Tetrahedron
7
115-116 °C; IR (neat) 2350, 1507, 1419 cm-1; 1H-NMR (400 MHz,
CDCl3): δ = 3.97 (s, 3H), 6.58 (d, 2H, J = 2.0 Hz), 7.34 (t, 1H, J =
7.2 Hz), 7.44 (t, 2H, J = 7.2 Hz), 7.63 (d, 2H, J = 8.1 Hz), 7.63 (d,
2H, J = 8.0 Hz), 7.86 (d, 2H, J = 8.6 Hz); 13C-NMR (100 MHz,
CDCl3): δ =38.9, 102.8, 125.8, 126.8, 127.1, 127.2, 128.6, 131.3,
132.4, 140.1, 140.7, 151.1; HRMS (ESI) Calcd for C16H15N2
[M+H]+ = 235.1230, Found = 235.1228.
8.1 Hz), 7.34 (d, 1H, J = 2.0 Hz), 7.51 (d, 1H, J = 8.1 Hz), 7.66 (s,
1H); 13C-NMR (100 MHz, CDCl3): δ = 29.4, 38.7, 71.2, 102.0,
109.0, 122.1, 125.4, 126.2, 127.2, 131.1, 151.6, 159.6; HRMS
(ESI) Calcd for C12H13ON2 [M+H]+ = 201.1022, Found =
201.1021.
4.2.15
3-(2’-Methoxy-5’-methylphenyl)-1-methylpyrazole
(2K): Purified by column chromatography on silica gel (eluent,
hexane : ethyl acetate = 4:1); Yield: 112.8mg (56%); colorless oil;
IR (neat) 2938, 2360, 1611, 1284 cm-1; 1H-NMR (400 MHz,
CDCl3): δ = 2.32 (s, 3H), 3.86 (s, 3H), 3.96 (s, 3H), 6.75 (d, 1H, J
= 2.2 Hz), 6.86 (d, 1H, J = 7.6 Hz), 7.07 (d, 1H, J = 7.6 Hz), 7.37
(d, 1H, J = 2.2 Hz), 7.71(s, 1H); 13C-NMR (100 MHz, CDCl3): δ
= 20.3, 38.7, 55.3, 106.7, 111.1, 121.8, 128.8, 129.7 (2C), 130.2,
4.2.9 3-(2’,5’-dimethylphenyl)-1-methylpyrazole (2E): Purified
by column chromatography on silica gel (eluent, hexane : ethyl
acetate = 8:1); Yield: 165.3mg (89%); pale yellow oil; IR (neat)
1
2946, 1615, 1456 cm-1; H-NMR (400 MHz, CDCl3): δ = 2.33 (s,
3H), 2.41 (s, 3H), 3.96 (s, 3H), 6.38 (d, 1H, J = 2.0 Hz), 7.04 (d,
1H, J = 7.6 Hz), 7.12 (d, 1H, J = 7.8 Hz), 7.38 (d, 1H, J = 2.0 Hz),
7.39 (s, 3H); 13C-NMR (100 MHz, CDCl3): δ =20.5, 20.8, 38.9,
105.9, 128.2, 129.7, 130.2, 130.5, 132.6, 133.0, 135.1, 151.8;
HRMS (ESI) Calcd for C12H15N2 [M+H]+ = 187.1230, Found =
187.1225.
148.2, 154.2; HRMS (ESI) Calcd for C12H15ON2 [M+H]+
203.1179, Found = 203.1176.
=
4.2.16
3-(2’-Hydroxy-5’-methylphenyl)-1-methylpyrazole
(2K‘): Purified by column chromatography on silica gel (eluent,
hexane : ethyl acetate = 7:1); Yield: 96.9mg (52%); pale yellow
solid; Mp: 70-71 °C; IR (neat) 3648, 2943, 1518, 1284 cm-1;
1H-NMR (400 MHz, CDCl3): δ = 2.31 (s, 3H), 3.94 (s, 3H), 6.59
(d, 1H, J = 2.2 Hz), 6.91 (d, 1H, J = 8.1 Hz), 7.00 (dd, 1H , J =
8.1, 2.0 Hz), 7.35 (d, 1H, J = 2.0 Hz), 7.39 (d, 1H, J = 2.2 Hz),
10.61 (s, 1H); 13C-NMR (100 MHz, CDCl3): δ = 20.5, 38.7, 101.9,
116.2, 116.6, 126.3, 128.0, 129.5, 130.8, 151.2, 153.4: HRMS
(ESI) Calcd for C11H13ON2 [M+H]+ = 189.1022, Found =
189.1022.
