Ammonia → 2-Amino-3,4-dihydro-3-oxo-2H-1,4-benzothiazine

HRID 1591451Notes

Reaction equation

HRID 1591451 reaction equation
[NH3:1].Cl[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>C(Cl)Cl>[NH2:1][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 222AmmoniaHCID 122185992H-1,4-Benzothiazin-3(4H)-one, 2-chloro-

Product 1

HCID 107974522-Amino-3,4-dihydro-3-oxo-2H-1,4-benzothiazineYield 41%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

Anhydrous ammonia gas was bubbled for one hour through a suspension of 500 mg (2.5 mmol) of 2-chloro-3,4-dihydro-3-oxo-2H-1,4-benzothiazine (prepared by the method of Worley, et al; J. Org. Chem., 40, 1731-1734 (1975)) in 5 mL of methylene chloride. The mixture was filtered through Celite and the filtrate evaporated under vacuum. The residue was triturated with 20 mL of chloroform, filtered and the filtrate evaporated under vacuum. Purification by flash chromatography on silica, eluting with ethyl acetate, afforded 185 mg (1.0 mmol, 41%) of the product. 1H NMR (200 MHz, CDCl3): 2.00 (br s,2H), 4.68 (br s,1H), 6.9-7.4 (m,4H), 9.05 (br s,1H). FAB-MS: calculated for C8H8N2OS 180; found 181 (M+H,54%).

Workup

  1. customprepared by the method of Worley, et al
  2. filtrationThe mixture was filtered through Celite
  3. customthe filtrate evaporated under vacuum
  4. customThe residue was triturated with 20 mL of chloroform
  5. filtrationfiltered
  6. customthe filtrate evaporated under vacuum
  7. customPurification by flash chromatography on silica
  8. washeluting with ethyl acetate

Sources & evidence

ORD record
ord-f34e9671558b45beab8c900bbd8b7e62
Source dataset
uspto-grants-1993_04
Patent number
US05206235

Reaction notes

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