Sodium Hydroxide → 4-Methoxy-1H-1lambda~6~,2-benzothiazole-1,1,3(2H)-trione

HRID 1995386Notes

Reaction equation

HRID 1995386 reaction equation
N[C:2]1[C:6]2[C:7]([O:11][CH3:12])=[CH:8][CH:9]=[CH:10][C:5]=2[S:4](=[O:14])(=[O:13])[N:3]=1.[OH-:15].[Na+]>>[CH3:12][O:11][C:7]1[C:6]2[C:2](=[O:15])[NH:3][S:4](=[O:14])(=[O:13])[C:5]=2[CH:10]=[CH:9][CH:8]=1

Participants

3

Reactant 2

HCID 14798Sodium HydroxideHCID 155671643-Amino-4-methoxy-1,2-benzoisothiazole-1,1-dioxide

Product 1

HCID 149840514-Methoxy-1H-1lambda~6~,2-benzothiazole-1,1,3(2H)-trione

Procedure

2.5 gm (11.8 mmols) of 3-amino-4-methoxy-1,2-benzoisothiazole-1,1-dioxide were reacted with sodium hydroxide analogous to Example 4. The reaction mixture was acidified, whereby 4-methoxy-1,2-benzoisothiazol-3(2H)-one-1,1-dioxide was obtained, which was subsequently heated at 200°-205° C. with 20 gm of pyridine hydrochloride. After cooling, the reaction mixture was extracted several times with boiling benzene, the residue was dissolved in water, and the aqueous solution was again extracted with boiling benzene. The combined benzene phases were dried and evaporated in vacuo. The residue was recrystallized from water, yielding 1.35 gm (57.5% of theory) of 4-hydroxy-1,2-benzoisothiazol-3(2H)-one-1,1-dioxide.

Sources & evidence

ORD record
ord-2faacf51cc7f4b04b8102f82606b8dc4
Source dataset
uspto-grants-1983_09
Patent number
US04404230

Reaction notes

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