Acetone → (R)-3-(N-Isopropylamino)-5-methoxychroman

Participants

Reaction Steps

(R)-3-Amino-5-methoxychroman (1.0 g; 6 mmol) and acetone (2.5 g; 40 mmol) were mixed with methanol (820 ml), acetic acid (0.4 g; 6.6 mmol) and NaCNBH3 (1.2 g; 19 mmol), pH was adjusted to 6.0 with acetic acid. Stirring was continued at room temperature for 3 days. The mixture was evaporated and the residue was made alkaline and extracted with CH2Cl2. After drying (Na2SO4) and evaporation the title compound as base was transformed to the HCl-salt. Yield: 1.1 g (83%). Mp: 289° dec. [α]D25 =-29° (C=0.015; MeOH)

Provenance & Evidence