Ethanol → 2-Isopropylamino-3-hydroxy-5,8-dimethoxy-1,2,3,4-tetrahydronaphthalene

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Reaction Steps

A mixture of 10.3 g of 6,7-epoxy-5,6,7,8-tetrahydro-1,4-dimethoxynaphthalene in 50 ml of isopropylamine containing 2.93 ml of absolute ethanol is heated overnight in a small Parr bomb at 105° C ± 5° C (internal pressure = 75-100 psi). The cooled reaction mixture is concentrated in vacuo to 11.51 g of tan solid. Trituration with ether gives 10.1 g of material, melting point 141-144° C. Two recrystallizations from ethyl acetate give 7.0 g of trans-1,2,3,4-tetrahydro-3-[(1-methylethyl)amino]-5,8-dimethoxy-2-dimethoxy-2-naphthalenol, melting point 144°-145° C.

Provenance & Evidence