Hydrochloric Acid → 3-Acetyl-2,5-dihydro-4-hydroxy-5-methyl-1,2-thiazino[5,6-b]indole-1,1-dioxide

HRID 2164113Notes

Reaction equation

HRID 2164113 reaction equation
[CH2:1]([N:5]1[C:17](=[O:18])[C:8]2[N:9]([CH3:16])[C:10]3[CH:11]=[CH:12][CH:13]=[CH:14][C:15]=3[C:7]=2[S:6]1(=[O:20])=[O:19])[C:2]([CH3:4])=[O:3].Cl>C[O-].[Na+]>[C:2]([C:1]1[NH:5][S:6](=[O:20])(=[O:19])[C:7]2[C:15]3[CH:14]=[CH:13][CH:12]=[CH:11][C:10]=3[N:9]([CH3:16])[C:8]=2[C:17]=1[OH:18])(=[O:3])[CH3:4]

Participants

4

Reactant 2

HCID 313Hydrochloric AcidHCID 227500152-acetonyl-4-methyl-2H-isothiazolo [4,5-b]-indole-3(4H)-one-1,1-dioxide

Product 1

HCID 227500043-Acetyl-2,5-dihydro-4-hydroxy-5-methyl-1,2-thiazino[5,6-b]indole-1,1-dioxideYield 64.4%

Reagents, catalysts & solvents 1

HCID 10942334Sodium MethoxideSolvent

Procedure

10 gm (34 millimols) of 2-acetonyl-4-methyl-2H-isothiazolo [4,5-b]-indole-3(4H)-one-1,1-dioxide were added to a methanolic sodium methylate solution [1.6 gm of sodium (0.107 gm-atoms) in 60 ml of anhydrous methanol]. After half an hour of stirring at room temperature, the mixture was heated for 45 minutes on an oil bath at 60° C. Subsequently, the reaction mixture was cooled on an ice bath and acidified with 1 N hydrochloric acid to a pH of 3-4. The precipitate formed thereby was filtered off, washed with ice water, dried and recrystallized from ethylene chloride, yielding 6.4 gm (64% of theory) of 3-acetyl-2,5-dihydro-4-hydroxy-5-methyl-1,2-thiazino[5,6-b ]-indole-1,1-dioxide. M.p.: 210°-211° C.;

Workup

  1. temperaturethe mixture was heated for 45 minutes on an oil bath at 60° C
  2. temperatureSubsequently, the reaction mixture was cooled on an ice bath
  3. customThe precipitate formed
  4. filtrationthereby was filtered off
  5. washwashed with ice water
  6. customdried
  7. customrecrystallized from ethylene chloride

Sources & evidence

ORD record
ord-359a71b7d8e04434a8b1e5ab04ea8909
Source dataset
uspto-grants-1979_01
Patent number
US04137313

Reaction notes

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