Hydrochloric Acid → 2-(Benzo[1,2,5]thiadiazole-4-sulfonylamino)-4-chlorobenzoic acid
Reaction equation
C[O:2][C:3](=[O:24])[C:4]1[CH:9]=[CH:8][C:7]([Cl:10])=[CH:6][C:5]=1[NH:11][S:12]([C:15]1[C:20]2=[N:21][S:22][N:23]=[C:19]2[CH:18]=[CH:17][CH:16]=1)(=[O:14])=[O:13].[Li+].[OH-].Cl>C1COCC1>[N:23]1[S:22][N:21]=[C:20]2[C:15]([S:12]([NH:11][C:5]3[CH:6]=[C:7]([Cl:10])[CH:8]=[CH:9][C:4]=3[C:3]([OH:24])=[O:2])(=[O:14])=[O:13])=[CH:16][CH:17]=[CH:18][C:19]=12Participants
Procedure
To a stirred suspension of 2-(benzo[1,2,5]thiadiazole-4-sulfonylamino)-4-chlorobenzoic acid methyl ester (2.0 g, 5.2 mmol) in THF (12 mL) at rt was added LiOH (2 M in water, 10 mL). The resulting orange mixture was stirred overnight at rt then poured into 0.5 M HCl (150 mL) causing precipitation of the desired benzoic acid. After stirring the mixture several minutes to complete precipitation, the product was collected by suction filtration and air-dried to afford the acid as a tan solid (1.87 g, 97%). MS (ESI−): mass calcd. for C13H8ClN3O4S2, 369.8; m/z found, 368 [M−H]−. 1H NMR (400 MHz, CDCl3): 11.22 (br s, 1H), 8.43 (dd, J=7.2, 1.0, 1H), 8.26 (dd, J=8.8, 1.0, 1H), 7.90 (d, J=8.8, 1H), 7.80 (d, J=2.0, 1H), 7.75 (dd, J=8.8, 7.2, 1H), 6.99 (dd, J=8.8, 2.0, 1H). Anal. calcd. for C13H8ClN3O4S2: C, 42.22; H, 2.18; N, 11.36. Found: C, 41.92; H, 2.50; N, 11.38.
Workup
- customprecipitation of the desired benzoic acid
- stirringAfter stirring the mixture several minutes
- customprecipitation
- filtrationthe product was collected by suction filtration
- customair-dried
Sources & evidence
- ORD record
- ord-783ce8d4d2a24485addc2ba6356c1d48
- Source dataset
- uspto-grants-2010_12
- Patent number
- US07855292B2
Reaction notes
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