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mmol), dry magnesium sulfate (0.5 g) and TMA (271 mg, 1.48
1.3. Synthesis of 3-acyl-2-arylamino-1,4-naphthoquinones
6a–d. General procedure21
mmol). Compound 5c (164 mg, 0.38 mmol, 51%), yellow solid,
mp: 256–258 ꢁC. IR (KBr) nmax cmꢀ1: 3400 (O–H), 3325 (N–H),
´
Suspension of acylhydroquinones 1a, 1b, 1d (1 equiv.), Ag2O
(2.6 equiv.), anhydrous MgSO4 (500 mg), and dichloromethane
(15 mL) were le with stirring at rt aer completion of the
reaction as indicated by TLC. The mixtures were ltered, the
solvent removed under reduced pressure and the residues dis-
solved in methanol. The required anilines (1.1 equiv.) were
added with stirring, and the resulting solutions were le at
room temperature aer completion of the reaction as indicated
by TLC. The solvent was evaporated under reduced pressure and
the residues were column chromatographied over silica gel
(8 : 2 petroleum ether/EtOAc) to yield the corresponding acyla-
minoquinones 6a–d.
3-Acetyl-2-anilino-1,4-naphthoquinone (6a). Prepared in
78% yield (2 h) from 1a (150 mg, 0.74 mmol), Ag2O (445 mg, 1.92
mmol), and aniline (75 mg, 0.81 mmol); dark red solid, mp:
135.5–136 ꢁC. 1H NMR (400 MHz, CDCl3): d 12.69 (bs, 1H, NH),
8.10 (d, 1H, J ¼ 7.4 Hz, 5-H), 7.82 (d, 1H, J ¼ 7.5 Hz, 8-H), 7.71 (t,
1H, J ¼ 7.4 Hz, 7-H), 7.56 (t, 1H, J ¼ 7.4 Hz, 6-H), 7.31 (t, 2H, J ¼
7.3 Hz, 30- and 50-H), 7.23 (t, 1H, J ¼ 7.1 Hz, 40-H), 7.04 (d, 2H, J ¼
7.5 Hz, 20-and 60-H), 2.63 (s, 3H, COCH3). 13C NMR (100 MHz,
CDCl3): d 202.9, 182.3, 181.7, 151.6, 139.4, 135.5, 133.6, 132.8,
131.4, 129.4 (2 ꢂ C), 127.1, 126.8, 126.3, 124.7 (2 ꢂ C), 112.3,
33.3. The spectral data are in agreement to those reported in
literature.21
2960 (C–H Ar), 1678 (C]O), 1257 (C–O–C); 1H NMR (400 MHz,
CDCl3) d: 9.69 (s, 1H, OH), 8.62 (bs, 1H, NH), 8.51 (d, 1H, J ¼
8.5 Hz, 1-H), 8.02 (d, 1H, J ¼ 8.0 Hz, 4-H), 7.70 (dd, 1H, J ¼ 8.0,
7.2 Hz, 3-H), 7.55 (dd, 1H, J ¼ 8.5, 7.3 Hz, 2-H), 7.51 (d, 1H, J ¼
4.8 Hz, 40-H), 7.12 (d, 1H, J ¼ 4.0 Hz, 20-H), 6.78 (dd, 1H, J ¼
4.8, 4.0 Hz, 30-H), 6.77 (s, 1H, 10-H), 3.93 (s, 3H, OMe), 3.71 (s,
3H, OMe), 3.61 (s, 3H, OMe); 13C NMR (100 MHz, CDCl3):
d 189.7, 153.3, 150.3, 147.1, 146.8, 136.0, 135.5, 133.3, 132.9,
128.7, 128.6, 127.4, 125.4, 125.0, 123.6, 123.3, 119.9, 113.5,
111.5, 111.4, 89.0, 61.2, 59.9, 56.1. HRMS (APCI): [M + H]+
calcd for C24H19NO5S: 434.10622; found 434.10483.
