Ethyl Acetate → 6-Chloropyridine-2,3-diamine

Temperature

60 °C

A mixture of 12.0 g of 2-amino-6-chloro-3-nitro-pyridine, 78.0 g of tin(II) chloride dihydrate and 360 ml of a 9:1 by volume mixture of ethyl acetate and 2-methyl-2-propanol was stirred at 60° C. for 1 hour, after which 1.32 g of sodium borohydride were added at 60° C., and the mixture was stirred for 3 hours at the same temperature. At the end of this time, the reaction mixture was freed from the solvent by distillation under reduced pressure. The resulting residue was diluted with water and neutralized by adding an aqueous solution of potassium carbonate, after which it was extracted with ethyl acetate. The extract was washed with an aqueous solution of sodium chloride and dried over anhydrous sodium sulfate, after which the solvent was removed by distillation under reduced pressure. The residue thus obtained was crystallized by trituration with a mixture of ethyl acetate and hexane, to give 6.50 g of title compound, melting at 120-122° C.

1. stirringthe mixture was stirred for 3 hours at the same temperature
2. distillationAt the end of this time, the reaction mixture was freed from the solvent by distillation under reduced pressure
3. additionThe resulting residue was diluted with water
4. additionby adding an aqueous solution of potassium carbonate
5. extractionafter which it was extracted with ethyl acetate
6. washThe extract was washed with an aqueous solution of sodium chloride
7. dry with materialdried over anhydrous sodium sulfate
8. customafter which the solvent was removed by distillation under reduced pressure
9. customThe residue thus obtained
10. customwas crystallized by trituration with a mixture of ethyl acetate and hexane

ORD record

ord-2d927c2ca2584ca69cd659ca3fc0a14a

Source dataset

uspto-grants-2000_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06117893