Formaldehyde → 3-{(2S,4S)-1-tert-butoxycarbonyl-4-[N-(4-cyanophenylmethyl)-N-methylamino]-2-pyrrolidinylcarbonyl}-1,3-thiazolidine

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Reaction Steps

3-[(2S,4S)-1-tert-Butoxycarbonyl-4-(4-cyanophenylmethyl)amino-2-pyrrolidinylcarbonyl]-1,3-thiazolidine [product of Example 63 (1), 1.35 g] and 37% formaldehyde solution (0.788 mL) were dissolved in acetonitrile (20 mL), and the mixture was stirred at room temperature for 30 min. Sodium cyanoborohydride (0.305 g) and several drops of acetic acid were added to the reaction mixture, and the reaction mixture was stirred for 1 hr. The reaction mixture was evaporated under reduced pressure. Saturated aqueous sodium hydrogencarbonate solution was added to the residue and the mixture was extracted with ethyl acetate. The extract was dried and the solvent was evaporated under reduced pressure. The residue was purified by silica gel chromatography to give 3-{(2S,4S)-1-tert-butoxycarbonyl-4-[N-(4-cyanophenylmethyl)-N-methylamino]-2-pyrrolidinylcarbonyl}-1,3-thiazolidine (0.953 g) as white amorphous.

Provenance & Evidence