Perchloric Acid → (S)-ethyl 2-tert-butoxy-2-(2-chloro-5-methyl-7-(trifluoromethylsulfonyloxy)benzo[d]thiazol-6-yl)acetate

HRID 879347Notes

Reaction equation

HRID 879347 reaction equation
[Cl:1][C:2]1[S:3][C:4]2[C:10]([O:11][S:12]([C:15]([F:18])([F:17])[F:16])(=[O:14])=[O:13])=[C:9]([C@H:19]([OH:25])[C:20]([O:22][CH2:23][CH3:24])=[O:21])[C:8]([CH3:26])=[CH:7][C:5]=2[N:6]=1.Cl(O)(=O)(=O)=O.[C:32](O[C@@H](C1C(C)=CC2N=C(Br)SC=2C=1OS(C(F)(F)F)(=O)=O)C(OCC)=O)([CH3:35])([CH3:34])[CH3:33]>C(OC(C)(C)C)(=O)C>[C:32]([O:25][C@@H:19]([C:9]1[C:8]([CH3:26])=[CH:7][C:5]2[N:6]=[C:2]([Cl:1])[S:3][C:4]=2[C:10]=1[O:11][S:12]([C:15]([F:18])([F:16])[F:17])(=[O:14])=[O:13])[C:20]([O:22][CH2:23][CH3:24])=[O:21])([CH3:35])([CH3:34])[CH3:33]

Participants

5

Reactant 3

HCID 24247Perchloric AcidHCID 86699785(S)-ethyl 2-(2-bromo-5-methyl-7-(trifluoromethylsulfonyloxy)benzo[d]thiazol-6-yl)-2-tert-butoxyacetateHCID 86700144(S)-ethyl 2-(2-chloro-5-methyl-7-(trifluoromethylsulfonyloxy)benzo[d]thiazol-6-yl)-2-hydroxyacetate

Product 1

HCID 86700146(S)-ethyl 2-tert-butoxy-2-(2-chloro-5-methyl-7-(trifluoromethylsulfonyloxy)benzo[d]thiazol-6-yl)acetate

Reagents, catalysts & solvents 1

HCID 10908tert-Butyl acetateSolvent

Procedure

To a solution of (S)-ethyl 2-(2-chloro-5-methyl-7-(trifluoromethylsulfonyloxy)benzo[d]thiazol-6-yl)-2-hydroxyacetate (0.5691 g, 1.31 mmol) in tert-butyl acetate (65 mL) was added 70% perchloric acid (65 μL, 1.57 mmol). Reaction mixture was stirred for 1.5 h and quenched with solid sodium bicarbonate. Saturated sodium bicarbonate solution was carefully added until basic and mixture was extracted with ethyl acetate. The organic layer was washed with saturated sodium bicarbonate solution, brine, dried (MgSO4), filtered, concentrated and purified by CombiFlash (0 to 15% EtOAc/Hex) to give product contaminated with (S)-ethyl 2-tert-butoxy-2-(2-bromo-5-methyl-7-(trifluoromethylsulfonyloxy)benzo[d]thiazol-6-yl)acetate. 1H NMR (400 MHz, CDCl3): δ 7.78 (s, 1H), 5.59 (s, 1H), 4.4-4.1 (m, 2H), 2.55 (s, 3H), 1.20 (s, 9H), 1.16 (t, J=7.2 Hz, 3H).

Workup

  1. customReaction mixture
  2. customquenched with solid sodium bicarbonate
  3. additionSaturated sodium bicarbonate solution was carefully added until basic and mixture
  4. extractionwas extracted with ethyl acetate
  5. washThe organic layer was washed with saturated sodium bicarbonate solution, brine
  6. dry with materialdried (MgSO4)
  7. filtrationfiltered
  8. concentrationconcentrated
  9. custompurified by CombiFlash (0 to 15% EtOAc/Hex)
  10. customto give product

Sources & evidence

ORD record
ord-468c3529563e4adf986630908bf4a1ed
Source dataset
uspto-grants-2015_03
Patent number
US08987250B2

Reaction notes

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