = 8.0 Hz), 132.7 (Cq),
139.0 (Cq), 143.5 (Cq), 155.2 (Cq), 161.4 (d, J = 242.0 Hz, Cq-F)
383/381 (24/70) [M]+, 228 (50), 127/125 (24/68) [C7H6Cl].
C22H24ClN3O (381.16): calcd. C 69.19, H 6.33, N 11.00; found C
69.08, H 6.40, N 11.11.
Eur. J. Org. Chem. 2010, 6454–6463
© 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjoc.org
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