2
687
Synthesis
F. Lassagne et al.
Paper
8
-Methyl-2-phenylquinoxaline (5e)
Prepared from 3-methylbenzene-1,2-diamine (1c) and phenylglyoxal
2e) according to General Procedure B as a pale-yellow powder; yield:
Crystal data: C19H14N , Mr = 270.32, monoclinic, P2 /n, a =
2 1
1
4.4579(13), b = 4.6502(4), c = 20.8516(17) Å, β = 103.783(3)°, V =
3
–3
–1
1361.5(2) Å , Z = 4, ρ = 1.319 g cm , μ = 0.078 mm {A final refine-
(
c
2
ment on F with 3105 unique intensities and 191 parameters con-
verged at wR(F ) = 0.1334 [R(F) = 0.0542] for 1796 observed reflec-
0.21 g (94%); mp 104 °C; R = 0.21 (pentane–EtOAc, 4:1).
f
2
1
H NMR (300 MHz, CDCl ): δ = 2.88 (s, 3 H), 7.50–7.65 (m, 5 H), 7.93–
3
44
tions with I > 2σ(I).}
7.97 (m, 1 H), 8.23–8.28 (m, 2 H), 9.33 (s, 1 H).
13
C NMR (75 MHz, CDCl ): δ = 17.2, 127.0, 127.5 (2 C), 129.2 (2 C),
3
5
-Methyl-2-(2-naphthyl)quinoxaline (5′g)
This was similarly isolated as a pale-yellow powder; yield: 13 mg
5%); mp 154 °C; R = 0.51 (CH Cl –pentane, 95:5).
1
29.4, 130.1, 130.3, 137.1, 138.1, 141.4, 141.7, 142.6, 150.3.
The spectral data are similar to those previously reported.43
(
f
2
2
Crystal data: C15H12N , M = 220.26, monoclinic, C2/c, a = 25.6227(11),
2
r
The compound was unambiguously identified by X-ray diffraction.
3
b = 3.8431(2), c = 22.7091(13) Å, β = 92.300(2)°, V = 2234.4(2) Å , Z =
–
3
–1
2
Crystal data: 270.32, monoclinic, P2 /c, a =
C
19
H
14
N
2
,
M
r
=
1
8
, ρ = 1.31 g cm , μ = 0.078 mm {A final refinement on F with 2519
c
2
12.7711(10), b = 4.4124(3), c = 23.9462(16) Å, β = 95.816(3)°, V =
unique intensities and 155 parameters converged at wR(F ) = 0.1044
3
–3
–1
R(F) = 0.0431] for 1989 observed reflections with I > 2σ(I).}4
4
1342.45(17) Å , Z = 4, ρ
c
= 1.337 g cm , μ = 0.079 mm {A final refine-
[
2
ment on F with 3068 unique intensities and 191 parameters con-
2
verged at wR(F ) = 0.112 [R(F) = 0.0418] for 2388 observed reflections
2
-(4-Methoxyphenyl)-8-methylquinoxaline (5f)
44
with I > 2σ(I).}
Prepared from 3-methylbenzene-1,2-diamine (1c) and 4-(methoxy-
phenyl)glyoxal (2f) according to General Procedure B as a pale-yellow
powder; yield: 0.24 g (95%); mp 96 °C; R = 0.50 (CH Cl –pentane,
2
-(2-Furyl)-8-methylquinoxaline (5h)
f
2
2
Prepared from 3-methylbenzene-1,2-diamine (1c) and (2-furyl)gly-
oxal (2h) according to General Procedure B as a beige powder; yield:
0.20 g (95%); R = 0.21 (CH Cl –pentane, 9:1); mp 70–72 °C.
4:1).
1
H NMR (300 MHz, CDCl ): δ = 2.84 (s, 3 H), 3.87 (s, 3 H), 7.04 (d, J =
3
f
2
2
9.0 MHz, 2 H), 7.56 (d, J = 5.9 MHz, 2 H), 7.91 (dd, J = 5.9, 4.0 MHz, 1
1
H NMR (300 MHz, CDCl ): δ = 2.81 (s, 3 H), 6.62 (dd, J = 3.5, 1.8 MHz,
3
H), 8.19 (d, J = 9.0 MHz, 2 H), 9.26 (s, 1 H).
1
H), 7.33 (dd, J = 3.5, 0.8 MHz, 1 H), 7.56–7.59 (m, 2 H), 7.66 (dd, J =
13
C NMR (75 MHz, CDCl ): δ = 17.2, 55.5, 114.5 (2 C), 126.9, 128.8,
3
1.8, 0.8 MHz, 1 H), 7.89 (dd, J = 5.4, 4.5 MHz, 1 H), 9.25 (s, 1 H).
128.9 (2 C), 129.7, 130.1, 137.7, 141.3, 141.3, 142.3, 149.8, 161.4.
13
C NMR (75 MHz, CDCl ): δ = 17.0, 111.2, 112.4, 127.0, 128.9, 130.2,
3
Crystal data: C16H14N O, Mr
=
250.29, monoclinic, C2/c,
a =
2
137.4, 141.1, 141.3, 141.3, 142.6, 144.6, 152.2.
