Thionyl Chloride → 2-(Chloromethyl)-2H-1,4-benzothiazin-3(4H)-one

HRID 235639Notes

Reaction equation

HRID 235639 reaction equation
O[CH2:2][CH:3]1[C:8](=[O:9])[NH:7][C:6]2[CH:10]=[CH:11][CH:12]=[CH:13][C:5]=2[S:4]1.S(Cl)([Cl:16])=O>C(Cl)(Cl)Cl>[Cl:16][CH2:2][CH:3]1[C:8](=[O:9])[NH:7][C:6]2[CH:10]=[CH:11][CH:12]=[CH:13][C:5]=2[S:4]1

Participants

4

Reactant 2

HCID 24386Thionyl ChlorideHCID 3300302HCID 3300302, compound

Product 1

HCID 137846252-(Chloromethyl)-2H-1,4-benzothiazin-3(4H)-oneYield 58.7%

Reagents, catalysts & solvents 1

HCID 6212ChloroformSolvent

Procedure

To a solution of 1.0 g of 2-hydroxymethyl-2H-1,4-benzothiazin-3(4H)-one in 20 ml of chloroform was added 0.9 ml of thionyl chloride, and the mixture was heated for 2 hours under reflux. The mixture was concentrated under reduced pressure and the residue was extracted with ether. The extract was washed with water, dried (MgSO4), and concentrated. The crude product was subjected to a column chromatography on silica-gel (40 g). From the eluate with hexane-ethyl acetate (4:1, v/v) was obtained 640 mg (58.7%) of 2-chloromethyl-2H-1,4-benzothiazin-3(4H)-one as crystals. Recrystallization from ethyl acetate and n-hexane gave needles, m.p. 152°-153° C.

Workup

  1. temperaturethe mixture was heated for 2 hours
  2. temperatureunder reflux
  3. concentrationThe mixture was concentrated under reduced pressure
  4. extractionthe residue was extracted with ether
  5. washThe extract was washed with water
  6. dry with materialdried (MgSO4)
  7. concentrationconcentrated

Sources & evidence

ORD record
ord-ed48c1c46f6f4ef5a71cc83f13a17e44
Source dataset
uspto-grants-1987_02
Patent number
US04640916

Reaction notes

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