Chlorotrimethylsilane → 3-(1-Methylpyrrolidin-2-yl)-1,4-bis-trimethylsilanyl-1,4-dihydropyridine

Temperature

0 °C

To a suspension of lithium powder (0.42 g, 60 mmol) in freshly distilled THF (20 mmol) cooled at−10° C. was added freshly distilled trimethylchlorosilane (7.6 mL, 60 mmol). A solution of (S)-nicotine (3.2 mL, 20 mmol) in THF (20 mL) was injected dropwise over 20 min. The reaction mixture was stirred at 0° C. for 1 h. The precipitate formed was decanted over 2 h and the liquid portion was canulated into a 2 neck flask mounted with a distillation apparatus under Ar. After removal of the THF by distillation at atmospheric pressure, the product was distilled under vacuum (1.5 mm Hg, bp=130-135° C.) to give 71% (4.36 g) of 3-(1-methylpyrrolidin-2-yl)-1,4-bis-trimethylsilanyl-1,4-dihydropyridine i as a yellow oil (95% pure by NMR). 1H NMR (400 MHz, CDCl3): 67 8.24 (s, 1 H), 5.78-5.72 (m, 1 H), 4.37-4.29 (m, 1 H), 3.06-2.93 (m, 1 H), 2.4-1.4 (m, 10 H), 0.08 (s, 9 H), −0.05 (s, 9 H). 13C NMR (100 MHz, CDCl3) δ 127.49, 126.41, 121.14, 102.08, 101.00, 66.67, 57.21, 41.05, 32.52, 26.41, 21.84, −0.83, −0.90, −2.43, −2.64. HRMS Calcd for C16H32N2Si2: 309.2182 [M+H]+. Found: 309.2166 [M+H]+.

1. customThe precipitate formed
2. customwas decanted over 2 h
3. customAfter removal of the THF
4. distillationby distillation at atmospheric pressure
5. distillationthe product was distilled under vacuum (1.5 mm Hg, bp=130-135° C.)

ORD record

ord-071fad3871a44f0f87c7ed2129af6540

Source dataset

uspto-grants-2008_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07361768B2