From pihkal, 2C-G-N entry:
SYNTHESIS: A solution of 17.5 g 1,4-naphthaquinone in 200 mL MeOH was heated to the boiling point, and treated with 28.5 g stannous chloride at a rate that maintained a continuous rolling boil. At the completion of the addition, the reaction mixture was saturated with anhydrous hydrogen chloride, and held at reflux on the steam bath for 2 h. The reaction mixture was poured into 700 mL H2O and treated with aqueous NaOH. During the addition there was transient development of a curdy white solid which redissolved when the system became strongly basic. This was extracted with 3x200 mL CH2Cl2 and the pooled extracts were washed first with H2O, then with dilute HCl, and finally again with H2O. Removal of the solvent under vacuum yielded 15.75 g of a low melting black flaky crystalline material which was distilled at 160-180 °C at 0.05 mm/Hg to give 14.5 g of an amber, solid mass with a mp of 78-86 °C. Recrystallization from 75 mL boiling MeOH provided 1,4-dimethoxynaphthalene as white crystals melting at 87-88 °C.
This look like a reductive methylation of quinone without methylating agent (DMS,CH3I...) like what Antoncho searched months ago. Do some bee know this reaction? Could it bee aplied with an amine in solution or will reductive amination occur?I guess it form the diacetal of the quinone which is reducted by Sn after it's formation but really i dont know