Paper
1H NMR (500 MHz, DMSO-d6) δ: 7.53 (d, J = 8.3 Hz, 2H),
Photochemical & Photobiological Sciences
13C NMR (126 MHz, DMSO-d6) δ: 167.79, 148.08, 146.86,
7.17 (d, J = 8.2 Hz, 2H), 6.85 (d, J = 12.9 Hz, 1H), 5.89 (d, J = 141.97, 126.16, 124.90, 116.95, 114.94, 114.33, 55.46.
12.9 Hz, 1H), 2.31 (s, 3H).
UV-vis (solvent) λmax (nm) (log ε): (MeCN) 317 (4.05), 296 (s).
Z-3,4-Dihydroxycinnamic acid (4b). 1H NMR (500 MHz,
DMSO-d6) δ: 9.33 (s, 1H), 8.98 (s, 1H), 7.32 (d, J = 2.1 Hz, 1H),
7.01 (dd, J = 8.2, 2.1 Hz, 1H), 6.72–6.63 (m, 2H), 5.68 (d, J =
12.9 Hz, 1H).
13C NMR (126 MHz, DMSO-d6) δ: 167.55, 140.55, 138.57,
132.02, 129.72, 128.65, 120.00, 20.93.
UV-vis (solvent) λmax (nm) (log ε): (MeCN) 276 (4.04).
−
HRMS negative ion mode m/z: [M − H]− calcd for C10H9O2
161.0608, found 161.0604.
13C NMR (126 MHz, DMSO-d6) δ: 167.63, 146.95, 144.54,
Z-Cinnamic acid (2d) (Table 1, entry 4). Solid, m.p.: 141.70, 126.21, 123.20, 117.58, 116.74, 114.95.
55–57 °C.35 Z-3-Hydroxycinnamic acid (4c). 1H NMR (500 MHz, DMSO-
1H NMR (500 MHz, DMSO-d6) δ: 7.58 (m, 2H), 7.35 (m, 3H), d6) δ: 9.46 (s, 1H), 7.14 (t, J = 7.9 Hz, 1H), 7.03 (m, 1H), 6.97
6.90 (d, J = 12.7 Hz, 1H), 5.96 (d, J = 12.7 Hz, 1H).
13C NMR (126 MHz, DMSO-d6) δ: 167.51, 140.33, 134.90,
129.51, 128.80, 128.08, 121.11.
UV-vis (solvent) λmax (nm) (log ε): (MeCN) 264 (3.96).
Z-4-Fluorocinnamic acid (2e). Solid, m.p.: 76–78 °C.
1H NMR (500 MHz, DMSO-d6) δ: 7.70 (dd, J = 8.6, 5.7 Hz,
(m, 1H), 6.75 (m, 2H), 5.91 (d, J = 12.8 Hz, 1H).
13C NMR (126 MHz, DMSO-d6) δ: 167.72, 156.99, 139.36,
136.19, 129.01, 121.32, 120.40, 116.03, 115.81.
Z-3-Hydroxy-4-methoxycinnamic acid (6a). Solid, m.p.:
101–103 °C.
1H NMR (500 MHz, DMSO-d6) δ: 9.03 (s, 1H), 7.28 (d, J =
2H), 7.20 (t, J = 8.9 Hz, 2H), 6.91 (d, J = 12.8 Hz, 1H), 6.95 (d, J 2.1 Hz, 1H), 7.10 (dd, J = 8.4, 2.1 Hz, 1H), 6.90 (d, J = 8.4 Hz,
= 12.7 Hz, 1H).
1H), 6.71 (d, J = 12.9 Hz, 1H), 5.76 (d, J = 12.8 Hz, 1H), 3.78 (s,
13C NMR (126 MHz, DMSO-d6) δ: 167.32, 162.16 (d, J = 3H).
246.9 Hz), 139.69, 132.04 (d, J = 8.5 Hz), 131.34 (d, J = 3.2 Hz),
13C NMR (126 MHz, DMSO-d6) δ: 167.64, 148.71, 145.73,
120.77, 114.97 (d, J = 21.5 Hz).
141.04, 127.64, 122.62, 118.03, 117.07, 111.37, 55.58.
UV-vis (solvent) λmax (nm) (log ε): (MeCN) 304 (4.30).
HRMS negative ion mode m/z: [M − H]− calcd for C10H9O4
193.0506, found 193.0514.
UV-vis (solvent) λmax (nm) (log ε): (MeCN) 265 (3.97).
HRMS negative ion mode m/z: [M − H]− calcd for C9H6FO2
165.0357, found 165.0349.
−
−
Z-4-Chlorocinnamic acid (2f). Solid, m.p.: 110–112 °C.