4.2.10 1-Methyl-3-(3’,4’,5’-trimethylphenyl)pyrazole (2F):
Purified by column chromatography on silica gel (eluent, hexane :
ethyl acetate = 8:1); Yield: 144.8mg (72%); pale yellow solid;
1
Mp: 43-45 °C; IR (neat) 2938, 1499, 1456 cm-1; H-NMR (400
MHz, CDCl3): δ = 2.18 (s, 3H), 2.32 (s, 6H), 3.94 (s, 3H) , 6.49 (d,
1H, J = 2.2 Hz), 7.35 (d, 1H, J = 2.2 Hz), 7.43 (s, 2H); 13C-NMR
(100 MHz, CDCl3): δ = 15.1, 20.5, 38.8, 102.4, 124.5, 130.2,
131.1, 134.4, 136.5, 151.7; HRMS (ESI) Calcd for C13H17N2
[M+H]+ = 201.1386, Found = 201.1385.
4.2.11 3-Mesityl-1-methylpyrazole (2G): Purified by column
chromatography on silica gel (eluent, hexane : ethyl acetate =
8:1); Yield: 107.1mg (53%); pale yellow oil; IR (neat) 2922, 1499,
1456 cm-1; 1H-NMR (400 MHz, CDCl3): δ = 2.10 (s, 6H), 2.29 (s,
3H), 3.94 (s, 3H), 6.12 (d, 1H, J = 2.2 Hz), 6.89 (s, 2H), 7.40 (d,
1H, J = 2.2 Hz); 13C-NMR (100 MHz, CDCl3): δ = 20.4, 21.0,
38.7, 106.3, 127.9, 130.0, 131.0, 137.0, 137.4, 150.4; HRMS
(ESI) Calcd for C13H17N2 [M+H]+ = 201.1386, Found = 201.1385.
4.2.17 3-(4’-Fluorophenyl)-1-methylpyrazole (2L): Purified by
column chromatography on silica gel (eluent, hexane : ethyl
acetate = 6:1); Yield: 133.0mg (75%); pale yellow solid; Mp:
1
68-69 °C; IR (neat) 2971, 2360, 1507, 1065 cm-1; H-NMR (400
MHz, CDCl3): δ = 3.94 (s, 3H), 6.48 (d, 1H, J = 2.2 Hz), 7.08 (t,
2H, J = 8.8 Hz), 7.37 (d, 1H, J = 2.2 Hz), 7.72-7.78 (m, 2H);
13C-NMR (100 MHz, CDCl3): δ = 38.9, 102.5, 115.4 (d, JC-F
=
21.6 Hz), 127.0 (d, JC-F = 8.4 Hz), 129.7, 131.4, 150.6, 162.3 (d,
JC-F = 246.1 Hz); HRMS (ESI) Calcd for C10H10FN2 [M+H]+ =
177.0823, Found = 177.0822.
4.2.12 3-(4’-Methoxyphenyl)-1-methylpyrazole (2H): Purified
by column chromatography on silica gel (eluent, hexane : ethyl
acetate = 4:1); Yield: 155.3mg (82%); white solid; Mp: 73-74 °C;
4.2.18 3-(4’-Chlorophenyl)-1-methylpyrazole (2M): Purified by
column chromatography on silica gel (eluent, hexane : ethyl
acetate = 6:1); Yield: 127.9mg (66%); white solid; Mp: 68-69 °C;
IR (neat) 2970, 2361, 1455, 757 cm-1; 1H-NMR (400 MHz,
CDCl3): δ = 3.94 (s, 3H), 6.50 (d, 1H, J = 2.2 Hz), 7.35 (d, 2H, J
= 8.6 Hz), 7.37 (d, 1H, J = 2.2 Hz), 7.72 (d, 2H, J = 8.6 Hz);
13C-NMR (100 MHz, CDCl3): δ = 38.9, 102.7, 126.6, 128.6, 131.4,
132.0, 133.0, 150.3; HRMS (ESI) Calcd for C10H1035ClN2 [M+H]+
= 193.0527, Found = 193.0531.
