A common heterocyclic compound, 3484-35-3, name is 5-Methylindolin-2-one, molecular formula is C9H9NO, its traditional synthetic route has been very mature, but the traditional synthetic route has various shortcomings, such as complicated route, low yield, poor purity, etc, below Introduce a new synthetic route. 3484-35-3.
General procedure: 3-(Propan-2-yliden)indolin-2-one (7a): A solution of indolin-2-one (500 mg, 3.76 mmol, 1.0 equiv.) in acetone (15 mL, 0.25 M) was heated in the presence of catalytic amounts of morpholine (164 mL, 164 mg, 1.88 mmol, 0.5 equiv.) for 16 h at reflux temperature. After complete consumption of the indolin-2-one (determined by thin layer chromatography (TLC)) all volatiles were removed under vacuum. Column chromatography(column diameter 5 cm, 30 g silica, v/v (P/EA)6 : 4-1 : 1) afforded the title compound (650 mg, 3.75 mmol, 99 %) as a yellow solid. Apparent multiplets which occur as a result of accidental equality of coupling constants to those of magnetically non-equivalent protons are marked as virtual (virt.). RF 0.70 (P/EA3 : 7; UV). deltaH (CDCl3, 250 MHz,300 K) 7.96 (1H, br s, NH), 7.52 (1H, br d, 3J 7.7, H-4), 7.19(1H, virt. td, 3JE3J 7.7, 4J 1.2, H-6), 7.01 (1H, virt. td, 3JE3J7.7, 4J 1.2, H-5), 6.85 (1H, ddd, 3J 7.7, 4J 1.2, 5J 0.6, H-7), 2.62(3H, s, H-30), 2.39 (3H, s, H-1′). deltaC (CDCl3, 63 MHz, 300 K)169.5 (s, C-2), 155.7 (s, C-2′), 139.3 (s, C-7a), 127.7 (d, C-6),124.6 (s, C-3), 123.9 (d, C-5), 123.0 (s, C-3a), 121.8 (d, C-4),109.3 (d, C-7), 25.4 (q, C-1′), 23.3 (q, C-3′). The NMR data match the values reported in the literature.[9] 5-Methyl-3-(propan-2-ylidene)indolin-2-one (7h): Prepared from 5-methyl-2-oxindole according to RP 1 on a 924 mmol scale. The title compound (110 mg, 587 mmol, 63 %) was obtained as an orange solid. RF 0.67 (P/EA1 : 1; UV). numax (ATR)/cm1 3167br (NH), 3148w, 3025m, 2913w, 2858w,1698vs (CO), 1614s, 1480vs, 1316m, 1249m, 1211m. deltaH(CDCl3, 250 MHz, 300 K) 8.12 (1H, br s, NH), 7.34 (1H, br s,H-4), 7.01 (1H, br d, 3J 7.8, H-6), 6.77 (1H, d, 3J 7.8, H-7), 2.61(3H, s, CH3), 2.39 (3H, s, H-30), 2.36 (s, 3H, H-10). deltaC (CDCl3,63 MHz, 300 K) 169.5 (s, C-2), 156.2 (s, C-3′), 136.7 (s, C-7a),131.0 (s, C-5), 128.0 (d, C-6), 124.5 (s, C-4), 124.4 (d, C-3),122.9 (s, C-3a), 109.1 (d, C-7), 25.4 (q,CH3), 23.3 (q, C-1′), 21.4(q, C-3′). m/z (HRMS ESI) 188.1070; [M H](C12H13NO)requires 188.1017.
The synthetic route of 5-Methylindolin-2-one has been constantly updated, and we look forward to future research findings.
Reference:
Article; Maturi, Mark M.; Poethig, Alexander; Bach, Thorsten; Australian Journal of Chemistry; vol. 68; 11; (2015); p. 1682 – 1692;,
Indoline – Wikipedia,
Indoline | C8H9N – PubChem