Formaldehyde → HCID 69498082, compound

Participants

Reaction Steps

To a suspension of 0.50 g (0.89 mmol) of (2′S,3′R,4′S,5′R)-6-chloro-4′-(3-chloro-2-fluoro-phenyl)-2′-(2,2-dimethyl-propyl)-2-oxo-1,2-dihydro-spiro[indole-3,3′-pyrrolidine]-5′-carboxylic acid (trans-4-hydroxy-cyclohexyl)-amide in 18.0 mL of acetonitrile under argon, were added 0.89 mL (0.97 mmol) of a 36.5% solution of formaldehyde in water, followed by 65 mg (0.98 mmol) of sodium cyanoborohydride. The resulting solution was stirred at room temperature for 2 hours, upon which it was poured into 50 mL of ethyl acetate. The aqueous phase was separated and the organic phase was washed with a saturated solution of sodium hydrogencarbonate. The latter aqueous phase was reextracted with ethyl acetate. The combined organic extracts were washed with brine, dried with magnesium sulfate and then concentrated to dryness under reduced pressure. The residue (0.52 g) was purified by chiral HPLC chromatography on a Kromasil C18 column (1100 g batch 4680, 10 μm, 7.65×35 cm), eluting solvent: acetonitrile/water 40/60 v/v+0.1% trifluoroacetic acid; flow: 250 mL/min. The collected solution was treated with sodium hydrogencarbonate up to pH 8 and then extracted 3 times with 200 mL of ethyl acetate. The combined organic extracts were washed twice with 100 mL of water, dried with magnesium sulfate and then concentrated to dryness under reduced pressure. The residue was then dried in a dessicator under reduced pressure for 16 hours. 0.17 g of (2′S,3′R,4′S,5′R)-6-chloro-4′-(3-chloro-2-fluoro-phenyl)-2′-(2,2-dimethyl-propyl)-1′-methyl-2-oxo-1,2-dihydro-spiro[indole-3,3′-pyrrolidine]-5′-carboxylic acid (4-hydroxy-cyclohexyl)-amide was obtained as a white solid. mp: 188° C. (Kofler); LC-MS:

Provenance & Evidence