Crystal data: 2(C13 O), M = 420.46, monoclinic, P2
17.698(3), b = 4.7568(7), c = 24.587(4) Å, β = 92.295(6)°, V = 2068.2(6)
2
2
4.4240(16), b = 3.9155(2), c = 27.2910(15) Å, β = 107.981(3)°, V =
3
–3
–1
H
10
N
2
r
/c, a =
1
482.4(2) Å , Z = 8, ρ = 1.339 g cm , μ = 0.085 mm {A final refine-
c
2
ment on F with 2808 unique intensities and 174 parameters con-
verged at wR(F ) = 0.1155 [R(F) = 0.0459] for 2176 observed reflec-
tions with I > 2σ(I).}
3
= 1.35 g cm , μ = 0.088 mm {A final refinement on F2
–3
–1
2
Å , Z = 4, ρ
c
44
with 4713 unique intensities and 292 parameters converged at
wR(F ) = 0.1677 [R(F) = 0.0778] for 1926 observed reflections with I >
2
44
2
σ(I).}
8-Methyl-2-(2-nitrophenyl)quinoxaline (5j)
Prepared from 3-methylbenzene-1,2-diamine (1c) and (2-nitrophe-
nyl)glyoxal (2j) according to General Procedure B as a white powder;
yield: 0.25 g (91%); mp 128 °C.
8
-Methyl-2-(2-thienyl)quinoxaline (5i)
Prepared from 3-methylbenzene-1,2-diamine (1b) and (2-thie-
nyl)glyoxal (2i) according to General Procedure B as a pale-yellow
powder; yield: 0.22 g (95%); mp 120 °C; R = 0.26 (CH Cl –pentane,
1
H NMR (300 MHz, CDCl ): δ = 2.75 (s, 3 H), 7.62–7.84 (m, 5 H), 7.97–
3
f
2
2
8.02 (m, 2 H), 9.04 (s, 1 H).
9:1).
13
C NMR (75 MHz, CDCl ): δ = 17.1, 124.9, 127.0, 130.2, 130.4, 130.6,
1
3
H NMR (300 MHz, CDCl ): δ = 2.81 (s, 3 H), 7.18 (dd, J = 5.0, 3.7 MHz,
3
131.5, 132.7, 132.8, 138.3, 141.0, 141.8, 143.4, 148.9, 149.6.
1
H), 7.51 (dd, J = 5.0, 1.1 MHz, 1 H), 7.52–7.58 (m, 2 H), 7.83 (dd, J =
Crystal data: C15H11N O , Mr
=
265.27, monoclinic, P2 /n,
a
=
3.7, 1.1 MHz, 1 H), 7.86–7.90 (m, 1 H), 9.19 (s, 1 H).
3
2
1
7
.7038(3), b = 13.4722(6), c = 12.1711(6) Å, β = 96.793(2)°, V =
13
C NMR (75 MHz, CDCl ): δ = 17.0, 126.6, 127.0, 128.5, 129.0, 129.7,
3
3
–3
–1
1254.34(10) Å , Z = 4, ρ = 1.405 g cm , μ = 0.097 mm {A final refine-
c
130.5, 137.6, 141.2, 141.4, 141.5, 143.0, 146.2.
2
ment on F with 2861 unique intensities and 182 parameters con-
verged at wR(F ) = 0.1018 [R(F) = 0.0385] for 2416 observed reflec-
tions with I > 2σ(I).}
2
Crystal data: C13
H
10
N
2
S, M
r
= 226.29, monoclinic, P2
1
/c, a = 12.868(2),
3
44
b = 4.5228(8), c = 18.899(3) Å, β = 92.293(6)°, V = 1099.0(3) Å , Z = 4,
ρc = 1.368 g cm , μ = 0.265 mm {A final refinement on F with 2496
unique intensities and 146 parameters converged at wR(F ) = 0.1249
–3
–1
2
2
8
-Methyl-2-(2-naphthyl)quinoxaline (5g)
44
[
R(F) = 0.0535] for 1579 observed reflections with I > 2σ(I).}
Prepared from 3-methylbenzene-1,2-diamine (1c) and (2-naphth-
yl)glyoxal (2g) according to General Procedure B as a pale-yellow
powder; yield: 0.25 g (94%); mp 148–150 °C; R = 0.37 (CH Cl –pen-
5
-Methyl-2-(2-thienyl)quinoxaline (5′i)
This was similarly prepare as a pale-yellow powder; yield: 11 mg
5%); mp 178–180 °C; R = 0.40 (CH Cl –pentane, 9:1).
f
2
2
tane, 95:5).
(
f
2
2
1
H NMR (300 MHz, CDCl ): δ = 2.93 (s, 3 H), 7.55–7.59 (m, 2 H), 7.63–
3
The compound was unambiguously identified by X-ray diffraction.
Crystal data: S, 226.29, monoclinic, P2 /c,
12.4419(6), b = 4.7272(2), c = 18.1617(9) Å, β = 98.448(2)°, V =
7.66 (m, 2 H), 7.90–8.05 (m, 4 H), 8.46 (dd, J = 8.4, 1.8 MHz, 1 H), 8.69
(d, J = 1.2 MHz, 1 H), 9.50 (s, 1 H).
C
13
H
10
N
2
M
r
=
1
a =
13
C NMR (75 MHz, CDCl ): δ = 17.3, 124.6, 126.6, 126.9, 127.2, 127.2,
3
3
–3
–1
1056.60(9) Å , Z = 4, ρ = 1.423 g cm , μ = 0.275 mm {A final refine-
c
1
1
27.8, 128.9, 129.0, 129.4, 130.3, 133.4, 134.1, 134.4, 138.0, 141.4,
41.6, 142.7, 150.0.
©
Georg Thieme Verlag Stuttgart · New York — Synthesis 2015, 47, 2680–2689