Compound 4f (150 mg, 0.33 mmol, 45%), red solid, mp: 172–
173 ꢁC. IR (KBr) nmax cmꢀ1: 3437 (O–H), 3294 (N–H), 2937 (C–H
´
1
Ar), 1639 (C]O), 1130 (C–O–C); H NMR (400 MHz, CDCl3):
d 8.15 (dd, 2H, J ¼ 7.7, 7.7 Hz, 5-H + 8-H), 7.81 (m, 2H, 7-H + 30-
H), 7.71 (t, 1H, J ¼ 7.5 Hz, 6-H), 7.46 (bs, 1H, NH), 6.90 (m, 1H,
20-H or 40-H), 6.44 (m, 1H, 40-H or 20-H) 6.19 (s, 2H, 200-H + 600-
H), 3.77 (s, 3H, OMe), 3.65 (s, 6H, OMe); 13C NMR (100 MHz,
CDCl3): d 182.2, 181.4, 180.9, 153.5, 153.2 (2 ꢂ C), 145.7,
143.5, 136.9, 135.6, 132.9, 132.7, 132.5, 129.7, 126.7, 126.6,
117.3, 112.8, 112.6, 102.8 (2 ꢂ C), 60.9, 55.9 (2 ꢂ C). HRMS
(APCI): [M + H]+ calcd for C24H19NO6S: 450.10114; found
450.09986.
(5-Hydroxy-7,8,9-trimethoxy-11H-benzo[a]carbazol-6-yl)-
(thiophen-3-yl)methanone (5d) and 2-(thiophene-3-carbonyl)-3-
2-Anilino-3-butiroyl-1,4-naphthoquinone (6b). Prepared in
71% yield (2.5 h) from 1b (100 mg, 0.43 mmol), Ag2O (260 mg,
1.12 mmol), and aniline (44 mg, 0.47 mmol); red solid, mp: 142–
142.5 ꢁC; 1H NMR (300 MHz, CDCl3): d 12.18 (bs, 1H, NH), 8.18
(dd, 1H, J ¼ 7.8, 0.8 Hz, 5-H), 7.94 (dd, 1H, J ¼ 7.7, 0.9 Hz, 8-H),
7.80 (dt, 1H, J ¼ 7.6, 1.4 Hz, 7-H), 7.65 (dt, 1H, J ¼ 7.5, 1.3 Hz, 6-
H), 7.39 (m, 2H, 30- and 50-H), 7.29 (m, 1H, 40-H), 7.12 (d, 2H, J ¼
7.6 Hz, 20- and 50-H), 3.05 (d, 2H, J ¼ 7.4 Hz, CO–CH2), 1.60 (m,
((3,4,5-trimethoxyphenyl)amino)naphthalene-1,4-dione
(4g).
These compounds were generated following the general
procedure from 1g (200 mg, 0.74 mmol), Ag2O (446 mg, 1.92
mmol), dry magnesium sulfate (0.5 g) and TMA (271 mg, 1.48
mmol). Compound 5d (186 mg, 0.43 mmol, 58%), dark yellow
solid, mp: 150–152 C. IR (KBr) nmax cmꢀ1: 3346 (O–H), 3107
ꢁ
´
(N–H), 2933 (C–H Ar), 1623 (C]O), 1126 (C–O–C); 1H NMR
2H, COCH2CH2), 0.96 (t, 3H, J ¼ 7.4 Hz, 13-COCH2CH2CH3). 13
C
(400 MHz, CDCl3): d 10.05 (s, 1H, OH), 8.69 (bs, 1H, NH), 8.52
(d, 1H, J ¼ 8.5 Hz, 1-H), 8.02 (d, 1H, J ¼ 8.0 Hz, 4-H), 7.69 (dd,
1H, J ¼ 8.0, 7.5 Hz, 3-H), 7.58 (d, 1H, J ¼ 5.2 Hz, 40-H), 7.55 (dd,
1H, J ¼ 8.0, 7.5 Hz, 2-H), 7.46 (m, 1H, 10-H), 7.14 (dd, 1H, J ¼
5.2, 3.0 Hz, 30-H), 6.75 (s, 1H, 10-H), 3.91 (s, 3H, OMe), 3.66 (s,
3H, OMe), 3.60 (s, 3H, OMe); 13C NMR (100 MHz, CDCl3) d:
191.4, 153.3, 150.8, 147.0, 144.0, 135.8, 135.5, 132.8, 128.7,
