反应详情

A slurry of t-butyl 2-amino-5-(3-hydroxybenzoyl)-4-methyl-3-thenoate in 150 ml of 1:5 acid (see Example 1-C) was cooled to 0° to 5° C. and 9 ml of concentrated sulfuric acid was added below 5° C. A solution of 4.21 g (0.61 mole) of sodium nitrite in 10 ml of water was slowly added, holding the temperature at 0° to 5° C. during the addition. The diazonium was stirred for 1.5 hours at 0° to 5° C. and then was added below 10° C. to a solution of 11.34 g of 2-amino-5-bromo-3-pyridinol (Example 2-L) dissolved in 30 ml of pyridine and 25 ml of 2:5 acid. The mixture was stirred for 2 hours at 0° to 5° C., then poured into cold water. The resulting mixture was filtered, washed with water, air dried and recrystallized from ethyl cellosolve to give 23 g (72 percent) of a red solid, used without further purification.

1. customat 0° to 5° C.
2. additionduring the addition
3. filtrationThe resulting mixture was filtered
4. washwashed with water, air
5. customdried
6. customrecrystallized from ethyl cellosolve