Tricalcium Phosphate → 3-(3-Chlorophenyl)-pyrazolo-[1,5-a]-pyrimidine-5-carboxylic acid ethyl ester

HRID 1443840Notes

Reaction equation

HRID 1443840 reaction equation
[CH2:1]([O:3][C:4]([C:6]1[CH:11]=[CH:10][N:9]2[N:12]=[CH:13][C:14](Br)=[C:8]2[N:7]=1)=[O:5])[CH3:2].[Cl:16][C:17]1[CH:18]=[C:19](OB(O)O)[CH:20]=[CH:21][CH:22]=1.P([O-])([O-])([O-])=O.[Ca+2].P([O-])([O-])([O-])=O.[Ca+2].[Ca+2].O1CCOCC1>[Pd].C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1.C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1.C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1.C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1.O>[CH2:1]([O:3][C:4]([C:6]1[CH:11]=[CH:10][N:9]2[N:12]=[CH:13][C:14]([C:21]3[CH:20]=[CH:19][CH:18]=[C:17]([Cl:16])[CH:22]=3)=[C:8]2[N:7]=1)=[O:5])[CH3:2]

Participants

7

Reactant 4

HCID 24456Tricalcium PhosphateHCID 312751,4-DioxaneHCID 22494354m-Chlorophenylboric acidHCID 68692447Ethyl 3-bromopyrazolo[1,5-a]pyrimidine-5-carboxylate

Product 1

HCID 586288723-(3-Chlorophenyl)-pyrazolo-[1,5-a]-pyrimidine-5-carboxylic acid ethyl esterYield 89.8%

Reagents, catalysts & solvents 2

HCID 11979704Tetrakis(triphenylphosphine)palladiumCatalystHCID 962WaterSolvent

Procedure

A mixture of 3-bromo-pyrazolo-[1,5-a]-pyrimidine-5-carboxylic acid ethyl ester (18.00 g), 3-chlorophenyl boric acid (12.50 g), calcium phosphate (31.12 g), and 200 ml of dioxane was stirred under a nitrogen atmosphere, added with tetrakis(triphenylphosphine) palladium (0) (1.50 g), and heated at reflux over 3 hours. The reactant was cooled to room temperature, and thereafter poured into 150 ml of water, and extracted with 300 ml of toluene. The extract was washed with saturated saline solution, dried with magnesium sulfate, and concentrated in vacuo. The resulting residue was purified by silica gel column chromatography (ethyl acetate:toluene=8:2) to yield 3-(3-chlorophenyl)-pyrazolo-[1,5-a]-pyrimidine-5-carboxylic acid ethyl ester (18.05 g, 89%) as a brown columnar crystal. mp: 126-129° C.

Workup

  1. temperatureheated
  2. temperatureat reflux over 3 hours
  3. extractionextracted with 300 ml of toluene
  4. washThe extract was washed with saturated saline solution
  5. dry with materialdried with magnesium sulfate
  6. concentrationconcentrated in vacuo
  7. customThe resulting residue was purified by silica gel column chromatography (ethyl acetate:toluene=8:2)

Sources & evidence

ORD record
ord-8ed00fc09b824d49a03b196ae397820c
Source dataset
uspto-grants-2010_02
Patent number
US07662826B2

Reaction notes

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