Borane;tetrahydrofuran → (5-Chloropyridin-2-yl)methanol

5-Chloropyridine-2-carboxylic acid (2.00 g, 12.7 mmol) was dissolved in THF (12 mL) at 0° C. and added to a solution of borane-THF (19.0 mL, 1 M in THF, 19.0 mmol). THF (10 mL) was added and the reaction mixture was warmed to room temperature, stirred for 2 h and heated under reflux at 70° C. for 3 h. The reaction mixture was cooled to 0° C., quenched with aq 6 M HCl solution (4 mL) and the solution was stirred for 2 h and concentrated in vacuo. The residue was partitioned between H2O (75 mL) and DCM (75 mL). The aq layer was washed with DCM (3×75 mL), adjusted to pH 9 with 4 M aq NaOH (3 mL) and extracted with DCM (3×75 mL). The organic layers were combined, dried (MgSO4) and concentrated in vacuo to give 5-chloropyridine-2-methanol (0.83 g, 45%) as a brown gum.

1. temperatureheated
2. temperatureunder reflux at 70° C. for 3 h
3. temperatureThe reaction mixture was cooled to 0° C.
4. customquenched with aq 6 M HCl solution (4 mL)
5. stirringthe solution was stirred for 2 h
6. concentrationconcentrated in vacuo
7. customThe residue was partitioned between H2O (75 mL) and DCM (75 mL)
8. washThe aq layer was washed with DCM (3×75 mL)
9. extractionextracted with DCM (3×75 mL)
10. dry with materialdried (MgSO4)
11. concentrationconcentrated in vacuo

ORD-Eintrag

ord-337f765ec6d24e219deed0c70083162c

Quelldatensatz

uspto-grants-2015_05

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US09035066B2