KIVRAK et al./Turk J Chem
3.1.1.4. 4-Methoxy-2-(prop-2-ynyloxy)benzaldehydes (3d)
Purification by filtration afforded the product as a light yellow (yield: 92%): 1 H NMR (400 MHz, CDCl3) δ
10.49 (s, 1H, aldehyde), 7.47–7.45 (m, 1H), 7.17–7.15 (m, 2H), 4.87 (s, 2H, CH2), 3.88 (s, 3H, OMe), 2.47 (s,
1H, alkyne); 13 C NMR (100 MHz, CDCl3) δ 190.6, 152.8, 152.6, 131.2, 124.9, 118.8, 117.6, 78.2, 76.9, 60.8,
56.0. IR (ATR) 3281 (acetylenic H), 2936, 2119 (triple bond), 1688 (carbonyl), 1588, 1472, 1412, 1345, 1273,
1062, 1065, 990, 785. The spectral data were in agreement with those reported previously for this compound.47
3.1.1.5. 2-(Ethynyloxy)-1-naphthaldehyde (3e)
Purification by filtration afforded the product as a light yellow (yield: 70%): 1 H NMR (400 MHz, CDCl3) δ
10.9 (s, 1H, aldehyde), 9.27 (d, J = 8.7 Hz, 1H), 8.09–8.06 (m, 1H), 7.81–7.79 (m, 1H), 7.65–7.63 (m, 1H),
7.45–7.43 (m, 1H), 7.39–7.36 (m, 1H), 4.94 (s, 2H, CH2), 2.77 (t, J = 2.3 Hz, 1H, alkyne’s H). 13 C NMR (100
MHz, CDCl3) δ 191.7, 161.9, 137.3, 131.4, 129.9, 129.1, 128.2, 125.2, 125.1, 118.0, 113.9, 77.6, 76.7, 57.4. IR
(ATR) 3258 (acetylenic H), 2966, 2123 (triple bond), 1696 (carbonyl), 1495, 1363, 1177, 1227, 1062, 1001, 985,
740. The spectral data were in agreement with those reported previously for this compound.46
3.1.2. General procedure for the synthesis of 1-(2-(but-3-ynyl)benzylidene)-2-methylhydrazines
The corresponding 2-(prop-2-ynyloxy)benzaldehydes 3 (0.5 mmol) were dissolved in dioxane (2 mL). Then
methylhydrazine (2 mL) was added at room temperature. The resulting mixture was flushed with argon and
stirred at room temperature for 1 h. After the reaction was over, the solvent was removed under vacuum and
the residue was purified by column chromatography over silica gel with hexane-EtOAc (9:1) to afforded the
desired hydrazones.
3.1.2.1. 1-(2-(But-3-ynyl)benzylidene)-2-methylhydrazine (4a)
The product was isolated as a brown oil (yield: 98%): 1 H NMR (400 MHz, CDCl3) δ 7.87 (s, 1H, CH = N),
7.81 (dd, J = 8.0 and 1.9 Hz, 1H), 7.22–7.19 (m, 1H), 6.98–6.97 (m, 2H), 5.60 (brs, 1H, NH), 4.70 (d,J = 2.4
Hz, 2H, CH2), 2.94 (s, 3H, NHCH3), 2.59 (s, 1H, alkyne’s H); 13 C NMR (100 MHz, CDCl3) δ 154.6, 139.2,
130.9, 128.6, 125.3, 121.8, 112.7, 78.6, 75.7, 56.3, 34.9. IR (ATR) 3284 (acetylenic H), 2960, 2866, 2793, 2116
(triple bond), 1600, 1483, 1463, 1223, 1098, 1021, 762.
3.1.2.2. 1-(5-Bromo-2-(but-3-ynyl)benzylidene)-2-methylhydrazine (4b)
The product was isolated as a brown oil (yield: 85%): 1 H NMR (400 MHz, CDCl3) δ 7.94 (d, J = 2.5 Hz,
1H), 7.72 (s, 1H, CH = N), 7.28 (dd, J = 8.7 and 2.5 Hz, 1H), 6.86 (d, J = 8.8 Hz, 1H), 4.70 (d, J = 2.4,
2H, CH2), 2.96 (s, 3H, NHCH3), 2.52 (t, J = 2.4 Hz, 1H, alkyne’s H); 13 C NMR (100 MHz, CDCl3) δ 153.4,
136.9, 130.8, 128.6, 127.8, 118.2, 114.5, 78.1, 76.0, 56.5, 34.7. IR (ATR) 3290 (acetylenic H), 2980, 2920, 2797,
2120 (triple bond), 1594, 1475, 1406, 1224, 1115, 1020, 799, 633.
3.1.2.3. 1-(2-(But-3-ynyl)-5-nitrobenzylidene)-2-methylhydrazine (4c)
The product was isolated as a brown oil (yield: 84%): 1 H NMR (400 MHz, CDCl3) δ 8.70–8.67 (m, 1H),
8.09–8.07 (m, 1H), 7.68 (s, 1H, CH = N), 7.06–7.04 (m, 1H), 5.93 (brs, 1H, NH), 4.83 (s, 2H, CH2), 3.00 (s,
313