Formaldehyde → HCID 71512056, compound

Temperature

40 °C

2-Chloro-5-iodopyridin-4-amine (2.0 g, 7.86 mmol) and paraformaldehyde (0.472 g, 15.7 mmol) were dissolved in AcOH (56.1 mL) and stirred for 2.5 hours at 40° C. Sodium triacetoxyborohydride (3.66 g, 17.3 mmol) was added and the mixture was stirred at 40° C. for 1.5 hours. Further sodium triacetoxyborohydride (3.66 g, 17.3 mmol) was added and the mixture was stirred for a further 19 hours. The reaction mixture was reduced in volume by half by evaporation in vacuo. Water was added to the mixture, followed by basification with NaHCO3. The mixture was extracted with EtOAc (3×70 mL) and the combined organic layers were dried over MgSO4. Silica was added and the solution was concentrated. Gradient chromatography, eluting with 5-10% EtOAc in c-Hex for 4 column volume and then 10% EtOAc in c-Hex for a further 11 column volume, gave 2-chloro-5-iodo-N-methylpyridin-4-amine (1.65 g, 6.14 mmol, 78% yield) as a white crystalline powder.

1. stirringthe mixture was stirred at 40° C. for 1.5 hours
2. stirringthe mixture was stirred for a further 19 hours
3. customThe reaction mixture was reduced in volume by half by evaporation in vacuo
4. additionWater was added to the mixture
5. extractionThe mixture was extracted with EtOAc (3×70 mL)
6. dry with materialthe combined organic layers were dried over MgSO4
7. additionSilica was added
8. concentrationthe solution was concentrated
9. washGradient chromatography, eluting with 5-10% EtOAc in c-Hex for 4 column volume

ORD record

ord-12c4c636fd54486684e34d77a2dba515

Source dataset

uspto-grants-2016_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09403797B2