Methyl iodide → 3-methylthio-2H-1,4-benzothiazine

HRID 27743Notes

Reaction equation

HRID 27743 reaction equation
[H-].[Na+].[S:3]1[C:8]2[CH:9]=[CH:10][CH:11]=[CH:12][C:7]=2[NH:6][C:5](=[S:13])[CH2:4]1.I[CH3:15]>O1CCCC1>[CH3:15][S:13][C:5]1[CH2:4][S:3][C:8]2[CH:9]=[CH:10][CH:11]=[CH:12][C:7]=2[N:6]=1

Participants

5

Reactant 3

HCID 6328Methyl iodideHCID 24758Sodium hydrideHCID 7739812H-1,4-Benzothiazine-3(4H)-thione

Product 1

HCID 125454293-methylthio-2H-1,4-benzothiazine

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Procedure

To 17 parts of sodium hydride in 1500 parts of tetrahydrofuran at room temperature under nitrogen is added, portionwise with stirring during approximately 15 minutes, 90 parts of 2H-1,4-benzothiazine-3(4H)-thione [J. Med. Chem. 12, 290 (1969)]. After the addition is complete, stirring under nitrogen is continued for 10 minutes, whereupon a solution of 85 parts of iodomethane in 70 parts of tetrahydrofuran is rapidly stirred in and stirring continued thereafter for a still further 15 minutes. Removal of solvent by vacuum distillation under nitrogen affords 3-methylthio-2H-1,4-benzothiazine as the residue. Since the product is subject to spontaneous hydrolytic decomposition, it is not usually isolated for the purposes of this invention but instead is employed as the solution in tetrahydrofuran preparable via the foregoing procedure.

Workup

  1. additionAfter the addition
  2. stirringstirring under nitrogen
  3. stirringis rapidly stirred in and
  4. stirringstirring
  5. waitfor a still further 15 minutes
  6. customRemoval of solvent
  7. distillationby vacuum distillation under nitrogen

Sources & evidence

ORD record
ord-177eee20f9c144d989d36dc5c1aa107e
Source dataset
uspto-grants-1980_09
Patent number
US04223136

Reaction notes

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