1-Tetralone → (2E)-3,4-Dihydro-2-[(4-methoxyphenyl)methylene]-1(2H)-naphthalenone

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Reaction Steps

A mixture of p-methoxybenzaldehyde (10.00 g, 73.4 mmol, 1.3 eq) and 1-tetralone (8.24 g, 56.4 mmol, 1 eq) was dissolved in tetrahydrofurane (30 mL) and a methanolic solution of potassium hydroxide (4% solution, 250 mL, 7.9 g KOH, 141 mmol, 2.5 eq) was added dropwise over a 15 minutes period to the stirred solution. The mixture was stirred at ambient temperature for three days and the formed precipitate was separated by filtration and purified by washing with MTBE. After drying in vacuo a pale yellow solid (8.57 g, 60% yield, GC-MS purity 99%) was obtained. The filtrate was reduced to a quarter of its volume and a second fraction (3.7 g, 26% yield, GC-MS purity 100%) could be isolated after filtration and washing with a low amount of methanol and a higher amount of MTBE. The over-all yield was 86% and the product was directly used in the next step without any further purification.

Provenance & Evidence