Z-3,4-Dimethoxycinnamic acid (6b). 1H NMR (500 MHz,
1H NMR (500 MHz, DMSO-d6) δ: 7.62 (d, J = 8.5 Hz, 2H), DMSO-d6) δ: 7.62 (d, J = 2.1 Hz, 1H), 7.24 (dd, J = 8.5, 2.0 Hz,
7.43 (d, J = 8.5 Hz, 2H), 6.91 (d, J = 12.7 Hz, 1H), 6.00 (d, J = 1H), 6.95 (d, J = 8.4 Hz, 1H), 6.80 (d, J = 12.9 Hz, 1H), 5.80 (d,
12.7 Hz, 1H).
J = 12.9 Hz, 1H), 3.78 (s, 3H), 3.74 (s, 3H).
13C NMR (126 MHz, DMSO-d6) δ: 167.23, 139.41, 133.75,
133.36, 131.35, 128.08, 121.74.
13C NMR (126 MHz, DMSO-d6) δ: 167.72, 149.77,
147.91, 141.39, 127.43, 124.29, 118.08, 113.53, 111.03, 55.50,
55.33.
UV-vis (solvent) λmax (nm) (log ε): (MeCN) 269 (4.10).
HRMS negative ion mode m/z: [M
−
H]− calcd for
Z-3-Methoxycinnamic acid (6c). Solid, m.p.: 39–41 °C.
1H NMR (500 MHz, DMSO-d6) δ: 7.27 (m, 2H), 7.13 (d, J =
7.6 Hz, 1H), 6.91 (dd, J = 8.0, 2.6 Hz, 1H), 6.86 (d, J = 12.8 Hz,
C9H6ClO2− 181.0062, found 181.0061.
Z-4-Bromocinnamic acid (2g). Solid, m.p.: 124–126 °C.
1H NMR (500 MHz, DMSO-d6) δ: 7.56 (q, J = 8.7 Hz, 4H), 1H), 5.97 (d, J = 12.8 Hz, 1H), 3.75 (s, 3H).
6.89 (d, J = 12.7 Hz, 1H), 6.00 (d, J = 12.7 Hz, 1H).
13C NMR (126 MHz, DMSO-d6) δ: 167.58, 158.86, 139.77,
13C NMR (126 MHz, DMSO-d6) δ: 167.24, 139.48, 134.12, 136.16, 129.12, 122.03, 121.37, 114.73, 114.49, 55.03.
131.56, 131.02, 122.11, 121.84.
UV-vis (solvent) λmax (nm) (log ε): (MeCN) 267 (3.91).
HRMS negative ion mode m/z: [M − H]− calcd for C10H9O3
−
UV-vis (solvent) λmax (nm) (log ε): (MeCN) 268 (4.11).
HRMS negative ion mode m/z: [M
−
H]− calcd for 177.0557, found 177.0561.
C9H6BrO2− 224.9557, found 224.9562.
Z-4-Nitrocinnamic acid (2h). Solid, m.p.: 137–139 °C.
1H NMR (500 MHz, DMSO-d6) δ: 8.22 (d, J = 8.8 Hz, 2H),
7.76 (d, J = 8.7 Hz, 2H), 7.08 (d, J = 12.6 Hz, 1H), 6.18 (d, J =
12.6 Hz, 1H).
Conflicts of interest
There are no conflicts to declare.
13C NMR (126 MHz, DMSO-d6) δ: 166.89, 146.96, 141.86,
138.42, 130.32, 124.51, 123.15.
UV-vis (solvent) λmax (nm) (log ε): (MeCN) 293 (4.11).
Acknowledgements
HRMS negative ion mode m/z: [M
−
H]− calcd for
C8H6NO2− 192.0302, found 192.0306.
The authors are grateful to the University of Buenos Aires
Z-4-Hydroxy-3-methoxycinnamic acid (4a). Solid, m.p.: (UBACyT 20020170100110BA), the Consejo Nacional de
108–111 °C.35
Investigación Científica y Técnica (CONICET PIP 0072CO) and
1H NMR (500 MHz, DMSO-d6) δ: 9.47 (s, 1H), 7.65 (d, J = 2.0 to the Agencia Nacional de Promoción Científica y Tecnológica
Hz, 1H), 7.15 (dd, J = 8.2, 2.0 Hz, 1H), 6.80–6.71 (m, 2H), 5.73 (PICT 2016-0130) for the financial support. MLS and REB are
(d, J = 13.0 Hz, 1H), 3.76 (s, 3H).
Research Members of CONICET (Argentina).
Photochem. Photobiol. Sci.
This journal is © The Royal Society of Chemistry and Owner Societies 2020