Methyl iodide → 4-Bromo-2,3,7-trimethoxy-10H-phenothiazine

HRID 979092Notes

Reaction equation

HRID 979092 reaction equation
[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].CI.[C:23](=O)([O-])[O-].[K+].[K+]>CN(C=O)C.O.C(OCC)(=O)C>[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[O:20][CH3:23]

Participants

7

Reactant 3

HCID 6328Methyl iodideHCID 11430Potassium Carbonate2×HCID 138537384-bromo-2,7-dimethoxy-3-hydroxy-10H-phenothiazine

Product 1

HCID 138820384-Bromo-2,3,7-trimethoxy-10H-phenothiazineYield 36.7%

Reagents, catalysts & solvents 3

HCID 962WaterSolventHCID 6228DimethylformamideSolventHCID 8857Ethyl AcetateSolvent

Procedure

To a solution of 4-bromo-2,7-dimethoxy-3-hydroxy-10H-phenothiazine (3.54 g) and methyliodide (2.5 ml) in DMF (20 ml) there was added pulverized potassium carbonate (1.3 g). The reaction mixture was stirred at room temperature. After 15 minutes, another addition of potassium carbonate (1 gram) was made, followed by two other such additions at 15-minute intervals. The final mixture was stirred for a further 15 minutes, then it was diluted with water (100 ml) and ethyl acetate (100 ml). The organic layer was washed twice with water, dried and evaporated down to a solid residue. Crystallization from acetone followed by column chromatography on silica gel eluting with 1:19 ethyl acetate-dichloromethane afforded the pure title compound (1.27 g). m.p. 223°-225° C.

Workup

  1. waitfollowed by two other such additions at 15-minute
  2. washThe organic layer was washed twice with water
  3. customdried
  4. customevaporated down to a solid residue
  5. customCrystallization from acetone

Sources & evidence

ORD record
ord-e805811533434951985b0b30723bfce5
Source dataset
uspto-grants-1987_05
Patent number
US04666907

Reaction notes

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