1-Methyl-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole → 4-[5-Methyl-4-(1-methyl-1H-pyrazol-4-yl)-2-nitro-phenoxy]-piperidine-1-carboxylic acid tert-butyl ester

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A mixture of 4-(4-Chloro-5-methyl-2-nitro-phenoxy)-piperidine-1-carboxylic acid tert-butyl ester from the previous step (375.8 mg, 1.01 mmol), 1-Methyl-4-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-1H-pyrazole (Boron Molecular, 224.4 mg 1.08 mmol), potassium phosphate tribasic monohydrate (392 mg), Pd2(dba)3 (45 mg), and dicyclophosphinobiphenyl (43 mg) in 4 mL of 1,4-dioxane/H2O (3/1) is heated in a sealed tube at 150° C. for 20 min under microwave radiation. The reaction mixture is filtered through a small plug of Celite, dried over Na2SO4 and concentrated. The residue is purified using a SiO2 column (ISCO), affording 4-[5-Methyl-4-(1-methyl-1H-pyrazol-4-yl)-2-nitro-phenoxy]-piperidine-1-carboxylic acid tert-butyl ester. MS (ES+); 417.3 (MH+), 439.2 (MNa+).

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