Water → 2-Bromo-5-(1,3-dioxan-2-yl)pyridine

To a solution of 6-bromopyridine-3-carbaldehyde 7 (47.2 g, 254 mmol) in toluene (130 mL) in a 250 mL round-bottom flask was added 1,3-propanediol (38.6 g, 508 mmol) and 10-camphorsulfonic acid (2.95 g, 12.69 mmol). The reaction mixture was heated to reflux, with azeotropic removal of the evolved water, for 1 h, cooled down to r.t. and concentrated. The residue was partitioned between EtOAc (150 mL) and NaHCO3 soln (100 mL). Organic phase was collected and the aqueous phase was extracted with EA (2×150 mL). Combined organic fractions were washed with brine (100 mL), dried over Na2SO4, filtered and concentrated to yield a brown solid which was triturated with Et2O/Hex (10/150 mL) for 1 h, filtered to give 28 (53.98 g, 221 mmol, 87% yield) as a beige solid. MS (m/z): 243.1 (M+1)

1. temperatureThe reaction mixture was heated
2. concentrationconcentrated
3. customThe residue was partitioned between EtOAc (150 mL) and NaHCO3 soln (100 mL)
4. customOrganic phase was collected
5. extractionthe aqueous phase was extracted with EA (2×150 mL)
6. washCombined organic fractions were washed with brine (100 mL)
7. dry with materialdried over Na2SO4
8. filtrationfiltered
9. concentrationconcentrated
10. customto yield a brown solid which
11. customwas triturated with Et2O/Hex (10/150 mL) for 1 h
12. filtrationfiltered

ORD record

ord-b9180e1bb1914c03bc3be999b096179a

Source dataset

uspto-grants-2015_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09018378B2