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ChemicalBook CAS DataBase List 5-Bromoisatoic anhydride
4692-98-2

5-Bromoisatoic anhydride synthesis

13synthesis methods
5-Bromoisatoic anhydride is prepared from 5-bromo indole by stirring in a 4:1 mixture of DMF/H2O for 16 h at room temperature.
1HNMR(DMSO-d6): ! 11.85 (s, br., 1H), 7.96 (dd, J = 0.8, 8.7 Hz, 1H), 7.87 (dd, J = 2.3, 8.7 Hz, 1H), 7.09 (dd, J = 8.8, 0.8 Hz, 1H).
32315-10-9 Synthesis
Triphosgene

32315-10-9
432 suppliers
$10.00/1g

5794-88-7 Synthesis
2-Amino-5-bromobenzoic acid

5794-88-7
478 suppliers
$6.00/10g

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Yield:4692-98-2 98%

Reaction Conditions:

with pyridine in dichloromethane;acetonitrile at 50 - 55; for 2 h;

Steps:

2.a
a) Preparation of 6-bromo-1H-benzo[d][1,3]oxazine-2,4-dione A solution of 2-amino-5-bromo-benzoic acid (280 g, 1.3 mol) in acetonitrile (1.3 l) was warmed up to 50-55° C. Pyridine (206 g, 2.61 mol) and a solution of triphosgene (128.8 g, 0.43 mol) in dichloromethane (720 ml) were simultaneously added dropwise. After completion of the addition, the mixture was stirred at 50-55° C. for an additional 2 h. The solvent was removed under reduced pressure and water was added. The precipitate was collected by filtration, successively washed with water and chilled dichloromethane, and then dried under vacuum to afford the desired product 6-bromo-1H-benzo[d][1,3]oxazine-2,4-dione (304 g, 98%). This material was used in the next step without further purification.

References:

Chen, Li;Chen, Shaoqing;Michoud, Christophe US2006/63804, 2006, A1 Location in patent:Page/Page column 11

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