2,5-Dichloro-3-nitropyridine → 3-Amino-2,5-dichloropyridine

To a solution of 129.2 g (0.69 mol) of 2,5-dichloro-3-nitropyridine in 1300 ml of dioxane is added 26 0 g of Raney-nickel, that has previously been washed with ethanol. This mixture is then hydrogenated with hydrogen under normal pressure at 20-35° C. After uptake of 20% of the theoretical amount of hydrogen, another 30 g of washed Raney-nickel catalyst are added. After hydrogenating for 22 hours, the catalyst is filtered off, the solvent is evaporated and the residue is crystallized from hexane/ ethyl acetate. Thus, 84.9 g of 3-amino-2,5-dichloropyridine (78% of the theory) are obtained, which melts at 129-132° C.

1. washhas previously been washed with ethanol
2. customat 20-35° C
3. additionAfter uptake of 20% of the theoretical amount of hydrogen, another 30 g of washed Raney-nickel catalyst are added
4. filtrationthe catalyst is filtered off
5. customthe solvent is evaporated
6. customthe residue is crystallized from hexane/ ethyl acetate

ORD record

ord-8d30d97b9b8c459d91ec2676a6d2bd3c

Source dataset

uspto-grants-1990_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04935051