Sulfuric Acid → (S)-methyl 2-(2-amino-7-(4-chlorophenyl)-5-methylbenzo[d]thiazol-6-yl)-2-tert-butoxyacetate

HRID 879277Notes

Reaction equation

HRID 879277 reaction equation
[NH2:1][C:2]1[S:3][C:4]2[C:10]([C:11]3[CH:16]=[CH:15][C:14]([Cl:17])=[CH:13][CH:12]=3)=[C:9]([C@H:18]([O:22][C:23]([CH3:26])([CH3:25])[CH3:24])[C:19]([OH:21])=[O:20])[C:8]([CH3:27])=[CH:7][C:5]=2[N:6]=1.OS(O)(=O)=O.[CH3:33]COC(C)=O.C([O-])(O)=O.[Na+]>CO>[NH2:1][C:2]1[S:3][C:4]2[C:10]([C:11]3[CH:16]=[CH:15][C:14]([Cl:17])=[CH:13][CH:12]=3)=[C:9]([C@H:18]([O:22][C:23]([CH3:24])([CH3:26])[CH3:25])[C:19]([O:21][CH3:33])=[O:20])[C:8]([CH3:27])=[CH:7][C:5]=2[N:6]=1

Participants

6

Reactant 4

HCID 1118Sulfuric AcidHCID 8857Ethyl AcetateHCID 516892Sodium BicarbonateHCID 86699792(S)-2-(2-amino-7-(4-chlorophenyl)-5-methylbenzo[d]thiazol-6-yl)-2-tert-butoxyacetic acid

Product 1

HCID 86699793(S)-methyl 2-(2-amino-7-(4-chlorophenyl)-5-methylbenzo[d]thiazol-6-yl)-2-tert-butoxyacetate

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

To a solution of Preparation of (S)-2-(2-amino-7-(4-chlorophenyl)-5-methylbenzo[d]thiazol-6-yl)-2-tert-butoxyacetic acid from above in MeOH (25 mL) was added H2SO4 (200 μL). The reaction mixture was stirred at overnight. EtOAc (20 mL) and saturated NaHCO3 solution (50 mL) were added. The layers were separated, dried, filtered, and concentrated in vacuo. The crude mixture was a mixture of the desired (S)-methyl 2-(2-amino-7-(4-chlorophenyl)-5-methylbenzo[d]thiazol-6-yl)-2-tert-butoxyacetate and (S)-methyl 2-(2-amino-7-(4-chlorophenyl)-5-methylbenzo[d]thiazol-6-yl)-2-hydroxyacetate. t-Butyl acetate was added (20 mL) and perchloric acid (500 μL). The mixture was stirred at rt for 3 hr, where all (S)-methyl 2-(2-amino-7-(4-chlorophenyl)-5-methylbenzo[d]thiazol-6-yl)-2-hydroxyacetate was converted to (S)-methyl 2-(2-amino-7-(4-chlorophenyl)-5-methylbenzo[d]thiazol-6-yl)-2-tert-butoxyacetate. EtOAc (10 mL) and saturated NaHCO3 solution (50 mL) were added. The layers were separated, dried, filtered, and concentrated in vacuo. LCMS-ESI+: calc'd for C21H23ClN2O3S: 419.1 and 421.1 (M+H+); found: 419.2 and 421.2 (M+H+).

Workup

  1. customThe layers were separated
  2. customdried
  3. filtrationfiltered
  4. concentrationconcentrated in vacuo
  5. additiona mixture of the desired (S)-methyl 2-(2-amino-7-(4-chlorophenyl)-5-methylbenzo[d]thiazol-6-yl)-2-tert-butoxyacetate and (S)-methyl 2-(2-amino-7-(4-chlorophenyl)-5-methylbenzo[d]thiazol-6-yl)-2-hydroxyacetate
  6. additiont-Butyl acetate was added (20 mL) and perchloric acid (500 μL)
  7. stirringThe mixture was stirred at rt for 3 hr
  8. additionEtOAc (10 mL) and saturated NaHCO3 solution (50 mL) were added
  9. customThe layers were separated
  10. customdried
  11. filtrationfiltered
  12. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-1c293a44914548d5a30bec98eed42656
Source dataset
uspto-grants-2015_03
Patent number
US08987250B2

Reaction notes

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