Synthetic Route of 87-48-9, These common heterocyclic compound, 87-48-9, name is 5-Bromoindoline-2,3-dione, 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.
General procedure: A mixture of 2-bromoaniline or 3-bromoaniline (110 mmol, 18.9 g), chloral hydrate (118.8 mmol,19.6 g), anhydrous sodium sulfate (880 mmol, 125 g), and hydroxylamine hydrochloride (347.6mmol, 24.2 g) in water (700 mL) was heated under reflux for 25 min to form a yellow precipitate. 50mL of ethanol was added after that and left to boil for another 4 min before filtration. The resultedisonitrosoacetanilide was then heated with sulfuric acid (150 mL) at 70 C for about 10 min thenpoured into ice water to form an orange precipitate. When using 3-bromoaniline, an extra step ofseparation is required by solving the resulted mixture in 0.25 M NaOH (1 L), filtering it, then addingacetic acid (100 mL) to afford 4-bromoistain as a precipitate. 6-Bromoistin can be then obtained whenlowering the pH of the solution to 1 by hydrochloric acid 37%.All substituted bromo-isatins were methylated by stirring (22 mmol, 4.97 g) with sodiumhydride (2 mmol, 0.968 g) and dimethylsulfate (23.1 mmol, 2.19 mL) in dried DMF (50 mL) undernitrogen atmosphere. The resulting mixture was poured after 2 h in ice water (100 mL) to form anorange precipitate.The methylated bromo-isatins (2 mmol, 0.480 g) were treated after that with oxindole (2 mmol,0.226 g) in a 100:1 mixture of glacial acetic acid and hydrochloric acid 37% (12 mL) in reflux for about 3 h. Then, they were poured in ice water (50 mL) to afford 5-, 6- and 7-bromomeisoindigo. While 4′-, 5′-, 6′- and 7′-bromomeisoindigo were obtained by reacting unmethylated bromo-isatins(2 mmol, 0.452 g) with 1-methyloxindole (2 mmol, 0.294 g) in the same conditions. The resultedprecipitates were washed with water, ethanol (2 x 10 mL), and diethylether (2 10 mL) then dried. 3.2.1. 5-Bromo-1-MeisoindigoYield: 70%. 1H-NMR (400 MHz, DMSO, d6) delta ppm 3.19 (s, 3H), 6.83 (dd, 3J = 7.8 Hz, 4J = 0.5 Hz, 1H)6.96 (m, 1H), 6.97 (d, 3J = 8.4 Hz, 1H), 7.35 (td, 3J = 7.6 Hz, 4J = 1.1 Hz), 7.58 (dd, 3J = 8.4 Hz, 4J = 2.1 Hz),9.06 (dd, 3J = 8.1 Hz, 4J = 0.5 Hz), 9.31 (d, 4J = 2.0 Hz, 1H), 10.94 (s, 1H). 13C-NMR (100 MHz, DMSO,d6) delta ppm 26.6, 110.2, 110.7, 114.0, 121.8, 121.9, 123.0, 130.2, 131.1, 131.5, 133.8, 134.8, 135.6, 144.4, 145.0,167.2, 169.3. Anal. calcd. for C17H11BrN2O2: C 57.49, H 3.12, N 7.89; found: C 57.44, H 3.18, N 793.HRMS (ESI) calculated m/z: 376.9896; found C17H11BrN2O2; m/z: 376.9896 [M + H]+.
The synthetic route of 87-48-9 has been constantly updated, and we look forward to future research findings.
Reference:
Article; Tegethoff, Jana; Bischoff, Roland; Saleh, Sawsan; Blagojevic, Biljana; Merz, Karl-Heinz; Cheng, Xinlai; Molecules; vol. 22; 9; (2017);,
Indoline – Wikipedia,
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