反应详情

The product of stage (a) (19.5 g) was dissolved in glacial acetic acid (100 ml) and was treated with sodium nitrite (4.4 g) in water (15 ml) at 10° C. The precipitated solid was filtered off, washed, dried and recrystallised from methanol to yield 9.7 g of desired product, mp 159°-160° C.

1. filtrationThe precipitated solid was filtered off
2. washwashed
3. customdried
4. customrecrystallised from methanol