Potassium Acetate → (7-Oxo-1-phenyl-1,7-dihydropyrazolo[1,5-a]pyrimidin-5-yl)methyl acetate

HRID 1154535Notes

Reaction equation

HRID 1154535 reaction equation
Cl[CH2:2][C:3]1[N:4]=[C:5]2[CH:12]=[CH:11][N:10]([C:13]3[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=3)[N:6]2[C:7](=[O:9])[CH:8]=1.[C:19]([O-:22])(=[O:21])[CH3:20].[K+]>CN(C)C=O>[C:19]([O:22][CH2:2][C:3]1[N:4]=[C:5]2[CH:12]=[CH:11][N:10]([C:13]3[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=3)[N:6]2[C:7](=[O:9])[CH:8]=1)(=[O:21])[CH3:20]

Participants

4

Reactant 2

HCID 517044Potassium AcetateHCID 132320785-(Chloromethyl)-1-phenylpyrazolo[1,5-a]pyrimidin-7(1H)-one

Product 1

HCID 13232097(7-Oxo-1-phenyl-1,7-dihydropyrazolo[1,5-a]pyrimidin-5-yl)methyl acetate

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

5-chloromethyl-1-phenyl-1H,7H-pyrazolo[1,5-a]pyrimidine-7-one (5.2 g), prepared according to Example 1, was dissolved in dimethylformamide (30 ml) and reacted with anhydrous potassium acetate (4 g) under stirring at room temperature for 20 hours. After dilution with ice water the precipitate was filtered and washed with water to give 5-acetoxymethyl-1-phenyl-1H,7H-pyrazolo[1,5-a]pyrimidine-7-one, m.p. 172°-175° C., (4.9 g) which was hydrolized by treatment with 8% HCl (50 ml) under stirring at 90° C. for 30 minutes. The reaction mixture was neutralized with 35% NaOH and the precipitate was filtered and washed with water to give 5-hydroxymethyl-1-phenyl-1H,7H-pyrazolo[1,5-a]pyrimidine-7-one, m.p. 241°-242° C., (4.1 g), which was reacted with dicyclohexylcarbodiimide (8 g) in benzene (60 ml) and dimethylsulphoxide (15 ml) in the presence of trifluoroacetic acid (0.6 ml) and pyridine (1 ml) under stirring at room temperature for 20 hours. After treatment with oxalic acid bihydrate (1.8 g) at room temperature, the precipitate of dicyclohexylurea was filtered off and the organic solution was evaporated in vacuo to dryness: the residue was purified over a SiO2 column using chloroform: ethyl acetate=95:5 as eluent. The 7-formyl-1-phenyl-1H,7H-pyrazolo[1,5-a]pyrimidine-7-one so obtained (2.5 g) was reacted with the ylide obtained by treatment of (3-pyridyl)-methyl-triphenylphosphonium chloride (4.2 g) with potassium tert-butoxide (1.25 g) in dimethylsulphoxide (20 ml) at room temperature for 30 minutes. After dilution with ice water the precipitate was filtered and washed with water: crystallization from isopropyl alcohol gave 2.05 g of 1-phenyl-5-trans-[2-(3-pyridyl)ethenyl]-1H,7H-pyrazolo[1,5-a]pyrimidine-7-one, m.p. 221°-224° C.

Workup

  1. filtrationAfter dilution with ice water the precipitate was filtered
  2. washwashed with water

Sources & evidence

ORD record
ord-9cbf763db3154e56b04436edaa953ddf
Source dataset
uspto-grants-1984_12
Patent number
US04490376

Reaction notes

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