Hydrochloric Acid → 5-Chloro-2-dodecyl-1-naphthalenol

Reaction equation

[Cl:1][C:2]1[CH:11]=[CH:10][CH:9]=[C:8]2[C:3]=1[CH:4]=[CH:5][C:6]([C:13](=O)[CH2:14][CH2:15][CH2:16][CH2:17][CH2:18][CH2:19][CH2:20][CH2:21][CH2:22][CH2:23][CH3:24])=[C:7]2[OH:12].Cl>[Zn].C(O)C>[Cl:1][C:2]1[CH:11]=[CH:10][CH:9]=[C:8]2[C:3]=1[CH:4]=[CH:5][C:6]([CH2:13][CH2:14][CH2:15][CH2:16][CH2:17][CH2:18][CH2:19][CH2:20][CH2:21][CH2:22][CH2:23][CH3:24])=[C:7]2[OH:12]

Participants

Procedure

A solution of 17.4 parts of 1-(5-chloro-1-hydroxynaphthalen-2-yl)-1-dodecanone and 107 parts of 37% hydrochloric acid in 2.5 parts of ethanol was contacted with stirring at reflux during 26 hours, with 40 parts of zinc dust which has been amalgamated by treatment with 3 parts of mercuric chloride and 53 parts of 2.1% hydrochloric acid followed by washing with ethanol. The zinc amalgam was added in small portions throughout the reaction period. Upon cooling, a solid separated. After dissolution of this solid in ethanol, zinc amalgam was filtered, and cooling gave 0.5 parts of starting material which was filtered. Concentration of the filtrate, purification by recrystallization from ethanol, and column chromatography on silica gel using 1-chlorobutane as eluent gave 12 parts of 5-chloro-2-dodecyl-1-naphthalenol, m.p. 68°-70° C.