tert-Butanol → Tert-butyl (6-methoxypyrazolo[5,1-b][1,3]thiazol-7-yl)carbamate

HRID 1971783Notes

Reaction equation

HRID 1971783 reaction equation
[CH3:1][O:2][C:3]1[C:10](C(O)=O)=[C:6]2[S:7][CH:8]=[CH:9][N:5]2[N:4]=1.C([N:16]([CH2:19]C)CC)C.C1(P(N=[N+]=[N-])(C2C=CC=CC=2)=[O:28])C=CC=CC=1.[C:38]([OH:42])([CH3:41])([CH3:40])[CH3:39]>O1CCOCC1>[CH3:1][O:2][C:3]1[C:10]([NH:16][C:19](=[O:28])[O:42][C:38]([CH3:41])([CH3:40])[CH3:39])=[C:6]2[S:7][CH:8]=[CH:9][N:5]2[N:4]=1

Participants

6

Reactant 4

HCID 6386tert-ButanolHCID 8471Triethylamine2×HCID 199401P,P-Diphenylphosphinic azideHCID 670951146-Methoxypyrazolo[5,1-b]thiazole-7-carboxylic acid

Product 1

HCID 57912437Tert-butyl (6-methoxypyrazolo[5,1-b][1,3]thiazol-7-yl)carbamateYield 35.4%

Reagents, catalysts & solvents 1

HCID 312751,4-DioxaneSolvent

Procedure

To a mixture of 6-methoxypyrazolo[5,1-b]thiazole-7-carboxylic acid (300 mg, 1.51 mmol) and 1,4-dioxane (4 mL) were added triethylamine (0.215 mL, 1.54 mmol) and diphenylphosphoryl azide (0.325 mL, 1.51 mmol) while stirring at room temperature, and the mixture was stirred and heated to reflux for 3 hour. After returning the mixture to room temperature, triethylamine (0.631 mL, 4.53 mmol) and tert-butanol (0.289 mL, 3.02 mmol) were added and the mixture was stirred and heated to reflux for 3 hour. After returning the mixture to room temperature, the solvent in the mixture was distilled off under reduced pressure and the residue was purified by silica gel column chromatography (mixture of n-heptane and ethyl acetate: n-heptane/ethyl acetate=1/4) to obtain the title compound (144 mg, 0.535 mmol).

Workup

  1. stirringthe mixture was stirred
  2. temperatureheated
  3. temperatureto reflux for 3 hour
  4. customto room temperature
  5. stirringthe mixture was stirred
  6. temperatureheated
  7. temperatureto reflux for 3 hour
  8. customto room temperature
  9. distillationthe solvent in the mixture was distilled off under reduced pressure
  10. customthe residue was purified by silica gel column chromatography (mixture of n-heptane and ethyl acetate: n-heptane/ethyl acetate=1/4)

Sources & evidence

ORD record
ord-be7a4a4dee7c42d5bb5b1889f6636f31
Source dataset
uspto-grants-2013_04
Patent number
US08431603B2

Reaction notes

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