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

HRID 1365080Notes

Reaction equation

[Li].[CH3:2][Si:3]([CH3:6])([CH3:5])Cl.[N:7]1[CH:12]=[C:11]([C@@H:13]2[CH2:18][CH2:17][CH2:16][N:14]2[CH3:15])[CH:10]=[CH:9][CH:8]=1>C1COCC1>[CH3:15][N:14]1[CH2:16][CH2:17][CH2:18][CH:13]1[C:11]1[CH:10]([Si:3]([CH3:6])([CH3:5])[CH3:2])[CH:9]=[CH:8][N:7]([Si:3]([CH3:6])([CH3:5])[CH3:2])[CH:12]=1

Participants

Conditions

Temperature: -10 °C

Procedure

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): δ 8.24 (s, 1H), 5.78-5.72 (m, 1H), 4.37-4.29 (m, 1H), 3.06-2.93 (m, 1H), 2.4-1.4 (m, 10H), 0.08 (s, 9H), −0.05 (s, 9H). 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]+.

Workup

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

Sources & evidence

ORD record: ord-08a4361eb4a14074bf5ba75c098887a2
Source dataset: uspto-grants-2011_02
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07888512B2

Reaction notes

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