5-bromo-2-methylpentanoic acid

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: To a solution of 5-bromo-2-methyl-pentanoic acid (1.79 g, 9.2 mmol, 1 eq) in anhydrous DCM (8 mL) oxalyl chloride (1.0 mL, 12.0 mmol, 1.3 eq) was added dropwise and the mixture was stirred at room temperature for 16 hours. After evaporation of the solvent and the excess oxalyl chloride, the residue was dissolved in anhydrous DCM (8 mL) and a solution of 5-amino-3-(4-chloro-phenyl)-pyrazole-1-carboxylic acid tert-butyl ester (2.7 g, 9.2 mmol, 1.0 eq) and triethylamine (1.7 mL, 12 mmol, 1.3 eq) was added dropwise at 0° C. The mixture was allowed to reach room temperature and stirred at room temperature for 24 hours, after which another 0.5 eq of activated 5-bromo-2-methyl-pentanoic acid was added. HCl 1M was added; the crude was extracted with DCM and purified through SiO2 column (eluent DCM) to give 3.3 g (yield 97%) of the title product. After evaporation of the solvent the excess oxalyl chloride, the residue was dissolved in anhydrous DCM (8 mL) to reach room temperature stirred at room temperature for 24 hours the crude was extracted with DCM purified through SiO2 column (eluent DCM)

反应条件: temp:120.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: HBr aq 48% (10 mL, 88.4 mmol) was added at room temperature to 2-(3-bromo-propyl)-2-methyl-malonic acid dimethyl ester (1.80 g, 6.74 mmol) and the mixture was stirred and heated at 120° C. for 24 hours. After cooling to room temperature, NaOH solution was added to reach pH 3 and the product was extracted using a mixture DCM:MeOH 95:5. The obtained crude (0.81 g, 62% yield) was clean enough to be used without further purification. After cooling to room temperature the product was extracted The obtained crude (0.81 g, 62% yield) to be used without further purification