4-(Cyclohexylmethylamino)-1,2-naphthoquinone → 1,2-Naphthalenediol, 4-(cyclohexylmethylamino)-, 1,2-diacetate

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Reaction Steps

A suspension of 3.5 g of 4-(N-methylcyclohexylamino)-1,2-naphthoquinone in 50 ml of acetic anhydride is hydrogenated at 45 lbs pressure and room temperature using 1.2 g of 10% palladium on carbon as catalyst. After uptake of hydrogen ceases and the red color of the solution is discharged (5 hours) the catalyst is removed by filtration. The acetic anhydride is evaporated under reduced pressure at 60° C. and the residue is taken up in toluene, treated with charcoal and filtered. The toluene solution is evaporated under reduced pressure and the product crystallized from 1:1 hexane-diethyl ether (100 ml) to afford 4-(N-methylcyclohexylamino)-1,2-diacetoxynaphthalene, the compound of formula II wherein NR1R2 represents N-methylcyclohexylamino, R3 represents hydrogen, and R4 and R5 represent acetyl, m.p. 103°-105° C.; hydrochloride salt, m.p. 165°-167° C.

Provenance & Evidence