Sulfuric Acid → 6-Amino-3-chloro-2-(4-methyl-piperazine-1-sulfonyl)-phenol

HRID 1528219Notes

Reaction equation

HRID 1528219 reaction equation
S(=O)(=O)(O)O.C(C1[O:11][C:12]2[C:18]([S:19]([N:22]3[CH2:27][CH2:26][N:25]([CH3:28])[CH2:24][CH2:23]3)(=[O:21])=[O:20])=[C:17]([Cl:29])[CH:16]=[CH:15][C:13]=2[N:14]=1)(C)(C)C>O.O1CCOCC1>[NH2:14][C:13]1[C:12]([OH:11])=[C:18]([S:19]([N:22]2[CH2:27][CH2:26][N:25]([CH3:28])[CH2:24][CH2:23]2)(=[O:21])=[O:20])[C:17]([Cl:29])=[CH:16][CH:15]=1

Participants

5

Reactant 2

HCID 1118Sulfuric AcidHCID 234478362-tert-Butyl-6-chloro-7-(4-methylpiperazine-1-sulfonyl)-benzooxazole

Product 1

HCID 234478576-Amino-3-chloro-2-(4-methyl-piperazine-1-sulfonyl)-phenolYield 68%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 312751,4-DioxaneSolvent

Procedure

4.27 ml (0.08 mol; 1.20 V) of sulfuric acid diluted in 4.3 ml of water were added dropwise to 3.56 g of 2-tert-butyl-6-chloro-7-(4-methylpiperazine-1-sulfonyl)benzooxazole (0.01 mol; 1.0 eq) in solution in 15 ml of 1,4-dioxane. The reaction medium was refluxed for six and a half hours. The reaction medium was concentrated and 1 N sodium hydroxide was added (to pH 7). The solution was extracted with dichloromethane. The organic phases were combined, dried over magnesium sulfate, filtered and evaporated. The residue obtained was chromatographed on silica gel, eluent 95/5 ethyl acetate/dichloromethane. 2.0 g of 6-amino-3-chloro-2-(4-methylpiperazine-1-sulfonyl)phenol were obtained in the form of a thick brown oil. Yield=68%.

Workup

  1. temperatureThe reaction medium was refluxed for six and a half hours
  2. concentrationThe reaction medium was concentrated
  3. addition1 N sodium hydroxide was added (to pH 7)
  4. extractionThe solution was extracted with dichloromethane
  5. dry with materialdried over magnesium sulfate
  6. filtrationfiltered
  7. customevaporated
  8. customThe residue obtained
  9. customwas chromatographed on silica gel, eluent 95/5 ethyl acetate/dichloromethane

Sources & evidence

ORD record
ord-a9f7ecd529774eb7b2fa463da7425de6
Source dataset
uspto-grants-2015_07
Patent number
US09090596B2

Reaction notes

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