Diisopropylamine → Methyl 2-pyridazin-3-ylacetate

Temperature

0 °C

To a solution of diisopropylamine (19 ml, 130 mmol, 1.3 equiv) in dry THF (100 mL) at 0° C. under a N2, was added n-butyllithium (81 ml, 130 mmol, 1.3 equiv) slowly. The mixture was stirred at 0° C. for 30 min and then cooled to −78° C. A solution of 3-methylpyridazine (9 ml, 100 mmol, 1.0 equiv) in THF (50 mL) was added dropwise over a period of 1:5 min. The resulting mixture was stirred at −78° C. for 1 h, and a solution of dimethyl carbonate (17 ml, 200 mmol, 2 equiv) in THF (50 mL) was added dropwise. The mixture was allowed to warm slowly to 25° C. and stirred for 2 days. Sat.NH4Cl was added and the resulting solution was extracted with 10% MeOH/DCM. The combined organics were washed with water and brine, dried over Na2SO4 and concentrated. The residue was purified by flash chromatography (2.5% MeOH/DCM) to give 1.6 g of methyl 2-(pyridazin-3-yl)acetate as a brown liquid (11 mmol, 11%).

1. temperaturecooled to −78° C
2. custom5 min
3. stirringThe resulting mixture was stirred at −78° C. for 1 h
4. temperatureto warm slowly to 25° C.
5. stirringstirred for 2 days
6. extractionthe resulting solution was extracted with 10% MeOH/DCM
7. washThe combined organics were washed with water and brine
8. dry with materialdried over Na2SO4
9. concentrationconcentrated
10. customThe residue was purified by flash chromatography (2.5% MeOH/DCM)

ORD record

ord-b0357e1f31cf4842a8e1a6bcc7e9b82d

Source dataset

uspto-grants-2014_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08772296B2