2-Amino-6-methylpyridine → 2-Amino-5-chloro-6-methylpyridine

Temperatur

0 °C

To a stirred solution of 2-amino-6-methylpyridine (10.80 g, 100.0 mmol) in dry DMF (50 mL) was added dropwise a solution of NCS (13.35 g, 100.0 mmol) in dry DMF (60 mL) at 0° C. over 20 min. The resulting brown yellow solution was stirred at 0° C. for 1 h, and at room temperature for 3 h, then poured into ice-water (about 300 mL). The resulting mixture was extracted with EtOAc (4×100 mL). The extracts were combined, washed with brine (6×50 mL), dried (MgSO4), and rota-evaporated. To the residual viscous black oil was added hexane (200 mL) and it was heated to boiling with stirring. The hot hexane solution was decanted carefully, concentrated to about 60 ml, then allowed to stand at room temperature overnight. The resulting crystals were filtered and dried at room temperature in vacuo, giving 6.06 g (42%) of 45 as orange-colored long needles, mp 74°-5° C. (lit. 73°-4° C., Cress et al., J. Org. Chem. 93-6 (1976)). 1H NMR (CDCl3) δ2.439 (s, 3H), 4.376 (bs, 2H), 6.302 (d, 1H, J=8.5), 7.340 (d, 1H, J=8.5).

1. waitat room temperature for 3 h
2. extractionThe resulting mixture was extracted with EtOAc (4×100 mL)
3. washwashed with brine (6×50 mL)
4. dry with materialdried (MgSO4)
5. customrota-evaporated
6. additionTo the residual viscous black oil was added hexane (200 mL) and it
7. temperaturewas heated
8. stirringwith stirring
9. customThe hot hexane solution was decanted carefully
10. concentrationconcentrated to about 60 ml
11. waitto stand at room temperature overnight
12. filtrationThe resulting crystals were filtered
13. customdried at room temperature in vacuo

ORD-Eintrag

ord-53f47df6133a47f49e6401d3f3ab28e6

Quelldatensatz

uspto-grants-1997_04

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US05620978