Water → 1-Benzyl-4-butylidenepiperidine

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Reaction Steps

A 500 mL 3-necked flask fitted with a stirrer, was charged with sodium hydride (1.61 g, 67 mmol) and DMSO (40 mL). The resulting suspension was heated to 90° C. for 30 min, until the evolution of hydrogen ceased. The suspension was cooled on an ice-bath for 20 min followed by addition of a slurry of butyltriphenylphosphonium bromide (26.6 g, 67 mmol) in DMSO (70 mL). The red mixture was stirred for 15 min at rt. 1-Benzyl4-piperidone 1 (14.0 g, 74 mmol) was slowly added over 30 min, and the mixture was stirred at room temperature over night. H2O (200 mL) was added to the reaction mixture followed by extraction with heptane (4×100 mL) and ethyl acetate (2×100 mL). The combined organic phases were dried and evaporated to dryness, producing 38.1 g of a yellow oil. The oil was distilled to give 14.9 g (88%) of 2, bp 101-105° C. (0.1 mm Hg). 1H NMR (CDCl3) δ0.90-0.95 (t, 3H), 1.25 1.41 (m, 2H), 1.90-2.20 (m, 2H), 2.18-2.30 (m, 4H), 2.40-2.45 (m, 4H), 2.50 (s, 2H), 5.17 (t, 1H), 7.20-7.42 (m, 5H).

Provenance & Evidence