Acetic Acid → 4H-1,4-Benzothiazin-3-one

HRID 1377689Notes

Reaction equation

HRID 1377689 reaction equation
[NH2:1][C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][C:3]=1[S:8][CH2:9][C:10]([O:12]CC)=O.C(OC(N1CCC(=O)CC1)=O)(C)(C)C.C(O)(=O)C.C(O[BH-](OC(=O)C)OC(=O)C)(=O)C.[Na+].C(=O)(O)[O-].[Na+]>ClC(Cl)C>[S:8]1[C:3]2[CH:4]=[CH:5][CH:6]=[CH:7][C:2]=2[NH:1][C:10](=[O:12])[CH2:9]1

Participants

7

Reactant 5

HCID 176Acetic AcidHCID 516892Sodium BicarbonateHCID 735900tert-Butyl 4-oxopiperidine-1-carboxylateHCID 2736362Ethyl (2-aminophenyl)mercaptoacetateHCID 5049666Sodium triacetoxyborohydride

Product 1

HCID 213964H-1,4-Benzothiazin-3-oneYield 39.4%

Reagents, catalysts & solvents 1

HCID 63651,1-DichloroethaneSolvent

Procedure

Ethyl (2-aminophenyl)mercaptoacetate (322 mg, 1.52 mmole), N-tert-butyloxycarbonylpiperidin-4-one (456 mg, 2.29 mmole), acetic acid (478 ml, 8.36 mmole), and sodium triacetoxyborohydride (966 mg, 4.56 mmole) were combined in 10 ml of dichloroethane at room temperature, protected from moisture and stirred overnight. Saturated sodium bicarbonate solution was added and the reaction mixture was extracted with ethyl acetate. The combined extracts were washed with sodium bicarbonate solution and brine, then dried and concentrated. The crude product was chromatographed on silica gel (ethyl acetate-hexane elution, 1:3 v/v) to give 210 mg of the title compound along with 99 mg of 2H-1,4-benzothiazin-3(4H)-one.

Workup

  1. extractionthe reaction mixture was extracted with ethyl acetate
  2. washThe combined extracts were washed with sodium bicarbonate solution and brine
  3. customdried
  4. concentrationconcentrated
  5. customThe crude product was chromatographed on silica gel (ethyl acetate-hexane elution, 1:3 v/v)

Sources & evidence

ORD record
ord-c07ec6b7ce2643b79ed519549334feea
Source dataset
uspto-grants-1997_09
Patent number
US05665719

Reaction notes

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