R. Romagnoli et al. / Bioorg. Med. Chem. 18 (2010) 5114–5122
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1H NMR (CDCl3) d: 3.40 (s, 3H), 3.46 (s, 3H), 3.94 (s, 3H), 6.70 (d,
J = 8.0 Hz, 1H), 6.89 (d, J = 8.0 Hz, 1H), 7.56 (t, J = 8.2 Hz, 1H), 10.3
(s, 1H).
conditions described for each compound. The progress of the reac-
tion was followed by thin-layer chromatography. The reaction
mixture was then cooled and purified by flash column chromatog-
raphy on silica gel.
5.2.5. O-2-Acetylphenyl N,N-dimethylcarbamothioate (6f)
The residue was chromatographed with EtOAc–petroleum ether
1:9 as eluent to give 6f as a white solid, yield: 95%, mp 77–79 °C. 1H
NMR (CDCl3) d: 2.66 (s, 3H), 3.36 (s, 3H), 3.45 (s, 3H), 7.07 (d,
J = 8.2 Hz, 1H), 7.32 (t, J = 7.2 Hz, 1H), 7.57 (t, J = 7.2 Hz, 1H), 7.80
(d, J = 8.2 Hz, 1H).
5.3.1. S-2-Formyl-3-methoxyphenyl N,N-dimethylcarb-
amothioate (7b)
MW irradiation conditions: power (P): 200 W, temperature (T):
210 °C, ramp time (RT): 2 min; time: 2 min. The residue was chro-
matographed with EtOAc–petroleum ether 3:7 as eluent to give 7b
as a yellow oil, yield: 60 %. 1H NMR (CDCl3) d: 3.01 (s, 3H), 3.13 (s,
3H), 3.90 (s, 3H), 7.02 (d, J = 8.4 Hz, 1H), 7.21 (d, J = 8.4 Hz, 1H),
7.47 (t, J = 8.4 Hz, 1H), 10.5 (s, 1H).
5.2.6. O-2-Acetyl-3-methoxyphenyl N,N-dimethylcarb-
amothioate (6g)
The residue was chromatographed with EtOAc–petroleum ether
2:8 as eluent to give 6g as a white solid, yield: 79%, mp 89–92 °C.
1H NMR (CDCl3) d: 2.53 (s, 3H), 3.29 (s, 3H), 3.39 (s, 3H), 3.86 (s,
3H), 6.68 (d, J = 8.4 Hz, 1H), 6.81 (d, J = 8.4 Hz, 1H), 7.35 (d,
J = 8.4 Hz, 1H).
5.3.2. S-2-Formyl-4-methoxyphenyl N,N-dimethylcarb-
amothioate (7c)
MW conditions: P: 280 W, T: 240 °C, RT: 2 min; time: 1 min. The
residue was chromatographed with EtOAc–petroleum ether 2:8 as
eluent to give 7c as a yellow oil, yield: 48%. 1H NMR (CDCl3) d: 3.03
(s, 3H), 3.16 (s, 3H), 3.87 (s, 3H), 7.12 (d, J = 8.2 Hz, 1H), 7.46 (d,
J = 8.2 Hz, 1H), 7.52 (s, 1H), 10.3 (s, 1H).
5.2.7. O-2-Acetyl-4-methoxyphenyl N,N-dimethylcarb-
amothioate (6h)
The residue was chromatographed with EtOAc–petroleum ether
2:8 as eluent to give 6h as a white solid, yield: 94%, mp 83–85 °C.
1H NMR (CDCl3) d: 2.52 (s, 3H), 3.38 (s, 3H), 3.45 (s, 3H), 3.84 (s,
3H), 7.01 (s, 1H), 7.04 (m, 1H), 7.29 (m, 1H).
5.3.3. S-2-Formyl-5-methoxyphenyl N,N-dimethylcarb-
amothioate (7d)
MW conditions: P: 280 W, T: 170 °C, RT: 2 min; time: 10 min.
The residue was chromatographed with EtOAc–petroleum ether
3:7 as eluent to give 7d as a white solid, yield: 92%, mp 81–
83 °C. 1H NMR (CDCl3) d: 3.02 (s, 3H), 3.17 (s, 3H), 3.87 (s, 3H),
7.07 (d, J = 8.4 Hz, 1H), 7.08 (s, 1H), 8.01 (d, J = 8.4 Hz, 1H), 10.25
(s, 1H).
5.2.8. O-2-Acetyl-5-methoxyphenyl N,N-dimethylcarb-
amothioate (6i)
The residue was chromatographed with EtOAc–petroleum ether
2:8 as eluent to give 6i as colourless oil, yield: 95%. 1H NMR (CDCl3)
d: 1.42 (t, J = 7.0 Hz, 3H), 2.49 (s, 3H), 3.39 (s, 3H), 3.46 (s, 3H), 4.04
(q, J = 7.0 Hz, 2H), 6.56 (d, J = 2.6 Hz, 1H), 6.84 (dd, J = 2.6 and
8.8 Hz, 1H), 7.80 (d, J = 8.8 Hz, 1H).
5.3.4. S-2-Formyl-6-methoxyphenyl N,N-dimethylcarb-
amothioate (7e)
5.2.9. O-2-Acetyl-6-methoxyphenyl N,N-dimethylcarb-
amothioate (6j)
MW conditions: P: 200 W, T: 210 °C, RT: 2 min; time: 2 min. The
residue was chromatographed with EtOAc–petroleum ether 3:7 as
eluent to give 7e as a yellow oil, yield: 67 %. 1H NMR (CDCl3) d: 3.01
(s, 3H), 3.21 (s, 3H), 4.31 (s, 3H), 7.18 (d, J = 8.0 Hz, 1H), 7.52 (t,
J = 8.4 Hz, 1H), 7.62 (d, J = 8.4 Hz, 1H), 10.4 (s, 1H).
