These common heterocyclic compound, 32692-19-6, name is 5-Nitroindoline, 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. Application In Synthesis of 5-Nitroindoline
29: 3-(5-Nitroindolin-1 -yl)phenyl 2,3,4,6-tetra-O-acetyl-a-D-mannopyranoside (16)A dry Schlenk tube is charged with Cs2C03 (266 mg, 0.816 mmol, 3 equiv). The tube is evacuated for 30 min and then flushed with argon gas and 3-iodophenyl 2,3,4,6-tetra-O- acetyl-a-D-mannopyranoside 15 (150 mg, 0.272 mmol, 1 equiv) is added to the tube, followed by Pd2(dba)3 (2.8 mg, 0.0027 mmol, 0.01 equiv) and X-Phos (6.5 mg, 0.0136 mmol, 0.05 equiv). The mixture is dissolved in dry dioxane (5 mL). The solvent is degassed in a ultrasonic bath for 20 min. Then 5-nitroindoline (67.3 mg, 0.41 mmol, 1 .5 equiv) is added. The mixture is heated to 80C and stirred for 53 h. TLC (petroleum ether/ EtOAc 3:1 ) and mass spectroscopy helps monitoring the reaction and indicates formation of partially deacetylated mannoside during the progress of the reaction. For that reason dry pyridine (2 mL) and dry acetic anhydride (1 mL) are added 50 h after reaction start to regain fully protected mannoside. Then EtOAc (30 mL) and saturated aqueous NaHC03 solution (50 mL) are added to the reaction mixture. The layers are separated and the organic phase is washed with brine (2 x 50 mL). The aqueous layers are extracted with EtOAc (3 x 30 mL). The combined organic layers are dried with Na2S04, filtered and concentrated under reduced pressure. The residue is purified with silica gelchromatography (petroleum ether/EtOAc, gradient from 10:1 to 1 :1 ). Compound 16 (128 mg, 80%) is obtained as an orange solid.[a]D20 + 59.3 (c = 1 , CHCI3); 1H NMR (CDCI3): delta 2.02 (m, 9H, OAc), 2.20 (s, 3H, OAc), 3.21 (t, J = 8.5 Hz, 2H, CH2), 4.1 1 (m, 4H, CH2, H-6a, H-5), 4.26 (dd, J = 7.3 Hz, 1 H, H-6b), 5.37 (t, J = 9.9 Hz, 1 H, H-4), 5.43 (s, 1 H, H-2), 5.53 (m, 2H, H-1 , H-3), 6.84 (d, J = 8.3 Hz, 1 H, C6H4), 6.98 (m, 3H, C6H4, C6H3), 7.30 (t, J = 8.1 Hz, 1 H, C6H4), 8.00 (s, 1 H, C6H3), 8.05 (d, J = 8.8 Hz, 1 H, C6H3); 13C-NMR (CDCI3): delta 20.89, 20.92, 20.94, (3 OAc), 21.12 (OAc), 27.29 (CH2), 53.36 (CH2), 62.30 (C-6), 66.07 (C-4), 69.01 (C-3), 69.54, 69.56 (2C, C-2, C-5), 96.00 (C-1 ), 106.66, 107.96, 1 1 1.47, 1 14.09, 121.37, 126.13,130.70 (8C, arom. C), 143.38 (1 C, arom. C-O) 152.64, (1 C, arom. C-N), 169.92, 170.23, 170.25, 170.71 (4 C=0)
The synthetic route of 5-Nitroindoline has been constantly updated, and we look forward to future research findings.
Reference:
Patent; UNIVERSITY OF BASEL; ERNST, Beat; HEROLD, Janno; WO2011/73112; (2011); A2;,
Indoline – Wikipedia,
Indoline | C8H9N – PubChem