1,2-Dibromoethane → 7-bromo-2H,3H-[1,4]dioxino[2,3-b]pyridine

Temperature

100 °C

To a suspension of 5-Bromo-pyridine-2,3-diol (10.0 g, 52.63 mmol, commercially available, CAS 34206-49-0) in DMF (150 mL) was added K2CO3 (21.78 g, 158 mmol) and 1,2-dibromo ethane (11.87 g, 63.2 mmol). The reaction mixture was heated to 100° C. for 5 h. The reaction mixture was cooled to rt and poured into ice cold water EtOAc was added and the phases were separated and the aq layer was extracted with more ethyl acetate. The combined organic layers was dried over anhydrous Na2SO4 and concentrated under vacuo to get the crude compound. The crude compound was purified by silica gel chromatography (eluent 10% ethyl acetate in petrol ether). Yield of 6-Bromo-[1,3]dioxolo[4,5-b]pyridine 2.2 g (18%) pure by 1H NMR (400 MHz, DMSO) δ 7.85 (d, 1H, J=2 Hz), 7.59 (d, 1H, J=2 Hz), 4.41 (m, 2H), 4.27 (m, 2H).

1. temperatureThe reaction mixture was cooled to rt
2. additionpoured into ice cold water EtOAc
3. additionwas added
4. customthe phases were separated
5. extractionthe aq layer was extracted with more ethyl acetate
6. dry with materialThe combined organic layers was dried over anhydrous Na2SO4
7. concentrationconcentrated under vacuo

ORD record

ord-37427c407c714e46b0ff1f1f0cf4672f

Source dataset

uspto-grants-2013_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08598213B2