Hydrochloric Acid → Triphenylene-2-carbaldehyde

Participants

Reaction Steps

A 1 L 3-neck flask fitted with overhead mechanical stirrer, thermometer, condenser, and N2 line was charged with triphenylene (Aldrich Chemical Co., Milwaukee, WI, 53201, 30 g, 0.131 mol) and o-dichlorobenzene (150 mL). The liquid was warmed until all the large chunks of solid dissolved (80°) and then cooled quickly to give finely divided crystals. After further cooling with a salt-ice bath to 5°, SnCl4 (Aldrich, 98%, 58 g, 0.223 mol, 26 mL), was added in one portion to the mixture. No temperature change occurred. The pot temperature was kept below 5°, and 1,1-dichloromethylmethylether (Aldrich, 25.6 g, 0.223 mol, 20 mL) was added dropwise over 1 h. The resulting suspension was warmed slowly to 40° over 2 h and further stirred for 16 h. Considerable HCl gas evolution occurred during the warming and the early part of the reaction at 40°. The reaction mixture was then cooled to 10° and hydrolysed by careful addition of 1 L of cold H2O. After 4 h the layers were separated and the organic layer filtered, dried with anhydrous Na2SO4 (Mallinckrodt Co., 2nd and Mallinckrodt St., St. Louis, MO, 63147, 100 g) and filtered again. The solvent was removed to give a crude yellow oil which was purified by preparative HPLC using PhCH3 as the eluting solvent. The fractions containing the aldehyde were combined and the solvent removed to give an oil which solidified (8.31 g, 25%). This material was used without further purification. Recrystallization from CH2Cl2 /CH3OH gave pure 2-triphenylenecarbaldehyde mp 160°-161.5°, (C,H).

Provenance & Evidence