Hydrochloric Acid → 2-((6-Chrysenylmethyl)amino)-2-methyl-1,3-propanediol hydrochloride

Participants

Reaction Steps

To a 2 L Erlenmeyer flask was added 6-chrysenecarbaldehyde (21.2 g, 82.7 mmol), 2-amino-2-methyl-1,3-propanediol (Aldrich, 9.13 g, 86.8 mmol), p-toluenesulfonic acid.H2O (Eastment, 0.5 g, 2.5 mmol), and PhCH3 (500 mL). The mixture was warmed to reflux for a few minutes and H2O (2-3 mL) was driven off. The resulting golden colored solution was allowed to cool to RT, diluted with abs. EtOH (500 mL) and stirred overnight. NaBH3CN (Aldrich, 95%, 2.51 g, 42 mmol) was added to the reaction. After the NaBH3CN dissolved, an indicator (bromocresol green, Eastman, 5 mg) was added. To the resulting blue solution was added 5 drops of 1M ethanolic HCl every 15 min. After 3 days the indicator turned green then yellow and a voluminous white precipitate was present in the flask. To the flask was then added 1M ethanolic HCl (10 mL). The reaction was diluted to 4 L with abs. Et2O and stirred for 1 h. The precipitate was then filtered through a medium porosity glass fritted funnel and pressed dry. The filter cake was washed thoroughly with 20% HCl (5×250 mL), pressed dry and then washed with CH2Cl2 (4×500 mL), pressed and sucked dry. The solid was dissolved in abs. EtOH (1400 mL). 1M ethanolic HCl (1 mL) and 5 g of Calgon® (a trademark of Calgon Corporation, a subsidiary of Merck and Co., Pittsburgh, PA, 15230) brand of activated charcoal were added, and the mixture boiled and filtered through a pad of Celite® (a trademark of Johns Manville Co., P. O. Box 5108, Denver, CO, 80217) brand of filtered aid. The clear yellow solution was concentrated to 500 mL and diluted to 2 L with abs. Et2O which was then filtered to give the crude product. Further crystallization (2x) from CH3OH/Et2O (1:3) gave 18.07 g (57.2%) of 2-((6-chrysenylmethyl)amino)-2-methyl-1,3-propanediol hydrochloride mp 241°-243° (dec), (C,H,Cl,N).

Provenance & Evidence