Sulfuric Acid → Trans-3-azido-1,2,3,4-tetrahydro-5-methoxy-2-naphthalinol

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Reaction Steps

30.0 g (0.170M) of 1a,2,7,7a-tetrahydro-3-methoxynaphth[2,3-b]oxirane are dissolved in dimethyl sulphoxide. Furthermore, 90.0 g (1.384M) of sodium azide are suspended in DMSO and 19.5 g (0.200M) of concentrated sulphuric acid are dissolved in DMSO. The total quantity of DMSO is 1000 ml. The solutions and supensions are combined. Stirring subsequently takes place for 15 hours at 60°. 1500 ml of methylene chloride are then added to the reaction mixture. A suspension is obtained, which is filtered over Hyflo. The rose solution is concentrated by evaporation at 60° (10 torr), then at 80° (high vacuum 1/100 torr). Trans-3-azido-1,2,3,4-tetrahydro-5-methoxy-2-naphthalinol (m.p. 83°-84°) and its structural isomer trans-3-azido-1,2,3,4-tetrahydro-8-methoxy-2-naphthalinol (m.p. 145°-147°) are obtained in a ratio of 1:1. The structural isomers are separated by fractional crystallisation (methylene chloride/hexane).

Provenance & Evidence