Formaldehyde → 2-Bromo-6-(hydroxymethyl)pyridin-3-ol

Potassium hydroxide (85% assay, 113.8 g, 1.73 mol) was dissolved in distilled water (750 ml) and to the solution was added 2-bromo-3-hydroxypyridine (300 g, 1.72 mol), ethylenediaminetetraacetic acid sodium salt (2 mmol %, 13.1 g, 0.034 mmol) and formalin (3741% w/v 470 ml, 5.95 mmol). The stirred mixture was heated at 90°-95° C. until the assay (HPLC) of remaining starting material fell below 3% (approx 5 h) . The reaction mixture was then cooled to room temperature and glacial acetic acid (103 ml) added and stirred for a further 2h. The precipitated solid was filtered from the mixture and the filtrate saturated with sodium chloride (310 g). The resulting solution was extracted with ethyl acetate (4×280ml). The combined organic extracts were dried and evaporated to dryness keeping the temperature below 85° C. The residue was assayed by HPLC to determine the quantity of contained 2-bromo-3-hydroxy-6-hydroxymethylpyridine. The yield was typically 65%.

1. temperatureThe stirred mixture was heated at 90°-95° C. until the assay (HPLC)
2. custombelow 3% (approx 5 h)
3. filtrationThe precipitated solid was filtered from the mixture
4. extractionThe resulting solution was extracted with ethyl acetate (4×280ml)
5. customThe combined organic extracts were dried
6. customevaporated to dryness
7. customthe temperature below 85° C

ORD-Eintrag

ord-f0870081d55e49e5b32b07b89efdd52e

Quelldatensatz

uspto-grants-1997_07

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US05646286