The residue was chromatographed with EtOAc–petroleum ether
2:8 as eluent to give 6j as a white solid, yield: 78%, mp 144–146 °C.
1H NMR (CDCl3) d: 2.55 (s, 3H), 3.40 (s, 3H), 3.46 (s, 3H), 3.84 (s,
3H), 7.12 (d, J = 8.0 Hz, 1H), 7.27 (t, J = 8.4 Hz, 1H), 7.36 (d,
J = 8.4 Hz, 1H).
5.3.5. S-2-Acetylphenyl N,N-dimethylcarbamothioate (7f)
MW conditions: P: 200 W, T: 210 °C, RT: 2 min; time: 3 min. The
residue was chromatographed with EtOAc–petroleum ether 2:8 as
eluent to give 7f as a brown oil, yield: 61%. 1H NMR (CDCl3) d: 2.57
(s, 3H), 3.04 (s, 3H), 3.07 (s, 3H), 7.45 (m, 2H), 7.59 (m, 2H).
5.2.10. O-2-Formyl-4,5-dimethoxyphenyl N,N-dimethylcarb-
amothioate (6k)
The residue was chromatographed with EtOAc–petroleum ether
3:7 as eluent to give 6k as a white solid, yield: 69%, mp 172–
174 °C. 1H NMR (CDCl3) d: 3.42 (s, 3H), 3.48 (s, 3H), 3.94 (s, 6H),
6.61 (s, 1H), 7.36 (s, 1H), 9.94 (s, 1H).
5.3.6. S-2-Acetyl-3-methoxyphenyl N,N-dimethylcarb-
amothioate (7g)
MW conditions: P: 200 W, T: 210 °C, RT: 2 min; time: 5 min. The
residue was chromatographed with EtOAc–petroleum ether 4:6 as
eluent to give 7g as a brown oil, yield: 82%. 1H NMR (CDCl3) d: 2.46
(s, 3H), 2.99 (s, 3H), 3.02 (s, 3H), 3.79 (s, 3H), 6.92 (d, J = 8.4 Hz, 1H),
7.11 (d, J = 8.4 Hz, 1H), 7.27 (t, J = 8.4 Hz, 1H).
5.2.11. O-2-Acetyl-5-ethoxyphenyl N,N-dimethylcarb-
amothioate (6l)
The residue was chromatographed with EtOAc–petroleum ether
2:8 as eluent to give 6l as a white solid, yield: 81%, mp 84–86 °C. 1H
NMR (CDCl3) d: 2.48 (s, 3H), 3.38 (s, 3H), 3.45 (s, 3H), 3.84 (s, 3H),
6.58 (d, J = 2.8 Hz, 1H), 6.84 (dd, J = 2.4 and 8.8 Hz, 1H), 7.80 (d,
J = 8.8 Hz, 1H).
5.3.7. S-2-Acetyl-4-methoxyphenyl N,N-dimethylcarb-
amothioate (7h)
MW conditions: P: 280 W, T: 240 °C, RT: 2 min; time: 1 min. The
residue was chromatographed with EtOAc–petroleum ether 4:6 as
eluent to give 7h as a brown oil, yield: 53%. 1H NMR (CDCl3) d: 2.56
(s, 3H), 3.04 (s, 3H), 3.10 (s, 3H), 3.83 (s, 3H), 6.95 (d, J = 8.6 Hz, 1H),
6.99 (s, 1H), 7.44 (d, J = 8.6 Hz, 1H).
5.2.12. O-2-Acetyl-5-fluorophenyl N,N-dimethylcarbamothioate
(6m)
The residue was chromatographed with EtOAc–petroleum ether
3:7 as eluent to give 6m as a colourless oil, yield: 90%. 1H NMR
(CDCl3) d: 2.52 (s, 3H), 3.39 (s, 3H), 3.45 (s, 3H), 6.85 (dd, J = 2.8
and 7.0 Hz, 1H), 7.03 (m, 1H), 7.82 (dd, J = 6.4 and 8.8 Hz, 1H).
5.3.8. S-2-Acetyl-5-methoxyphenyl N,N-dimethylcarb-
amothioate (7i)
5.3. General procedure (B) for the synthesis of compounds 7b-m
MW conditions: P: 200 W, T: 210 °C, RT: 2 min; time: 4 min.
The residue was chromatographed with EtOAc–petroleum ether
4:6 as eluent to give 7i as a brown oil, yield: 51%. 1H NMR
The N,N-dimethylcarbamothioate 6b–m (0.5 mmol) was placed
in a 10 mL closed vial and irradiated in a focused MW oven at the