Triethylamine → 6-(3-Nitrophenyl)-7-pyridin-4-yl-pyrazolo[5,1-b]thiazole

HRID 38092Notes

Reaction equation

HRID 38092 reaction equation
O[CH:2]1[CH2:6][S:5][C:4]2=[C:7]([C:19]3[CH:24]=[CH:23][N:22]=[CH:21][CH:20]=3)[C:8]([C:10]3[CH:15]=[CH:14][CH:13]=[C:12]([N+:16]([O-:18])=[O:17])[CH:11]=3)=[N:9][N:3]12.FC(F)(F)C(OC(=O)C(F)(F)F)=O.C(N(CC)CC)C>C(COC)OC.C(OCC)(=O)C>[N+:16]([C:12]1[CH:11]=[C:10]([C:8]2[C:7]([C:19]3[CH:24]=[CH:23][N:22]=[CH:21][CH:20]=3)=[C:4]3[S:5][CH:6]=[CH:2][N:3]3[N:9]=2)[CH:15]=[CH:14][CH:13]=1)([O-:18])=[O:17]

Participants

6

Reactant 3

HCID 8471TriethylamineHCID 9845Trifluoroacetic anhydrideHCID 674426243-Hydroxy-6-(3-nitrophenyl)-7-pyridin-4-yl-2,3-dihydro-pyrazolo[5,1-b]thiazole

Product 1

HCID 674230846-(3-Nitrophenyl)-7-pyridin-4-yl-pyrazolo[5,1-b]thiazoleYield 44%

Reagents, catalysts & solvents 2

HCID 80711,2-DimethoxyethaneSolventHCID 8857Ethyl AcetateSolvent

Procedure

3-Hydroxy-6-(3-nitrophenyl)-7-pyridin-4-yl-2,3-dihydro-pyrazolo[5,1-b]thiazole (1 g, 2.938 mmol) was dissolved in dimethoxyethane (15 mL) under nitrogen atmosphere. Trifluoroacetic anhydride (0.8 mL, 5.664 mmol, 2 eq) and triethylamine (0.41 mL, 2.938 mmol, 1 eq) were added and the mixture was stirred at room temperature for 3 days. The solution was then diluted with ethyl acetate and washed with saturated aqueous NaHCO3 and brine, dried and evaporated to dryness. The crude product was purified by chromatography on silica gel (eluant: DCM/MeOH 97:3) to give 417 mg (44%) of 6-(3-nitrophenyl)-7-pyridin-4-yl-pyrazolo[5,1-b]thiazole as white solid.

Workup

  1. washwashed with saturated aqueous NaHCO3 and brine
  2. customdried
  3. customevaporated to dryness
  4. customThe crude product was purified by chromatography on silica gel (eluant: DCM/MeOH 97:3)

Sources & evidence

ORD record
ord-e1c0c9c50a1b408cb31653d5f47a20fb
Source dataset
uspto-grants-2013_09
Patent number
US08524707B2

Reaction notes

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