Step 7-2: 1.18 g of (R)-1-(tert-butoxycarbonyl)-3-methylaminopyrrolidine hydrochloride (chemical purity: 99.9 area%) was mixed with 2.30 g of 23 wt. % brine, 4.71 g of toluene and 734 mg of 30 wt. % aqueous sodium hydroxide solution, and was prepared in accordance with the methodology described in Step 7-1. After stirring the reaction mixture, a partitioning operation was carried out. The organic layer was concentrated and dried under vacuum to give 946 mg of tert-butyl (R)-3-(methylamino)pyrrolidine-1-carboxylate as a colorless, transparent liquid (chemical purity: 99.3 area%, yield 97%).1H-NMR (CDCl3) data: δ (ppm) 1.45 (s, 9H), 1.71 (m, 2H), 2.04 (m, 1H). 2.44 (s, 3H), 3.03-3.28 (m, 2H), 3.29-3.65 (m, 3H).