128.5, 127.7, 125.5, 124.9, 124.8, 123.7, 123.3, 119.9, 113.7,
111.7, 111.5, 89.0, 61.2, 59.9, 56.1. HRMS (APCI): [M + H]+ calcd
for C24H19NO5S: 434.10622; found 434.10451. Compound 4g
(90 mg, 0.20 mmol, 27%), red solid, mp: 102–103.5 ꢁC. IR (KBr)
NMR (75 MHz, CDCl3): d 205.1, 182.3, 181.6, 150.5, 139.1, 135.3,
133.4, 132.6, 131.0, 129.2 (2 ꢂ C), 126.9, 126.7, 126.1, 124.6 (2 ꢂ
C), 112.6, 46.7, 17.7, 13.9. The spectral data are in agreement to
those reported in literature.33
2-Anilino-3-benzoyl-1,4-naphthoquinone (6c). Prepared in
81% yield (3 h) from 1d (200 mg, 0.76 mmol), Ag2O (459 mg,
1.98 mmol), and aniline (78 mg, 0.84 mmol), red solid mp:
1
ꢁ
220.5–222.5 C. H NMR (300 MHz, CDCl3): d 8.18 (dd, 1H, J ¼
7.6, 1.2 Hz, 5-H), 8.12 (dd, 1H, J ¼ 7.8, 1.1 Hz, 8-H), 7.90 (bs, 1H,
NH), 7.81 (dt, 1H, J ¼ 7.5, 1.4 Hz, 7-H), 7.72 (dt, 1H, J ¼ 7.5,
1.4 Hz, 6-H), 7.55 (d, 2H, J ¼ 8.4 Hz, 30- and 50-H anilino), 7.46 (t,
1H, J ¼ 7.4 Hz, 40-H anilino), 7.29 (m, 3H, 20- 50-H anilino), 6.99
(m, 3H, benzoyl), 6.85 (m, 2H, benzoyl). 13C NMR (75 MHz,
CDCl3): d 193.7, 182.3, 182.1, 143.6, 137.4, 136.7, 135.5, 133.0,
132.9, 132.7, 129.9, 128.8 (4 ꢂ C), 128.2 (2 ꢂ C), 127.1, 126.7,
126.6, 126.1 (2 ꢂ C), 113.5. The spectral data are in agreement to
those reported in literature.33
nmax cmꢀ1: 3099 (N–H), 2939 (C–H Ar), 1662 (C]O), 1128 (C–
´
O–C); 1H NMR (400 MHz, CDCl3) d: 8.15 (dd, 2H, J ¼ 6.5,
6.5 Hz, 5-H + 8-H), 7.81 (m, 2H, 7-H + NH), 7.72 (t, 1H, J ¼
7.5 Hz, 6-H), 7.55 (d, 1H, J ¼ 4.7 Hz, 20-H or 30-H), 7.42 (d, 1H, J
¼ 4.7 Hz, 30-H or 20-H), 6.99 (dd, 1H, J ¼ 4.3, 4.0 Hz, 40-H), 6.12
(s, 2H, 200-H + 600-H), 3.79 (s, 3H, OMe), 3.60 (s, 6H, OMe); 13C
NMR (100 MHz, CDCl3): d 185.1, 182.2, 181.5, 153.1 (2 ꢂ C),
145.5, 143.1, 136.8, 135.6, 134.5, 133.4, 132.9, 132.8, 132.2,
129.7, 127.6, 126.8, 126.6, 113.3, 103.7 (2 ꢂ C), 60.9, 55.9 (2 ꢂ
C). HRMS (APCI): [M + H]+ calcd for C24H19NO6S: 450.10114;
found 450.09948.
2-(4-Nitroanilino)-3-benzoyl-1,4-naphthoquinone
(6d).
Prepared in 80% yield (48 h) from 1d (100 mg, 0.38 mmol), Ag2O
(229 mg, 0.99 mmol), p-nitroaniline (58 mg, 0.42 mmol); yellow
solid, mp: 261–261.5 ꢁC. IR (KBr) nmax cmꢀ1: 3321 (N–H),
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RSC Adv., 2017, 7, 24813–24821 | 24819