Water → 2-Chloro-N4-methylpyridine-3,4-diamine

10 g of (10) were dissolved in 50 ml of 12N HCl and the temperature brought to 90° C. 72.5 g di SnCl2.2H2O were added in five portions over the course of 1 minute. This was left stirring at 90° C. for 1 hour. After cooling the solution to room temperature, 100 ml of water were added and evaporated at reduced pressure. The residue was taken up in 100 ml of water, cooled to 0° C. and concentrated aqueous ammonia added, until the formation of a white, gelatinous precipitate. The pH was adjusted to 8.5-9 and the resulting emulsion centrifuged. The remaining solid residues were again taken up in water and centrifuged. The operation was repeated three times. The combined solid residues were left under stirring overnight in 50 ml of methylene chloride. The centrifuged aqueous phases were extracted three times with methylene chloride, then all the organic phases combined, then dried over anhydrous sodium sulphate and subsequently evaporated under vacuum, giving 6.2 g of (11) in the form of pink crystals.

1. custombrought to 90° C
2. waitThis was left
3. temperatureAfter cooling the solution to room temperature
4. customevaporated at reduced pressure
5. temperaturecooled to 0° C.
6. additionconcentrated aqueous ammonia added, until the formation of a white, gelatinous precipitate
7. waitThe combined solid residues were left
8. stirringunder stirring overnight in 50 ml of methylene chloride
9. extractionThe centrifuged aqueous phases were extracted three times with methylene chloride
10. dry with materialdried over anhydrous sodium sulphate
11. customsubsequently evaporated under vacuum

ORD record

ord-68205342a303411f970fe5893f61652d

Source dataset

uspto-grants-2009_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07528252B2