Helv. Chim. Acta 2016, 99, 33 – 36
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J ¼ 7.4, 1.7, 1 H); 7.36 (ddd, J ¼ 8.0, 7.4, 1.7, 1 H); 7.47 (dd, J ¼ 7.4, 1.7,
1 H); 7.57 (dd, J ¼ 8.0, 1.7, 1 H).
1 H); 7.29 (d, J ¼ 8.0, 1 H); 7.34 (ddd, J ¼ 8.0, 7.4, 1.1, 1 H); 7.46 (td, J ¼
7.4, 1.1, 1 H); 7.51 (td, J ¼ 7.4, 1.1, 1 H); 7.72 (dd, J ¼ 7.4, 1.1, 1 H).
13C-NMR: 19.47; 22.43; 44.60; 125.03; 125.37; 125.68; 127.56; 127.62;
129.02; 129.81; 130.25; 132.45; 134.80; 135.43; 136.18; 173.06. HR-ESI-
MS: 266.1288 ([M þ H]þ, C16H16N3Oþ; calc. 266.1293). Anal. calc. for
C16H15N3O (265.31): C 72.43, H 5.70, N 15.84; found: C 72.30, H 5.82, N
15.90.
1-[Azido(phenyl)methyl]-2-bromobenzene (1c). Colorless oil. Rf
(CH2Cl2/hexane 1:5) 0.36. IR (neat): 2100. 1H-NMR: 6.16 (s, 1 H); 7.19
(ddd, J ¼ 8.0, 7.4, 1.7, 1 H); 7.30 – 7.38 (m, 6 H); 7.49 (dd, J ¼ 8.0, 1.7,
1 H); 7.57 (dd, J ¼ 8.0, 1.1, 1 H). Anal. calc. for C13H10BrN3 (288.14): C
54.19, H 3.50, N 14.58; found: C 54.07, H 3.68, N 14.28.
1,2,3-Benzotriazin-3(4H)-yl(phenyl)methanone (2a). Representa-
tive Procedure. To a stirred soln. of 1a (0.21 g, 1.0 mmol) in THF at
À 788 was added BuLi (1.6m in hexane, 1.0 mmol) dropwise. After
5 min, a soln. of BzCl (0.14 g, 1.0 mmol) in THF (2 ml) was added
slowly. H2O (20 ml) was then added, and the mixture was warmed to r.t.
and extracted with AcOEt (3 Â 10 ml). The combined extracts were
washed with aq. 10% NaOH, H2O, and brine (10 ml each), then dried
(Na2SO4), and finally concentrated by evaporation. The residual solid
was recrystallized from hexane/CH2Cl2 to give 2a (0.20 g, 83%). Pale-
(4-Chlorophenyl)(4-methyl-1,2,3-benzotriazin-3(4H)-yl)metha-
none (2h). White solid. M.p. 72 – 748 (hexane/CH2Cl2). IR (KBr): 1673.
1H-NMR: 1.39 (d, J ¼ 6.9, 3 H); 5.62 (q, J ¼ 6.9, 1 H); 7.18 (dd, J ¼ 7.4,
1.7, 1 H); 7.42 (d, J ¼ 8.6, 2 H); 7.48 – 7.54 (m, 2 H); 7.68 (d, J ¼ 8.6, 2 H);
7.77 (dd, J ¼ 7.4, 1.1, 1 H). 13C-NMR: 21.93; 45.26; 125.44; 125.56;
127.38; 128.19; 129.06; 131.78; 131.83; 132.56; 136.38; 137.93; 170.29.
HR-ESI-MS: 286.0742 ([M þ H]þ, C15H13ClN3Oþ; calc. 286.0747).
Anal. calc. for C15H12ClN3O (285.73): C 63.05, H 4.23, N 14.71; found: C
62.97, H 4.18, N 14.65.
