Ammonia → Ethyl 4-chloro-6-ethoxy-7-methyl-1,8-naphthyridine-3-carboxylate
Reaction equation
[CH2:1]([O:3][C:4]1[CH:5]=[C:6]2[C:11](=[N:12][C:13]=1[CH3:14])[N:10]=[CH:9][C:8]([C:15]([O:17][CH2:18][CH3:19])=[O:16])=[C:7]2O)[CH3:2].N.P(Cl)(Cl)([Cl:24])=O>>[Cl:24][C:7]1[C:6]2[C:11](=[N:12][C:13]([CH3:14])=[C:4]([O:3][CH2:1][CH3:2])[CH:5]=2)[N:10]=[CH:9][C:8]=1[C:15]([O:17][CH2:18][CH3:19])=[O:16]Participants
4
Procedure
Ethyl 6-ethoxy-4-hydroxy-7-methyl-1,8-naphthyridine-3-carboxylate (2.5 g) was added to phosphorus oxychloride (20 ml) with stirring at ambient temperature. The mixture was warmed to 40° C. and kept at this temperature for 1 hour then cooled to 10° C. The mixture was added to excess ice/water and the mixture basified with aqueous ammonia solution (specific gravity 0.88) while keeping the temperature below 5° C. The product was extracted into dichloromethane. The combined dichloromethane extracts were evaporated under reduced pressure at ambient temperature to give ethyl 4-chloro-6-ethoxy-7-methyl-1,8-naphthyridine-3-carboxylate, m.p. >250° C.
Workup
- temperatureThe mixture was warmed to 40° C.
- temperaturethen cooled to 10° C
- customthe temperature below 5° C
- extractionThe product was extracted into dichloromethane
- customThe combined dichloromethane extracts were evaporated under reduced pressure at ambient temperature
Sources & evidence
- ORD record
- ord-4192db93739e4b77a2c6ca1b1c0a3eec
- Source dataset
- uspto-grants-1995_11
- Patent number
- US05464781
Reaction notes
Loading…