Benzaldehyde → HCID 22675556, compound

Temperature

-60 °C

A solution of sieve dried di-isopropylamine (3.24 g, 32 mM) in THF (20 ml) was cooled to -50° C. under argon and treated with n-butyl lithium (1.6M in hexrine, 19.2 ml). A suspension of 2-methyl nicotinic acid (2.0 g, 14.6 mmol) in THF (70 ml) was added slowly by syringe to the reaction mixture. A deep red/purple colour developed. The reaction was stirred for 0.75 hours allowing the temperature to rise to -40° C. The reaction was cooled to -60° C. A solution of benzaldehyde (1.86 g, 17.52 mmol) in THF (10 ml) was added dropwise keeping the temperature below -60° C. The colour of the reaction discharged to pale yellow within 15 minutes. The cooling bath was removed and the reaction was allowed to warm to 0° C. and was held at 0° C. for 18 hours. Water was added and the reaction acidified to pH2 with 1N HCl and extracted with EtOAc. The pH of the aqueous phase was adjusted to pH5 and re-extracted with EtOAc. The organic layers were combined, dried (56 mg) and evaporated. The resulting pale yellow oil was purified by chromatography eluting with (methanol/dichloromethane) to give 2-phenyl-8-oxopyrano[4,3-b]pyridine as a yellow oil (1.5 g) MS (CI+): 226 [M+H]+.

1. additionwas added slowly by syringe to the reaction mixture
2. customto rise to -40° C
3. customthe temperature below -60° C
4. custompale yellow within 15 minutes
5. customThe cooling bath was removed
6. temperatureto warm to 0° C.
7. waitwas held at 0° C. for 18 hours
8. additionWater was added
9. extractionextracted with EtOAc
10. extractionre-extracted with EtOAc
11. customdried (56 mg)
12. customevaporated
13. customThe resulting pale yellow oil was purified by chromatography
14. washeluting with (methanol/dichloromethane)

ORD record

ord-2ce412bdef544b2aad9c72fc3076abed

Source dataset

uspto-grants-1998_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05834468