Tetrahydrofuran → HCID 86752621, compound

HRID 1292120Notes

Reaction equation

C[Si]([N-][Si](C)(C)C)(C)C.[K+].[CH3:11][O:12][C:13]([CH2:15][CH2:16][N:17]([CH2:25][CH2:26][CH3:27])[CH:18]([CH2:23][CH3:24])[C:19](OC)=O)=[O:14].[O:28]1CCCC1>C1(C)C=CC=CC=1>[C:13]([C@@H:15]1[CH2:16][N:17]([CH2:25][CH2:26][CH3:27])[C@@H:18]([CH3:19])[CH2:23][C:24]1=[O:28])([O:12][CH3:11])=[O:14]

Participants

Conditions

Temperature: -20 °C

Procedure

To a stirred solution of 162 mL of 0.5M potassium bistrimethylsilylamide in toluene and 600 mL of anhydrous tetrahydrofuran cooled to -78° C. under nitrogen atmosphere was added dropwise a solution of 7.5 g of (±)-methyl 2-(2-methoxycarbonylethyl(1-propyl)amino)butyrate in 50 mL of dry (tetrahydrofuran over 20 min, keeping the internal temperature under -70° C. The mixture was allowed to warm to -20° C. for 2 h, then quenched with 100 mL of saturated aqueous sodium bicarbonate and extracted into 3×200 mL portions of ethyl acetate. The combined extracts were dried over MgSO4 and concentrated under reduced pressure. There was obtained 6.6 g of predominantly (±)-trans-5-carbomethoxy-2-methyl-4-oxo-1-propyl piperidine as an oil: TLC (EtOAc); 1H NMR (400 MHz, CDCl3) 3.76 (s, 3H), 3.2 (m, 1H), 2.9 (m, 1H), 2.62-2.0 (complex m, 6H), 1.5 (m, 2H), 1.25 (d, 3H), 0.5 (dd, 3H).

Workup

dry with materialof dry (tetrahydrofuran over 20 min
customunder -70° C
customquenched with 100 mL of saturated aqueous sodium bicarbonate
extractionextracted into 3×200 mL portions of ethyl acetate
dry with materialThe combined extracts were dried over MgSO4
concentrationconcentrated under reduced pressure

Sources & evidence

ORD record: ord-14f722cea0d14d88b81a99fb310da095
Source dataset: uspto-grants-1998_05
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US05756508

Reaction notes

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