Pyridine → 5-tert-Butyl-2-p-tolyl-2H-pyrazole-3-carboxylic acid ethyl ester

HRID 2075587Notes

Reaction equation

HRID 2075587 reaction equation
[CH2:1]([O:3][C:4]([C:6]1[NH:7][N:8]=[C:9]([C:11]([CH3:14])([CH3:13])[CH3:12])[CH:10]=1)=[O:5])[CH3:2].N1C=CC=CC=1.B(O)(O)[C:22]1[CH:23]=[CH:24][C:25]([CH3:28])=[CH:26][CH:27]=1>C(Cl)Cl.CC([O-])=O.CC([O-])=O.[Cu+2]>[CH2:1]([O:3][C:4]([C:6]1[N:7]([C:22]2[CH:27]=[CH:26][C:25]([CH3:28])=[CH:24][CH:23]=2)[N:8]=[C:9]([C:11]([CH3:13])([CH3:12])[CH3:14])[CH:10]=1)=[O:5])[CH3:2]

Participants

6

Reactant 3

HCID 1049PyridineHCID 79799Tolylboronic acidHCID 2743509Ethyl 3-tert-butyl-1H-pyrazole-5-carboxylate

Product 1

HCID 574185545-tert-Butyl-2-p-tolyl-2H-pyrazole-3-carboxylic acid ethyl esterYield 86%

Reagents, catalysts & solvents 2

HCID 8895Cupric acetateCatalystHCID 6344DichloromethaneSolvent

Procedure

To a round bottom flask containing 5-tert-Butyl-2H-pyrazole-3-carboxylic acid ethyl ester (0.5 g, 2.6 mmol) stirring in 25 mL DCM was added Pyridine (0.95 mL, 11.7 mmol), p-tolylboronic acid (1.1 g, 8.1 mmol), Cu(OAc)2 (0.75 g, 4.1 mmol) and 4 A molecular sieves (0.75 g). The reaction stirred at room temperature for 14 h under air. The resulting mixture was filtered through a pad of diatomaceous earth and the filtrate concentrated in vacuo to afford a light green solid. The crude material was purified by Flash chromatography to afford (0.64 g, 83%) the desired product as a clear oil (0-50% EtOAc:hexanes on silica gel). Expected mass=286. Observed mass=287.

Workup

  1. filtrationThe resulting mixture was filtered through a pad of diatomaceous earth
  2. concentrationthe filtrate concentrated in vacuo
  3. customto afford a light green solid
  4. customThe crude material was purified by Flash chromatography

Sources & evidence

ORD record
ord-663bc96e9d08482db6e44c8490a42b94
Source dataset
uspto-grants-2011_04
Patent number
US07919617B2

Reaction notes

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