(3R)-1,1,3-trimethyl-2,3-dihydro-1H-inden-4-amine → 1,1,3-Trimethylindan-4-amine

Into a reaction vessel were charged 31.7 parts by weight of (3R)-1,1,3-trimethyl-4-aminoindane (optical purity of 67.0% ee) and 0.76 parts by weight of 5% palladium-carbon (E-type, manufactured by N. E. Chemcat Corporation), thereby obtaining a mixture. The reaction vessel was sealed and the gas in the reaction vessel was replaced with nitrogen. While the mixture was stirred, into the reaction vessel was charged hydrogen until the internal pressure of hydrogen in the reaction vessel reached 0.5 MPa, and the mixture was stirred at an internal temperature of 60° C. After 1 hour, the gas in the reaction vessel was replaced with nitrogen, and the mixture was stirred at an internal temperature of 145° C. and an internal pressure of 0.15 MPa for 14 hours, thereby obtaining a reaction mixture. The obtained reaction mixture was cooled and filtered. The obtained solid was washed with 45 parts by weight of toluene. The washing liquid recovered after washing and the filtrate obtained by filtration were combined to obtain a solution of 73.0 parts by weight of 1,1,3-trimethyl-4-aminoindane in toluene. The combined 1,1,3-trimethyl-4-aminoindane had an optical purity of 0.7% ee and a recovery rate of 97.7%.