1
IR (neat) 2966, 1615, 1507 cm-1; H-NMR (400 MHz, CDCl3): δ
= 3.83 (s, 3H), 3.93 (s, 3H), 6.46 (d, 1H, J = 2.0 Hz), 6.92 (d, 2H,
J = 8.7 Hz), 7.35 (d, 1H, J = 2.0 Hz), 7.71 (d, 2H, J = 8.7 Hz);
13C-NMR (100 MHz, CDCl3): δ =39.0, 55.3, 102.3, 114.0, 126.5,
126.8, 131.4, 151.4, 159.2; HRMS (ESI) Calcd for C11H13ON2
[M+H]+ = 189.1022, Found = 189.1022.
4.2.13 3-(4’-Ethoxyphenyl)-1-methylpyrazole (2I): Purified by
column chromatography on silica gel (eluent, hexane : ethyl
acetate = 4:1); Yield: 133.7mg (66%); white solid; Mp: 86-87 °C;
4.2.19 3-(4’-Bromophenyl)-1-methylpyrazole (2N): Purified by
column chromatography on silica gel (eluent, hexane : ethyl
acetate = 5:1); Yield: 129.9mg (55%); white solid; Mp: 76-77 °C;
IR (neat) 2341, 1498, 1456, 614 cm-1; 1H-NMR (400 MHz,
CDCl3): δ = 3.94 (s, 3H), 6.51 (d, 1H, J = 2.0 Hz), 7.37 (d, 1H, J
= 2.0 Hz), 7.50 (d, 2H, J = 8.1 Hz), 7.66 (d, 2H, J = 8.1 Hz);
13C-NMR (100 MHz, CDCl3): δ = 39.0, 102.7, 121.2, 126.9, 131.4,
131.6, 132.4, 150.3; HRMS (ESI) Calcd for C10H1079BrN2
[M+H]+ = 237.0022, Found = 237.0022.
1
IR (neat) 2360, 1507, 1240 cm-1; H-NMR (400 MHz, CDCl3): δ
= 1.42 (t, 3H, J = 6.9 Hz ), 3.93 (s, 3H), 4.06 (q, 2H, J = 6.9 Hz),
6.45 (d, 1H, J = 2.2 Hz), 6.91 (d, 2H, J = 8.7 Hz), 7.35 (d, 1H, J =
2.2 Hz), 7.70 (d, 2H, J = 8.7 Hz); 13C-NMR (100 MHz, CDCl3): δ
= 14.7, 38.8, 63.3, 102.1, 114.4, 126.1, 126.6, 131.2, 151.4, 158.4;
HRMS (ESI) Calcd for C12H15ON2 [M+H]+ = 203.1179 Found =
203.1177.
4.2.14
3-(2’,3’-Dihydrobenzofuran-5’-yl)-1-methylpyrazole
(2J): Purified by column chromatography on silica gel (eluent,
4.2.20 1-Methyl-3-(naphthalen-2’-yl)pyrazole (2O): Purified by
column chromatography on silica gel (eluent, hexane : ethyl
acetate = 7:1); Yield: 175.4mg (84%); pale yellow oil; IR (neat)
hexane : ethyl acetate = 4:1); Yield: 149.8mg (75%); white solid;
1
Mp: 74-75 °C; IR (neat) 2960, 2360, 1457, 1227 cm-1; H-NMR
1
(400 MHz, CDCl3): δ = 3.32 (t, 2H, J = 8.6 Hz ), 3.93 (s, 3H),
4.59 (t, 2H, J = 8.6 Hz), 6.43 (d, 1H, J = 2.0 Hz), 6.79 (d, 1H, J =
3046, 2360, 1592, 1508 cm-1; H-NMR (400 MHz, CDCl3): δ =
4.04 (s, 3H), 6.55 (d, 1H, J = 2.0 Hz), 7.47-7.52 (m, 4H), 7.67 (d,