Chlorosuccinimide → N-(4,5-Dichloropyridin-2-yl)pivalamide

Temperature

100 °C

This compound was prepared as reported by K. S. Gudmundsson et al, Synthetic Communications 1997, 27 (5), 861-870: To a stirred solution of 4-chloro-2-trimethylacetamido-pyridine (0.870 g, 4.07 mmol) in anhydrous acetonitrile (11 ml) was added N-chlorosuccinimide (2.72 g, 20.37 mmol). The reaction mixture was heated at 100° C. for 3 h then more N-chlorosuccinimide (0.600 g) was added and stirring was continued at this temperature for 2 h. The mixture was then allowed to cool to room temperature, the solvent was removed in vacuo, and the residue was partitioned between ethyl acetate (170 ml) and 10% aqueous NaOH (60 ml). The organic layer was washed with 10% aqueous NaOH (60 ml), water (60 ml), saturated brine (60 ml), dried (Na2SO4), and concentrated in vacuo. The residue was absorbed on silica gel (2.3 g) and the free running powder was placed on a 50 g isolute silica column. Elution with 15% ethyl acetate in hexanes and 20% ethyl acetate in hexanes afforded the title compound as a white solid (0.500 g, 50%); 1H-NMR (250 Mz, CDCl3) 1.35 (s, 9H, C(CH3)3), 8.05 (br s, 1H, CONH), 8.28 (s, 1H), 8.52 (s, 1H) (3-H, 6-H).

1. customThis compound was prepared
2. temperatureto cool to room temperature
3. customthe solvent was removed in vacuo
4. customthe residue was partitioned between ethyl acetate (170 ml) and 10% aqueous NaOH (60 ml)
5. washThe organic layer was washed with 10% aqueous NaOH (60 ml), water (60 ml), saturated brine (60 ml)
6. dry with materialdried (Na2SO4)
7. concentrationconcentrated in vacuo
8. customThe residue was absorbed on silica gel (2.3 g)
9. washElution with 15% ethyl acetate in hexanes and 20% ethyl acetate in hexanes

ORD record

ord-cb643d8261a64b62a332228146b83604

Source dataset

uspto-grants-2012_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08088761B2