Saccharin → 3,3-diphenyl-2H-1,2-benzothiazole 1,1-dioxide

HRID 2198803

Reaction equation

HRID 2198803 reaction equation
[S:1]1([C:12]2[C:7](=[CH:8][CH:9]=[CH:10][CH:11]=2)[C:5](=O)[NH:4]1)(=[O:3])=[O:2].[C:13]1([Mg]Br)[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=1>O1CCCC1>[C:13]1([C:5]2([C:7]3[CH:12]=[CH:11][CH:10]=[CH:9][CH:8]=3)[C:7]3[CH:8]=[CH:9][CH:10]=[CH:11][C:12]=3[S:1](=[O:3])(=[O:2])[NH:4]2)[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=1

Participants

4

Procedure

Various procedures have been reported for synthesizing 3-substituted-benz[d]isothiazole-1,1-dioxides and 3,3-disubstituted-2,3-dihydrobenz[d]isothiazole-1,1-dioxides from saccharin (3-oxo-2,3-dihydrobenz[d]isothiazole-1,1-dioxide) and from saccharin pseudo-chloride (3-chlorobenz[d]isothiazole-1,1-dioxide). As reported by A. Mustafa et al, J. Chem Soc., 1952, p. 1339, the treatment of saccharin pseudo-chloride with excess phenylmagnesium bromide gave the corresponding 3,3-diphenyl-2,3-dihydrobenz[d]isothiazole-1,1-dioxide in almost quantitative yield. Methyl-, ethyl-, n-propyl- and n-butylmagnesium halides were reported by these authors to react analogously. R. A. Abramovitch et al, J. Chem. Soc., Perkin Trans I, 1974(22), p. 2589, reviewed and reinvestigated the reactions of saccharins with alkyl and aryl Grignard reagents and found that either the 3-alkyl (or 3-aryl)-benz[d]isothiazole-1,1-dioxide and/or the open-chain tertiary alcohol, o-CR2OH benzenesulfonamide wherein R is alkyl (or aryl) were obtained with one exception. When saccharin was treated with an excess of phenylmagnesium bromide in boiling tetrahydrofuran, 3,3-diphenyl-2,3-dihydrobenz[d]isothiazole-1,1-dioxide was obtained as the minor product together with the open-chain tertiary alcohol.

Workup

  1. customto react analogously
  2. customwere obtained with one exception

Sources & evidence

ORD record
ord-1e937190904d449096278125331a9722
Source dataset
uspto-grants-1982_11
Patent number
US04359574

Linked notes

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