1,4-Dioxane → 3-Amino-5-bromo-1-methyl-1,2-dihydropyridin-2-one

To a solution of 5-bromo-3-(diphenylmethyleneamino)-1-methylpyridin-2(1H)-one (3.82 g, 10.4 mmol) in ethyl acetate (10 mL) was added 4 MHCl/dioxane (7.8 mL, 31.3 mmol). The reaction mixture was stirred for 0.5 h and concentrated under reduced pressure. The residue was washed with tert-butyl methyl ether and filtered. The solid was dissolved in ethyl acetate (10 mL) and water (10 mL). The pH of the resulting mixture was adjusted to between 7 and 8 by adding K2CO3 gradually. The water phase was separated and extracted with dichloromethane for three times. The combined organic layer was concentrated under reduced pressure to afford 325a as a yellow solid (1.1 g, 52%). MS-ESI: [M+H]+ 202.9.

1. concentrationconcentrated under reduced pressure
2. washThe residue was washed with tert-butyl methyl ether
3. filtrationfiltered
4. dissolutionThe solid was dissolved in ethyl acetate (10 mL)
5. additionby adding K2CO3 gradually
6. customThe water phase was separated
7. extractionextracted with dichloromethane for three times
8. concentrationThe combined organic layer was concentrated under reduced pressure

ORD record

ord-db3c1962a4914833aaea7a34dee52ff3

Source dataset

uspto-grants-2014_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08716274B2