反应详情

Formic acid (13 ml, 0.33 m) was added to 31.2 ml (0.33 m) of acetic acid stirred in an ice bath. The mixture was stirred 15 minutes at 0° C. and 15 minutes at 55° C. It was then recooled to 0° C. and 8.1 g (0.033 m) of ethyl 1-amino-1,4-dihydro-7-methyl-4-oxo-1,8-naphthyridine-3-carboxylate was added. An additional 9.2 ml of formic acid was then added, and the reaction mixture was stirred one hour at 0° C. and two hours at room temperature. The reaction mixture was poured into ice-water, and the solid product collected by filtration, washed with water, tetrahydrofuran and ether, and dried at 75° C. in vacuo to give 4.4 g of ethyl 1-(formylamino)-1,4-dihydro-7-methyl-4-oxo-1,8-naphthyridine-3-carboxylate, m.p. 214° C. (decompn), which contained a minor amount of the corresponding N,N-diformyl compound.

1. stirringThe mixture was stirred 15 minutes at 0° C. and 15 minutes at 55° C
2. customwas then recooled to 0° C.
3. stirringthe reaction mixture was stirred one hour at 0° C. and two hours at room temperature
4. filtrationthe solid product collected by filtration
5. washwashed with water, tetrahydrofuran and ether
6. customdried at 75° C. in vacuo