4,6-Dichloro-5-nitropyrimidine → 5-Amino-4,6-dichloropyrimidine

A mixture of 4,6-dichloro-5-nitroprimidine (E-1) (20.0 g, 104 mmmol) and stannous chloride dihydrate (117.7 g, 520 mmol) in EtOH (300 mL) is stirred at reflux for 2 h. The resulting mixture is allowed to cool to RT and then concentrated in vacuo. The residue is poured into ice water (300 mL) and neutralized with saturated NaHCO3 aqueous solution to adjust the pH value to 5-6. The resulting mixture is stirred at RT for 30 min and then extracted with ethyl acetate (3×200 mL). The combined organic layers are washed with brine, dried over Na2SO4 and filtered. The filtrate is concentrated in vacuo to afford the product, 4,6-dichloropyrimidine-5-amine (E-2).

1. temperatureat reflux for 2 h
2. concentrationconcentrated in vacuo
3. additionThe residue is poured into ice water (300 mL)
4. stirringThe resulting mixture is stirred at RT for 30 min
5. extractionextracted with ethyl acetate (3×200 mL)
6. washThe combined organic layers are washed with brine
7. dry with materialdried over Na2SO4
8. filtrationfiltered
9. concentrationThe filtrate is concentrated in vacuo

ORD record

ord-cbfc74c29e004af391c51bf7592eea99

Source dataset

uspto-grants-2016_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09388183B2