Reaction equation
C(O[CH2:8][N:9]1[C:13](=[O:14])[C:12]2[C:15]([CH:21]([CH3:23])[CH3:22])=[CH:16][C:17]([O:19][CH3:20])=[CH:18][C:11]=2[S:10]1(=[O:25])=[O:24])(=O)C(C)(C)C.[BrH:26]>C(O)(=O)C.O>[Br:26][CH2:8][N:9]1[C:13](=[O:14])[C:12]2[C:15]([CH:21]([CH3:23])[CH3:22])=[CH:16][C:17]([O:19][CH3:20])=[CH:18][C:11]=2[S:10]1(=[O:25])=[O:24]Participants
Reactant 2
Product 1
Reagents, catalysts & solvents 2
Procedure
A solution of 2-(pivaloyloxymethyl)-4-isopropyl-6-methoxy-1,2-benzisothiazol-3(2H)-one 1,1-dioxide (1.33 kg, 3.62 mol), 48% HBr in acetic acid (1 L) and 3 L of acetic acid was stirred on a steam bath (90°-95° C.) for 1.5 hours. The solvent (acetic acid) was removed under vacuum to give a thick slurry of an off-white residue which was diluted with 10 L of cold water and stirred for 30 minutes. The crude product was collected by filtration, washed first with 6 L of water and then with 3 L of saturated sodium bicarbonate solution. The crude solid was dried at 60°-70° C. for 20 hours and then was recrystallized from a mixture of 5 L of ethyl acetate and 6 L of hexane. Two crops were collected to give 1.16 kg (92%) of 2-bromomethyl-4-isopropyl-6-methoxy-1,2-benzisothiazol-3(2H)-one 1,1-dioxide, as an off-white solid, m.p. 157°-159° C.
Workup
- customThe solvent (acetic acid) was removed under vacuum
- customto give a thick slurry of an off-white residue which
- filtrationThe crude product was collected by filtration
- washwashed first with 6 L of water
- customThe crude solid was dried at 60°-70° C. for 20 hours
- customwas recrystallized from a mixture of 5 L of ethyl acetate and 6 L of hexane
- customTwo crops were collected
Sources & evidence
- ORD record
- ord-4d2db28ea1bf453b8f46945b4e4be9d4
- Source dataset
- uspto-grants-1998_05
- Patent number
- US05750550
Linked notes
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