Efficient resolution of (±)-1-(9-anthryl)ethylamine

Conditions for efficient resolution of (+/-)-1-(9-anthryl)ethylamine (+/--1) by fractional crystallization of its salts with (S)-(+)-mandelic acid (2) are reported. When crystallization was performed by fast addition of chloroform solution of an equivalent of (+/-)-1 to the hot chloroform solution of (+)-2, crystals of mandelate of (+)-1-(9-anthryl)ethylamine ((R,S)-3) are collected in 56% yield. (R)-(+)-1 (98.6% e.e.) is isolated by extraction from bicarbonate solution of mandelate salt. Ulterior collection of four crops afforded (R,S)-3 with 71.5% cumulative yield and >98% e.e. of (+)-1 in a any single crop. With only 0.5 equivalents of (+)-2 crystallization afforded (R,S)-3 in 47.4% yield and (+)-1 with 98.1% e.e.