Ethyl Acetate → Trifluoro-methanesulfonic acid 6-methyl-8-nitro-5-oxo-2,3-dihydro-5H-thiazolo[3,2-a]pyridin-7-yl ester

HRID 1259417Notes

Reaction equation

HRID 1259417 reaction equation
S([O:8][S:9]([C:12]([F:15])([F:14])[F:13])(=[O:11])=[O:10])(C(F)(F)F)(=O)=O.O[C:17]1[C:18]([N+:28]([O-:30])=[O:29])=[C:19]2[S:27][CH2:26][CH2:25][N:20]2[C:21](=[O:24])[C:22]=1[CH3:23].C(OC(=O)C)C>C(Cl)Cl.CCCCCC>[CH3:23][C:22]1[C:21](=[O:24])[N:20]2[CH2:25][CH2:26][S:27][C:19]2=[C:18]([N+:28]([O-:30])=[O:29])[C:17]=1[O:8][S:9]([C:12]([F:13])([F:14])[F:15])(=[O:10])=[O:11]

Participants

6

Reactant 3

HCID 8857Ethyl AcetateHCID 67749Trifluoromethanesulfonic anhydrideHCID 583805737-Hydroxy-6-methyl-8-nitro-2H-thiazolo[3,2-A]pyridin-5(3H)-one

Product 1

HCID 58380549Trifluoro-methanesulfonic acid 6-methyl-8-nitro-5-oxo-2,3-dihydro-5H-thiazolo[3,2-a]pyridin-7-yl esterYield 38%

Reagents, catalysts & solvents 2

HCID 6344DichloromethaneSolvent2×HCID 8058HexaneSolvent

Procedure

Triflic anhydride (3.4 g, 12.06 mmol) was added to a stirred solution of 7-hydroxy-6-methyl-8-nitro-2,3-dihydro-thiazolo[3,2-a]pyridin-5-one (2.5 g, 10.96 mmol) and TEA (2.3 mL, 16.44 mmol) in DCM (20 mL) at −70° C. The resulting mixture was stirred at −70° C. to −50° C. for 2 hours. The reaction mixture was monitored by TLC (50% ethylacetate in hexane). The reaction mixture was diluted DCM and quenched with bicarbonate solution. The organic layer was washed with brine solution, dried over Na2SO4 and concentrated. Purification by column chromatography on silica gel (30% ethylacetate in hexane) afforded 0.9 g of the product (38% yield).

Workup

  1. customquenched with bicarbonate solution
  2. washThe organic layer was washed with brine solution
  3. dry with materialdried over Na2SO4
  4. concentrationconcentrated
  5. customPurification by column chromatography on silica gel (30% ethylacetate in hexane)

Sources & evidence

ORD record
ord-9d84932fd5a04bb3bdf775d7413bba4e
Source dataset
uspto-grants-2013_06
Patent number
US08466289B2

Reaction notes

Loading…