4,6-DICHLORO-1H-INDOLE-2,3-DIONE synthesis
- Product Name:4,6-DICHLORO-1H-INDOLE-2,3-DIONE
- CAS Number:18711-15-4
- Molecular formula:C8H3Cl2NO2
- Molecular Weight:216.02
18711-11-0
18711-15-4
General procedure for the synthesis of 4,6-dichlorodihydroindole-2,3-dione from 2-hydroxyimino-N-(3,5-dichlorophenyl)-acetamide: 1. Preparation of intermediate I-2: Intermediate I-1 (10.0 g, 42.9 mmol) prepared above was slowly added to concentrated hydrochloric acid. Under ice bath conditions, sulfuric acid (50 mL) was added to ensure that the temperature of the reaction mixture was kept below 50 °C. 2. After the reaction was complete, the dark colored solution was heated at 90 °C for 10 min. 3. The reaction mixture was cooled to room temperature and then poured into 10 times the volume of ice and stirred vigorously for 1 hour. 4. The insoluble solid formed was collected, washed with water and dried under vacuum to give 4,6-dichlorodihydroindole-2,3-dione (8.90 g, 96% yield) as an orange solid. - TLC Rf = 0.4 (EtOAc:hexane=1:3) - Melting point: 228-230°C - 1H NMR (DMSO-d6) δ: 6.97 (d, J=1.8Hz, 1H, ArH), 7.32 (d, J=1.8Hz, 1H, ArH), 11.42 (br s, 1H, NH) - MS (EI) m/e: 216 [M+], 188 [M+-CO2], 160.
18711-11-0
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18711-15-4
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Yield:18711-15-4 96%
Reaction Conditions:
with sulfuric acid at 0 - 90;
Steps:
1.2
2) Intermediate I-2; 4,6-dichloro-1H-indole-2,3-dione; The Intermediate I-1 (10.0 g, 42.9 mmol) prepared by the above preparation example I(1) was slowly added to conc. sulfuric acid (50 mL) in an ice bath. At this moment, the temperature of the reaction mixture was maintained below 50°C. After complete the addition, the solution of dark color was heated for 10 minutes at 90 °C. After cooling down the resultant to room temperature, the reactant was poured into ice having 10 times of the reactant volume, and was vigorously stirred for 1 hour. The insoluble solid formed in the above procedure was collected, washed with water, dried in vacuo, and the objective compound (8.90 g, 96 %) was obtained as orange-colored solid: TLC Rf = 0.4 (EtOAc:n-hexane = 1:3); mp 228-230 ; 1H NMR (DMSO-d6) δ 6.97 (d, J = 1.8 Hz, 1H, ArH), 7.32 (d, J = 1.8 Hz, 1H, ArH), 11.42 (br s, 1H, NH); MS (EI) m/e 216[M+], 188 [M+-CO2], 160.
References:
EP1650190,2006,A1 Location in patent:Page/Page column 10
626-43-7
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18711-15-4
93 suppliers
$9.00/250mg