Ethyl 4-Methyl-1,2,3-benzotriazine-3(4H)-carboxylate (2i). Yellow
oil. Rf (AcOEt/hexane 1:7) 0.27. IR (neat): 1723. 1H-NMR: 1.31 (d, J ¼
6.3, 3 H); 1.43 (t, J ¼ 7.4, 3 H); 4.41 – 4.52 (m, 2 H); 5.34 (q, J ¼ 6.3,
1 H); 7.09 (dd, J ¼ 6.9, 1.7, 1 H); 7.42 – 7.48 (m, 2 H); 7.73 (d, J ¼ 6.9, 2.2,
1 H). 13C-NMR: 14.41; 22.25; 46.34; 63.55; 125.23; 125.28; 127.29;
129.00; 132.13; 136.11; 153.85. HR-ESI-MS: 220.1079 ([M þ H]þ,
C11H14N3Oþ2 ; calc. 220.1086). Anal. calc. for C11H13N3O2 (219.24): C
60.26, H 5.98, N 19.17; found: C 60.26, H 6.04, N 19.06.
1
yellow solid. M.p. 103 – 1058. IR (KBr): 1672. H-NMR: 4.92 (s, 2 H);
7.18 (dd, J ¼ 6.3, 2.3, 1 H); 7.44 – 7.51 (m, 4 H); 7.54 (t, J ¼ 7.4, 1 H); 7.74
(dd, J ¼ 6.9, 2.3, 1 H); 7.78 (dd, J ¼ 6.9, 1.7, 2 H). 13C-NMR: 38.88;
119.26; 126.28; 127.79; 127.91; 129.22; 130.37; 131.69; 132.24; 133.03;
136.29; 171.94. HR-ESI-MS: 238.0973 ([M þ H]þ, C14H12N3Oþ; calc.
238.0980). Anal. calc. for C14H11N3O (237.26): C 70.87, H 4.67, N 17.71;
found: C 70.81, H 4.70, N 17.64.
1,2,3-Benzotriazin-3(4H)-yl(2-chlorophenyl)methanone (2b).
White solid. M.p. 101 – 1028 (hexane/CH2Cl2). IR (KBr): 1687.
1H-NMR: 5.00 (s, 2 H); 7.17 (d, J ¼ 7.4, 1 H); 7.34 – 7.50 (m, 6 H); 7.70
(d, J ¼ 7.4, 1 H). 13C-NMR: 38.59; 118.34; 126.39; 126.62; 128.39;
128.84; 129.31; 129.48; 130.95; 131.33; 132.47; 134.67; 135.76; 170.69.
HR-ESI-MS: 272.0585 ([M þ H]þ, C14H11ClN3Oþ; calc. 272.0590).
Anal. calc. for C14H10ClN3O (271.70): C 61.89, H 3.71, N 15.47; found: C
61.66, H 3.88, N 15.43.
1-(4-Methyl-1,2,3-benzotriazin-3(4H)-yl)ethanone (2j). Beige sol-
1
id. M.p. 52 – 538 (hexane/CH2Cl2). IR (KBr): 1700. H-NMR: 1.28 (d,
J ¼ 6.9, 3 H); 2.58 (s, 3 H); 5.57 (q, J ¼ 6.9, 1 H); 7.10 (dd, J ¼ 6.3, 1.7,
1 H); 7.43 – 7.48 (m, 2 H); 7.73 (dd, J ¼ 6.9, 2.3, 1 H). 13C-NMR: 21.86;
22.66; 44.05; 124.98; 125.64; 127.31; 128.88; 132.21; 136.15; 173.19. HR-
ESI-MS: 190.0975 ([M þ H]þ, C10H12N3Oþ; calc. 190.0980). Anal. calc.
for C10H11N3O (189.21): C 63.48, H 5.86, N 22.21; found: C 63.28, H
5.88, N 22.08.
Ethyl 4-Phenyl-1,2,3-benzotriazine-3(4H)-carboxylate (2k). White
solid. M.p. 75 – 778 (hexane/CH2Cl2). IR (KBr): 1725. 1H-NMR: 1.37 (t,
J ¼ 6.9, 3 H); 4.32 – 4.46 (m, 2 H); 6.30 (s, 1 H); 7.09 (dd, J ¼ 6.9, 1.7,
1 H); 7.18 (d, J ¼ 6.9, 2 H); 7.24 – 7.29 (m, 3 H); 7.41 – 7.47 (m, 2 H); 7.80
(dd, J ¼ 7.4, 1.7, 1 H). 13C-NMR: 14.32; 53.73; 63.73; 122.83; 126.59;
126.68; 127.79; 128.34; 128.84; 129.17; 132.41; 135.38; 141.34; 153.86.
