Molecules 2020, 25, 3082
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(Z)-3-(2-(p-Tolyl)hydrazono)indolin-2-one (1Z). Orange solid, (725 mg, 85%) 1H-NMR (DMSO-d6),
: 12.76 (s, 1H), 11.00 (s, 1H), 7.54 (d, J = 7.4 Hz, 1H), 7.32 (d, J = 8.4 Hz, 2H), 7.24 (td, J = 7.7,
δ
1.1 Hz, 1H), 7.18 (d, J = 8.3 Hz, 2H), 7.05 (td, J = 7.5, 0.7 Hz, 1H), 6.93 (d, J = 7.7 Hz, 1H), 2.28 (s,
3H). 13C-NMR (DMSO-d6)
δ 163.21, 140.20, 132.01, 129.89, 128.20, 127.00, 121.77, 121.25, 118.42, 114.06,
(Z)-3-(2-(2-Nitrophenyl)hydrazono)indolin-2-one (2Z). Orange solid, (729 mg, 76%) 1H-NMR
(DMSO-d6), δ: 14.27 (s, 1H), 11.18 (s, 1H), 8.22 (ddd, J = 8.5, 4.7, 1.1 Hz, 1H), 7.82 (dd, J = 11.5,
4.2 Hz, 1H), 7.66 (d, J = 7.2, 1H), 7.34 (td, J = 7.7, 1.2 Hz, 1H), 7.18 (ddd, J = 8.4, 7.1, 1.2 Hz, 1H), 7.10 (td,
J = 7.6, 0.8 Hz, 1H), 6.95 (d, J = 7.8, 1H). 13C-NMR (DMSO-d6),
δ: 163.28, 147.31, 142.53, 140.11, 137.21,
137.02, 134.36, 125.16, 125.03, 124.31, 124.02, 115.84. [17]
(E)-3-(2-(2-Nitrophenyl)hydrazono)indolin-2-one (2E). Orange solid, (652 mg, 68%) 1H-NMR
(DMSO-d6),
7.91-7.79 (m, 2H), 7.44 (td, J = 7.7, 0.8 Hz, 1H), 7.20 (tdd, J = 7.5, 6.4, 1.0 Hz, 2H), 6.98 (d, J = 7.8, 1H).
13C-NMR (DMSO-d6),
: 167.63, 146.66, 144.60, 141.70, 138.56, 138.06, 135.69, 127.41, 126.70, 125.54,
δ: 11.57 (s, 1H), 10.82 (s, 1H), 8.24 (dd, J = 8.5, 1.3 Hz, 1H), 8.04 (dd, J = 8.5, 1.0 Hz, 1H),
δ
125.25, 116.07. Elem. anal. calcd. for C14H10N4O3: C 59.57, H 3.57; N 19.85. found: C 59.61; H 3.55; N
19.88. m. IR (ATR) ν/cm−1: 3333, 3085, 2360, 1751, 1610, 1318, 1281, 726. p.: 269–271 ◦C.
1
(Z)-3-(2-(2,4-Dinitrophenyl)hydrazono)indolin-2-one (3Z). Orange solid, (367 mg, 33%) H-NMR
(DMSO-d6),
J = 9.5 Hz, 1H), 7.71 (d, J = 7.4 Hz, 1H), 7.46–7.36 (td, J = 7.7, 1.3 Hz, 2H), 7.13 (td, J = 7.6, 0.9 Hz, 2H),
6.98 (d, J = 7.8 Hz, 1H). 13C-NMR (DMSO-d6)
: 161.34, 141.72, 141.21, 137.53, 136.53, 131.52, 130.11,
129.47, 121.52, 120.35, 120.17, 114.41, 113.22, 110.17 [18]
(E)-3-(2-(2,4-Dinitrophenyl)hydrazono)indolin-2-one (3E). Orange solid, (411 mg, 37%) H-NMR
(DMSO-d6), : 11.75 (s, 1H), 10.95 (s, 1H), 8.93 (d, J = 2.6 Hz, 1H), 8.61 (dd, J = 9.5, 2.6 Hz, 1H), 8.16 (d,
J = 9.5 Hz, 1H), 7.90 (d, J = 7.6 Hz, 1H), 7.49 (t, J = 7.4 Hz, 1H), 7.22 (t, J = 7.7 Hz, 1H), 7.00 (d, J = 7.7 Hz,
1H). 13C-NMR (DMSO-d6)
: 164.07, 143.98, 143.85, 139.79, 138.73, 133.32, 132.24, 130.47, 123.77, 122.49,
δ: 14.53 (s, 1H), 11.32 (s, 1H), 8.94 (d, J = 2.5 Hz, 1H), 8.55 (dd, J = 9.2, 2.3 Hz, 1H), 8.35 (d,
δ
1
δ
δ
122.17, 116.82, 115.17, 111.30. Elem. anal. calcd. for C14H9N5O5: C 51.38, H 2.77; N 21.40. found: C
51.43; H 2.81; N 21.37. IR (ATR) ν/cm−1: 3318, 3067, 2360, 1728, 1609, 1310, 1277, 738. m.p.: >300 ◦C.
