Hydrochloric Acid → 4-(5-Methoxymethyl-5-methyl-2,3,4,5-tetrahydrobenzo[b]oxepin-8-ylethynyl)-benzoic acid

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Reaction Steps

20.06 g (55.04 mmol) of 4-(5-methoxymethyl-5-methyl-2,3,4,5-tetrahydrobenzo[b]oxepin-8-ylethynyl)-benzoic acid methyl ester was dissolved in 100 ml of THF/ethanol (1/1) and treated with 8.81 g (4 eq.) of NaOH, dissolved in 50 ml of water. The reaction flask was kept in the dark and stirring continued for 42 h at room temperature. The mixture was then poured onto crushed ice/60 ml of 25% HCl, extracted twice with ethylacetate; the organic phase was washed with a small amount of water, dried over sodium sulfate, filtrated, and evaporated to dryness. Crystallization from hexane/ethylacetate yielded 18.90 g of the title product as pale yellow crystals of m.p. 205-206° C.

Provenance & Evidence