HR-MS (DART): 282.1233 ([M þ H]þ, C16H16N3Oþ2 ; calc. 282.1242).
Anal. calc. for C16H15N3O2 (281.31): C 68.31, H 5.37, N 14.94; found: C
68.21, H 5.41, N 14.76.
Ethyl 1,2,3-Benzotriazine-3(4H)-carboxylate (2c). Pale-yellow sol-
1
id. M.p. 93 – 958 (hexane/CH2Cl2). IR (KBr): 1718. H-NMR: 1.43 (t,
J ¼ 7.4, 3 H); 4.46 (q, J ¼ 7.4, 2 H); 4.76 (s, 2 H); 7.07 (dd, J ¼ 4.6, 3.4,
1 H); 7.41 – 7.44 (m, 2 H); 7.70 (dd, J ¼ 4.6, 4.0, 1 H). 13C-NMR: 14.43;
39.85; 63.66; 119.04; 125.90; 127.81; 129.18; 132.03; 136.04; 154.29. HR-
ESI-MS: 206.0923 ([M þ H]þ, C10H12N3Oþ2 ; calc. 206.0929). Anal. calc.
for C10H11N3O2 (205.21): C 58.53, H 5.40, N 20.48; found: C 58.29, H
5.43, N 20.27.
1-(1,2,3-Benzotriazin-3(4H)-yl)ethanone (2d). White solid. M.p.
1
119 – 1218 (hexane/CH2Cl2). IR (KBr): 1693. H-NMR: 2.59 (s, 3 H);
4.80 (s, 2 H); 7.09 (dd, J ¼ 6.3, 2.9, 1 H); 7.41 – 7.45 (m, 2 H); 7,70 (dd,
J ¼ 6.3, 2.9, 1 H). 13C-NMR: 21.58; 38.18; 118.63; 126.30; 127.98; 129.17;
132.11; 135.81; 173.71. HR-ESI-MS: 176.0816 ([M þ H]þ, C9H10N3Oþ;
calc. 176.0824). Anal. calc. for C9H9N3O (175.19): C 61.70, H 5.18, N
23.99; found: C 61.70, H 5.21, N 23.81.
1-(4-Phenyl-1,2,3-benzotriazin-3(4H)-yl)ethanone (2l). White sol-
id. M.p. 95 – 968 (hexane/CH2Cl2) ([3] 96 – 978). The spectral (IR and
1H-NMR) data for this product were identical to those reported in [3].
1,5-Bis(1,2,3-benzotriazin-3(4H)-yl)pentane-1,5-dione (3). Beige
solid. M.p. 147 – 1498 (hexane/CHCl3). IR (KBr): 1697. 1H-NMR:
2.24 (quint, J ¼ 7.4, 2 H); 3.13 (t, J ¼ 7.4, 4 H); 4.79 (s, 4 H); 7.09 (dd, J ¼
8.0, 1.7, 2 H); 7.41 – 7.43 (m, 4 H); 7.67 (dd, J ¼ 8.6, 2.3, 2 H). 13C-NMR:
19.61; 32.86; 38.27; 118.79; 126.31; 127.97; 129.14; 132.08; 135.95;
175.45. HR-ESI-MS: 385.1385 ([M þ Na]þ, C19H18N6NaO2þ ; calc.
385.1389). Anal. calc. for C19H18N6O2 (362.39): C 62.97, H 5.01, N
23.19; found: C 62.83, H 5.04, N 22.96.
3-Benzyl-3,4-dihydro-1,2,3-benzotriazine (4a). Yellow solid. M.p.
