Ethanol → 3-Methyl-3-prop-2-ynyloxymethyl-1-oxa-4-aza-spiro[4.5]decane

Beteiligte Stoffe

Reaktionsschritte

Sodium hydride (55% in dispersion in oil) (0.636 g) was added portion wise to a solution of (3-methyl-1-oxa-4-aza-spiro[4.5]dec-3-yl)-methanol (2.0 g) in dry THF (30 ml) at 0° C. The reaction mixture was stirred at R.T. for 50′. Propargyl bromide (0.972 ml) was added dropwise at 0° C. and the resulting mixture was stirred at R.T. for 2 h 30. Additional sodium hydride (55% in dispersion in oil) (0.047 g) and propargyl bromide (0.081 ml) were added at 0° C. followed by the heating of the reaction mixture at 40-45° C. for 1 hr allowed to reach reaction completion. The reaction mixture was treated with abs. Ethanol (4 ml) and diluted with diethyl ether. The resulting insoluble residue was filtered off and the filtrate was concentrated in vacuo to give 2.89 g of crude residue which was purified by column chromatography (hexane/ethyl acetate 1:1) to yield 2.33 g of 3-Methyl-3prop-2-ynyloxymethyl-1-oxa-4-aza-spiro[4.5]decane as an orange liquid.

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