7-Hydroxy-4-(3,4,5-trimethoxyphenyl)chromen-2-one (3ae). Off-white crystals, mp 259-260ºC
1
(recrystallized from EtOH) (lit. [31] 253ºC), Rf 0.26 (dichloromethane–methanol, 20:1). H NMR, δ, ppm (J,
Hz): 10.62 (1H, br s); 7.43 (1H, d, J = 9.4); 6.82-6.72 (4H, m); 6.19 (1H, s); 3.80 (6H, s); 3.71 (3H, s).
7-Hydroxy-4-(4-nitrophenyl)chromen-2-one (3af). Yellow crystals, mp >350ºC (lit. [32]
1
decomp. >360ºC), Rf 0.33 (petroleum ether–EtOAc, 5:2). H NMR, δ, ppm (J, Hz): (1H, s); 8.41-8.31 (2H, m);
.84-7.72 (2H, m); 7.17 (1H, d, J = 8.5); 6.81 (1H, d, J = 2.2); 6.76 (1H, dd, J = 8.5, J = 2. 2); 6.25 (1H, s).
7-Methoxy-4-methylcromen-2-one (3ba). White crystals, mp 156-157ºC (recrystallized from EtOH)
1
(lit. [30] 159ºC), Rf 0.79 (dichloromethane–methanol, 20:1). H NMR, δ, ppm (J, Hz): 7.49 (1H, d, J = 8.4);
6.68 (1H, dd, J = 8.4 and J = 2.6); 6.81 (1H,d, J = 2.6); 6.13 (1H, d, J = 1.0); 3.87 (3H, s); 2.39 (3H, d, J = 1.0).
GC–MS, m/z (Irel, %): 190 (82), 162 (88), 147 (100).
7-Methoxy-4-trifluoromethylcromen-2-one (3bb). White crystals, mp 113-114ºC (recrystallized from
EtOH–H2O) (lit. [33] 112ºC), Rf 0.71 (dichloromethane–methanol, 20:1). 1H NMR, δ, ppm (J, Hz): 7.63 (1H, dq,
J = 8.7 and JH–F = 1.8); 6.92 (1H, dd, J = 8.7 and J = 2.6); 6.88 (1H, d, J = 2.6); 6.62 (1H, s); 3.90 (3H, s).
19F NMR (DMSO-d6), δ -65.1. GC–MS, m/z (Irel, %): 244 (65), 216 (67), 201 (100).
3-Methoxy-7,8,9,10-tetrahydrobenzo[c]chromen-6-one (3bc). Yellow crystals, mp 119-120ºC
1
(recrystallized from EtOH–H2O) (lit. [34] 121ºC), Rf 0.65 (dichloromethane–methanol, 20:1). H NMR, δ,
ppm (J, Hz): 7.45 (1H, d, J = 8.5); 6.83 (1H, dd, J = 8.5 and J = 2.5); 6.80 (1H, d, J = 2.5); 3.86 (3H, s), 2.77-2.74
(2H, m); 2.56–2.53 (2H, m); 1.87-1.81 (4H, m). GC–MS, m/z (Irel, %): 230 (100), 215 (53), 202 (46), 174 (53).
7-Methoxy-4-phenylchromen-2-one (3bd). Off-white crystals, mp 108-109ºC (lit. [35] 110-111ºC),
1
Rf 0.66 (petroleum ether–EtOAc, 5:2). H NMR, δ, ppm (J, Hz): 7.61-7.46 (5H, m); 7.33 (1H, d, J = 8.8); 7.08
(1H, d, J = 2.5); 6.92 (1H, dd, J = 8.8, J = 2.5); 6.22 (1H, s); 3.85 (3H, s).
7-Methoxy-4-(3,4,5-trimethoxyphenyl)chromen-2-one (3be). Colorless crystals, mp 209-210ºC
1
(lit. [36] 172-175ºC (AcOH)), Rf 0.52 (dichloromethane–methanol, 20:1). H NMR, δ, ppm (J, Hz): 7.52 (1H, d,
J = 8.8); 7.07 (1H, d, J = 2.5); 6.92 (1H, dd, J = 8.8, J = 2.5); 7.80 (2H, s); 6.19 (1H, s); 6.28 (1H, s); 3.85 (3H, s);
3.80 (6H, s); 3.72 (3H, s).
7-Methoxy-4-(4-nitrophenyl)chromen-2-one (3bf). Grey crystals, mp 210-211ºC, Rf 0.62 (petroleum
1
ether–EtOAc, 5:2). H NMR, δ, ppm (J, Hz): 8.43-8.33 (2H, m); 7.85-7.75 (2H, m); 7.25 (1H, d, J = 8.9);
7.12 (1H, d, J = 2.6); 6.92 (1H, dd, J = 8.9, J = 2.6); 6.35 (1H, s); 3.86 (3H, s). Found, %: C 64.30; H 3.59; N 4.68.
C16H11NO5. Calculated, %: C 64.65; H 3.73; N 4.71.
7,8-Dihydroxy-4-methylcromen-2-one (3ca). Brownish crystals, mp 227-229ºC (recrystallized from
1
acetone–H2O) (lit. [30] 235ºC), Rf 0.27 (dichloromethane–methanol, 20:1). H NMR, δ, ppm (J, Hz): 10.37 (1H,
br s); 9.26 (1H, br s); 7.07 (1H, d, J = 8.4); 6.79 (1H, d, J = 8.4); 6.09 (1H, d, J = 1.1); 2.32 (3H, d, J = 1.1).
7,8-Dihydroxy-4-trifluoromethylchromen-2-one (3cb). Brownish crystals, mp 202-203ºC (lit. [29]
1
222-223ºC), Rf 0.26 (dichloromethane–methanol, 20:1). H NMR, δ, ppm (J, Hz): 10.51 (1H, br s); 9.59 (1H,
br s); 7.04 (1H, dq, J = 8.8, J = 2.1); 6.90 (1H, d, J = 8.8); 6.71 (1H, s).
3,4-Dihydroxy-7,8,9,10-tetrahydrobenzo[c]chromen-6-one (3cc). Dark yellow crystals, mp 254-256ºC
(recrystallized from EtOH–H2O) (lit. [37] 269–276ºC), Rf 0.31 (dichloromethane–methanol, 20:1). 1H NMR, δ, ppm
(J, Hz): 9.82 (1H, br s); 9.19 (1H, br s); 7.00 (1H, d, J = 8.4); 6.76 (1H, d, J = 8.4); 2.69–2.67 (2H, m); 2.41-2.35
(2H, m); 1.72-1.70 (4H, m).
7,8-Dihydroxy-4-phenylchromen-2-one (3cd). Brown needles, mp 191-193ºC (recrystallized from
1
EtOH–H2O) (lit. [9] 195-197ºC), Rf 0.24 (dichloromethane–methanol, 20:1). H NMR, δ, ppm (J, Hz): 7.57-7.40
(5H, m); 6.99 (1H, d, J = 8.8); 6.86 (1H, d, J = 8.8); 6.22 (1H, s).
7,8-Dihydroxy-4-(4-nitrophenyl)chromen-2-one (3cf). Yellow crystals, mp 291-294ºC (recrystallized
1
from EtOH–H2O) (lit. [32] 278ºC), Rf 0.19 (dichloromethane–methanol, 20:1). H NMR, δ, ppm (J, Hz):
8.40-8.28 (2H, m); 7.83-7.70 (2H, m); 6.77 (1H, d, J = 8.8); 6.63 (1H, d, J = 8.8); 6.22 (1H, s).
156