Hydrochloric Acid → 2-(4-Fluorophenyl)-3-(pyridin-4-yl)pyrazolo[1,5-a]pyrimidine

HRID 54938

Reaction equation

HRID 54938 reaction equation
[NH2:1][C:2]1[NH:6][N:5]=[C:4]([C:7]2[CH:12]=[CH:11][C:10]([F:13])=[CH:9][CH:8]=2)[C:3]=1[C:14]1[CH:19]=[CH:18][N:17]=[CH:16][CH:15]=1.Cl.CO[CH:23](OC)[CH2:24][CH:25](OC)OC.C(=O)(O)[O-].[Na+]>C(O)C.[Cl-].[Zn+2].[Cl-]>[F:13][C:10]1[CH:11]=[CH:12][C:7]([C:4]2[C:3]([C:14]3[CH:19]=[CH:18][N:17]=[CH:16][CH:15]=3)=[C:2]3[N:1]=[CH:23][CH:24]=[CH:25][N:6]3[N:5]=2)=[CH:8][CH:9]=1

Participants

7

Reactant 4

HCID 313Hydrochloric AcidHCID 66019TetramethoxypropaneHCID 516892Sodium BicarbonateHCID 178509109HCID 178509109, compound

Product 1

HCID 199572802-(4-Fluorophenyl)-3-(pyridin-4-yl)pyrazolo[1,5-a]pyrimidineYield 87.6%

Reagents, catalysts & solvents 2

HCID 3007855ZincchlorideCatalystHCID 702EthanolSolvent

Procedure

To a solution of 5-amino-3-(4-fluorophenyl)-4-(pyridin-4-yl)pyrazole (102 mg) in ethanol (3 ml) were added concentrated hydrochloric acid (50 μl ), zinc chloride (27 mg) and 1,1,3,3-tetramethoxypropane (72 mg) in that order. The mixture was refluxed for one hour, cooled, and poured into an aqueous saturated sodium bicarbonate solution. The separated oil was extracted with dichloromethane. The extract was washed with brine, dried and concentrated in vacuo. The residue was crystallized from a mixture of ethyl acetate and diethyl ether to yield 2-(4-fluorophenyl)-3-(pyridin-4-yl)pyrazolo[1,5-a]pyrimidine (102 mg).

Workup

  1. temperatureThe mixture was refluxed for one hour
  2. temperaturecooled
  3. extractionThe separated oil was extracted with dichloromethane
  4. washThe extract was washed with brine
  5. customdried
  6. concentrationconcentrated in vacuo
  7. customThe residue was crystallized from a mixture of ethyl acetate and diethyl ether

Sources & evidence

ORD record
ord-ae2a07aaacbc4495a74969ee0c2cc6ff
Source dataset
uspto-grants-1997_04
Patent number
US05624931

Linked notes

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