3.2.2. Synthesis of Compounds 5 and 6
A solution of oxindole (500 mg, 3.75 mmol) and triethyl orthoformate (4.86 mL, 29.3 mmol) in
acetic acid (10 mL) was refluxed for 1.5 h. After cooling the volume was reduced and the oily mixture
was dissolved in ethanol (20 mL). The volume was reduced to half after cooling to 10 ◦C the precipitate
was filtered off, washed with cold ethanol (2
for the next step without purification.
×
10 mL), and dried under vacuo. The product was used
A solution of (ethoxymethylene)indolin-2-one (600 mg, 3 mmol) and the corresponding aniline
(3 mmol), HCl (0.1 mL) in ethanol (5 mL) was refluxed for 2 h. After cooling, the precipitated solid was
filtered off, washed with ethanol (10 mL), ether (10 mL), and dried under vacuo.
(E)-3-[(Phenylamino)methylene]indolin-2-one (4 δ
). Red solid (530 mg, 75%) 1H-NMR (DMSO-d6)
10.70 (d, J = 12.5 Hz, 1H), 10.48 (s, 1H), 8.58 (d, J = 12.5 Hz, 1H), 7.57 (d, J = 7.5 Hz, 1H), 7.38–7.34 (m,
4H), 7.08-7.03 (m, 1H), 6.99 (td, J = 7.6, 1.0 Hz, 1H), 6.91 (td, J = 7.5, 0.8 Hz, 1H), 6.83 (d, J = 7.6 Hz, 1H)
ppm. 13C-NMR (DMSO-d6)
δ
170.32, 140.38, 138.35, 137.39, 130.09, 124.66, 124.46, 123.48, 120.79, 117.50,
117.37, 116.28, 109.57, 100.08 ppm. IR (ATR) ν/cm−1: 3131, 1678, 1580, 1269, 937. [19]
(E)-3-[((4-Nitrophenyl)amino)methylene]indolin-2-one (
). Red solid (360 mg, 72%) 1H-NMR
5
(DMSO-d6) δ 10.95 (d, J = 12.1 Hz, 1H), 10.62 (s, 1H), 8.64 (d, J = 12.1 Hz, 1H), 8.22 (d, J = 9.0 Hz, 2H),
7.60 (t, J = 9.1 Hz, 3H), 7.06 (t, J = 7.4 Hz, 1H), 6.94 (t, J = 7.4 Hz, 1H), 6.84 (d, J = 7.6 Hz, 1H). 13C-NMR
(DMSO-d6)
δ 170.18, 146.50, 142.10, 138.37, 136.21, 126.17, 126.05, 125.87, 123.95, 121.19, 118.48, 116.68,
116.13, 109.89, 103.90 ppm. Elem. anal. calcd. for C15H11N3O3: C 64.05, H 3.94; N 14.94. found:
C 64.21; H 3.99; N 14.89. IR (ATR) ν/cm−1: 3163, 2360, 1692, 1577, 1308, 1278, 839. m.p.: >300 ◦C.