反应详情

To a stirred solution of 5-methyl pyrazine carboxylic acid (13.8 g, 100 mmol) in 300 mL of toluene at room temperature under nitrogen was added triethyl amine (14 mL, 100 mmol) followed by diphenyl phosphoryl azide (21.6 mL, 100 mmol). After 30 min. at room temperature, 2-methyl-2-propanol (19 mL, 200 mmol) was added and the solution immersed in a 90 ° C. oil bath. After 2 hours, the reaction was cooled to RT, diluted to 600 mL with EtOAc, and washed 3×60 mL with 10% Na2CO3 and 1×600 mL with saturated NaCl. The organics were dried (MgSO4), filtered and concentrated to a yellow solid (17.5 g, 83%). 1H-NMR (400 MHz, CDCl3) δ9.16 (s, 1H), 8.05 (s, 1H), 7.56 (br s, 1H), 2.50 (s, 3H), 1.55 (s, 9H)

1. customimmersed in a 90 ° C.
2. waitAfter 2 hours
3. washwashed 3×60 mL with 10% Na2CO3 and 1×600 mL with saturated NaCl
4. dry with materialThe organics were dried (MgSO4)
5. filtrationfiltered
6. concentrationconcentrated to a yellow solid (17.5 g, 83%)