反应详情

温度

95 °C

To tert-butyl 5-chloro-3-formylpyrazolo[1,5-a]pyrimidin-7-yl(cyclopropyl)carbamate (1 g, 2.97 mmol) in 30 mL of a 2:1 mixture of 1,2-dimethoxyethane/EtOH was added 2-carboxythiophene-5-boronic acid (766 mg, 4.45 mmol), tetrakis(triphenylphosphine)palladium(0) (171 mg, 0.148 mmol), and 2M aqueous solution of Na2CO3 (4.45 mL, 8.91 mmol). The mixture was stirred at 95° C. for 3 hours then cooled to room temperature and partitioned between 2N NaOH and ethyl acetate. The layers were separated and the aqueous layer was acidified to pH<3 with conc. HCl. The aqueous layer was extracted (3×) with methylene chloride. The combined organic layers was washed with brine, dried over MgSO4, filtered, and evaporated to dryness to provide 450 mg of 5-(7-(tert-butoxycarbonyl(cyclopropyl)amino)-3-formylpyrazolo[1,5-a]pyrimidin-5-yl)thiophene-2-carboxylic acid. Some additional material which was in the first ethyl acetate layer was purified by silica gel chromatography (0%-20% MeOH/CH2Cl2) to provide another 550 mg of 5-(7-(tert-butoxycarbonyl(cyclopropyl)amino)-3-formylpyrazolo[1,5-a]pyrimidin-5-yl)thiophene-2-carboxylic acid (79%). LCMS (M+1=429)

1. temperaturethen cooled to room temperature
2. custompartitioned between 2N NaOH and ethyl acetate
3. customThe layers were separated
4. extractionThe aqueous layer was extracted (3×) with methylene chloride
5. washThe combined organic layers was washed with brine
6. dry with materialdried over MgSO4
7. filtrationfiltered
8. customevaporated to dryness