80 – 828 (hexane/CH2Cl2). IR (KBr): 1425, 1098. 1H-NMR: 4.22 (s,
2 H); 4.86 (s, 2 H); 6.82 (d, J ¼ 7.4, 1 H); 7.23 (td, J ¼ 7.4, 1.1, 2 H); 7.30 –
7.39 (m, 5 H); 7.46 (dd, J ¼ 8.0, 1.1, 1 H). 13C-NMR: 42.91; 60.41; 117.61;
125.35; 125.44; 128.12; 128.46; 128.78; 128.83; 129.50; 134.97; 126.91.
HR-EI-MS: 223.1106 (Mþ, C14H13Nþ3 ; calc. 223.1109). Anal. calc. for
C14H13N3 (223.27): C 75.31, H 5.87, N 18.82; found: C 75.02, H 5.84, N
18.67.
tert-Butyl 1,2,3-Benzotriazine-3(4H)-carboxylate (2e). Pale-yellow
1
solid. M.p. 83 – 848 (hexane/CH2Cl2). IR (KBr): 1714: H-NMR: 1.62
(s, 9 H); 4.71 (s, 2 H); 7.06 (dd, J ¼ 4.6, 4.0, 1 H); 7.40 (dd, J ¼ 7.4, 4.0,
1 H); 7.42 (dd, J ¼ 7.4, 3.4, 1 H); 7.67 (dd, J ¼ 5.1, 3.4, 1 H). 13C-NMR:
28.14; 39.68; 83.66; 119.38; 125.87; 127.49; 129.09; 131.74; 136.30;
152.85. HR-ESI-MS: 234.1237 ([M þ H]þ, C12H16N3O2þ ; calc.
234.1242). Anal. calc. for C12H15N3O2 (233.27): C 61.79, H 6.48, N
18.01; found: C 61.70, H 6.62, N 17.98.
(4-Methyl-1,2,3-benzotriazin-3(4H)-yl)(phenyl)methanone (2f).
Beige solid. M.p. 95 – 978 (hexane/CH2Cl2). IR (KBr): 1679, 1602.
1H-NMR: 1.40 (d, J ¼ 6.3, 3 H); 5.64 (q, J ¼ 6.3, 1 H); 7.17 (d, J ¼ 6.9,
1 H); 7.44 (t, J ¼ 7.4, 2 H); 7.47 – 7.53 (m, 3 H); 7.72 (d, J ¼ 7.4, 2 H); 7.76
(dd, J ¼ 7.4, 1.1, 1 H). 13C-NMR: 21.90; 45.15; 125.53 (2 overlapped Cs);
127.24; 127.85; 128.96; 130.29; 131.56; 132.38; 133.45; 136.43; 171.42.
HR-ESI-MS: 252.1132 ([M þ H]þ, C15H14N3Oþ; calc. 252.1137). Anal.
calc. for C15H13N3O (251.28): C 71.70, H 5.21, N 16.72; found: C 71.44, H
5.32, N 16.51.
3-Benzyl-3,4-dihydro-4-methyl-1,2,3-benzotriazine (4b). Represen-
tative Procedure. Compound 1b (0.48 g, 2.1 mmol) in THF (12 ml) at
À 788 was treated with BuLi (1.6m in hexane; 2.1 mmol) as described
for the preparation of 2a. After BnBr (0.36 g, 2.1 mmol) was added, the
temp. was gradually warmed to r.t. and stirring was continued overnight
at the same temp. The resulting mixture was worked up as described for
the preparation of 2a and the crude product was purified by CC (SiO2)
(4-Methyl-1,2,3-benzotriazin-3(4H)-yl)(2-methylphenyl)metha-
none (2g). Pale-yellow solid. M.p. 78 – 818 (hexane/CH2Cl2). IR (KBr):
1680. 1H-NMR: 1.43 (d, J ¼ 6.9, 3 H); 2.33 (s, 3 H); 5.74 (q, J ¼ 6.9,
1 H); 7.18 (dd, J ¼ 7.4, 1.1, 1 H); 7.23 (t, J ¼ 7.4, 1 H); 7.24 (d, J ¼ 7.4,
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