Iodoethane → tert-Butyl (3-ethylpyridin-2-yl)carbamate

Temperature

-78 °C

2-t-Butoxycarbonylaminopyridine (10 g, 51.5 mmol) was dissolved in tetrahydrofuran (80 mL), and cooled to -78° C. N-butyllithium (80 mL of 1.49M in hexanes, 120 mmol) was added dropwise over a period of 1 h. After stirring for an additional 15 min at -78° C. and then for 2.5 hours at -10° C., the solution was then recooled back down to -78° C. and iodoethane (77.2 mmol, 6.18 mL) was added dropwise over a period of 15 min via syringe. The solution was allowed to warm to room temperature. The reaction was quenched with 100 mL of a saturated ammonium chloride and extracted with ethyl acetate (3×). The organic layers were collected, dried over magnesium sulfate, and concentrated. The resulting solid was purified by flash chromatography on silica gel (25% ethyl acetate/hexanes) to provide the 4.9 g (43%) of the titled product as a light brown solid: mp 101°-102° C.; IR (KBr, cm-1) 3174, 2968, 1725, 1594, 1519, 1442, 1278, 1249, 1156; 1H NMR (300 MHZ, DMSO-d6) δ 8.98 (s, 1 H), 8.17 (m, 1H), 7.61 (m, 1H), 7.15 (m, 1H), 2.52 (q, J=7.5 Hz, 2H), 1.39 (s, 9H), 1.08 (t, J=7.5 Hz, 3H); MS (FD) m/e 222 (M+); UV (EtOH) 270 nm (ε=4398), 223 nm (ε=6745). Anal. Calcd for C12H18N2O2 : C, 64.84; H, 8.16; N, 12.60. Found: C, 64.91; H, 8.34; N, 12.42.

1. waitfor 2.5 hours at -10° C.
2. customwas then recooled back down to -78° C.
3. temperatureto warm to room temperature
4. customThe reaction was quenched with 100 mL of a saturated ammonium chloride
5. extractionextracted with ethyl acetate (3×)
6. customThe organic layers were collected
7. dry with materialdried over magnesium sulfate
8. concentrationconcentrated
9. customThe resulting solid was purified by flash chromatography on silica gel (25% ethyl acetate/hexanes)

ORD record

ord-b167283a037440edb88a4ebd83c40e6c

Source dataset

uspto-grants-1997_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05658907