Potassium Hydroxide → tert-Butyl[3-bromo-6-methyl-2-(methylthio)pyrazolo[5,1-b][1,3]thiazol-7-yl]carbamate

HRID 41257Notes

Reaction equation

HRID 41257 reaction equation
[C:1]([O:5][C:6]([NH:8][C:9]1[C:10]([CH3:22])=[N:11][N:12]2[C:16](C(O)=O)=[C:15]([S:20][CH3:21])[S:14][C:13]=12)=[O:7])([CH3:4])([CH3:3])[CH3:2].[OH-].[K+].[Br:25]Br>C(=O)([O-])[O-].[Ag+2].C(Cl)(Cl)Cl>[C:1]([O:5][C:6](=[O:7])[NH:8][C:9]1[C:10]([CH3:22])=[N:11][N:12]2[C:16]([Br:25])=[C:15]([S:20][CH3:21])[S:14][C:13]=12)([CH3:4])([CH3:3])[CH3:2]

Participants

6

Reactant 3

HCID 14797Potassium HydroxideHCID 24408BromineHCID 58223446HCID 58223446, compound

Product 1

HCID 58223503tert-Butyl[3-bromo-6-methyl-2-(methylthio)pyrazolo[5,1-b][1,3]thiazol-7-yl]carbamateYield 47.2%

Reagents, catalysts & solvents 2

HCID 178418647HCID 178418647, compoundCatalystHCID 6212ChloroformSolvent

Procedure

To an aqueous solution (10 mL) of 7-[(tert-butoxycarbonyl)amino]-6-methyl-2-(methylthio)pyrazolo[5,1-b][1,3]thiazole-3-carboxylic acid (180 mg, 0.53 mmol), were added potassium hydroxide (34.7 mg, 0.53 mmol) and silver carbonate (93.6 mg, 0.55 mmol), and the mixture was stirred at room temperature for 1.5 hours. The solid was filtered, washed with water, and then dried. To a mixture of the obtained solid and carbon tetrachloride (3.6 mL) was added bromine (29.6 μL, 0.58 mmol), and the mixture was stirred at 75° C. for five hours. To the reaction mixture was added chloroform, and the insoluble matters were filtered off, and then the solvent was distilled off under reduced pressure. The residue was purified by medium pressure silica gel column chromatography (n-heptane/ethyl acetate: 33% then 66%) to obtain 94.0 mg (0.25 mmol) of the title compound.

Workup

  1. filtrationThe solid was filtered
  2. washwashed with water
  3. customdried
  4. additionTo a mixture of the obtained solid and carbon tetrachloride (3.6 mL)
  5. stirringthe mixture was stirred at 75° C. for five hours
  6. filtrationthe insoluble matters were filtered off
  7. distillationthe solvent was distilled off under reduced pressure
  8. customThe residue was purified by medium pressure silica gel column chromatography (n-heptane/ethyl acetate

Sources & evidence

ORD record
ord-a3b224a81f434f3295bd0f71187bc11b
Source dataset
uspto-grants-2013_09
Patent number
US08530504B2

Reaction notes

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