Sodium Dithionite → 4-bromo-2,7-dimethoxy-3-hydroxy-10H-phenothiazine

HRID 979309Notes

Reaction equation

HRID 979309 reaction equation
[Br:1][C:2]1[C:3](=[O:20])[C:4]([O:18][CH3:19])=[CH:5][C:6]2[C:15]=1[S:14][C:13]1[C:8](=[CH:9][CH:10]=[C:11]([O:16][CH3:17])[CH:12]=1)[N:7]=2.S(S([O-])=O)([O-])=O.[Na+].[Na+]>C(OCC)(=O)C.O>[Br:1][C:2]1[C:15]2[S:14][C:13]3[C:8](=[CH:9][CH:10]=[C:11]([O:16][CH3:17])[CH:12]=3)[NH:7][C:6]=2[CH:5]=[C:4]([O:18][CH3:19])[C:3]=1[OH:20]

Participants

5

Reactant 2

HCID 24489Sodium DithioniteHCID 1221824-Bromo-2,7-dimethoxy-3H-phenothiazin-3-one

Product 1

HCID 138537384-bromo-2,7-dimethoxy-3-hydroxy-10H-phenothiazineYield 129.3%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 8857Ethyl AcetateSolvent

Procedure

To a suspension of 4-bromo-2,7-dimethoxy-3H-phenothiazin-3-one (100 g) in a mixture of ethyl acetate (2 l) and water (1 l) was added sodium hydrosulfite (200 g) in one batch with mechanical stirring. The orange reaction mixture was stirred for 15 hours under a nitrogen atmosphere. The resulting white reaction mixture was filtered and the precipitate washed with water under a nitrogen atmosphere to prevent air oxidation of the compound. The title compound (130 g) was obtained as a wet material and was used as such in the next step (Step 2). An analytical sample was air dried, m.p. 185° C.

Workup

  1. filtrationThe resulting white reaction mixture was filtered
  2. washthe precipitate washed with water under a nitrogen atmosphere

Sources & evidence

ORD record
ord-910e31368f7841b597278a48f33dfee3
Source dataset
uspto-grants-1987_05
Patent number
US04667032

Reaction notes

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