Sulfuric acid magnesium salt (1:1) → 4-[(Benzofuran-6-ylmethyl)-amino]-butyric acid ethyl ester

Participants

Reaction Conditions

Reaction Steps

To a solution of 4-amino-butyric acid ethyl ester hydrochloride (1 eq.) in THF was added TEA (2.5 eq.). The mixture was stirred 5 min at 20° C., then benzofuran-6-carbaldehyde (0.95 eq.) and MgSO4 (3 eq.) were added. The reaction was refluxed for 2 h, then cooled to 20° C. and filtered. The filtrate was added to a suspension of NaBH4 (2 to 6 eq.) in MeOH at −15° C. The reaction was stirred for 2 h at −15° C. The reaction was quenched with the addition of aqueous HCl 2N until pH=2. The aqueous layer was washed twice with EtOAc. The organic layers were discarded. Solid KOH was added to the aqueous layer. The crude was extracted three times with EtOAc. The organic layers were combined, dried over MgSO4, filtered and concentrated under reduced pressure at 20° C. The crude was purified by chromatography on silica gel (elution with DCM/MeOH: 95/5) to afford 4-[(benzofuran-6-ylmethyl)-amino]-butyric acid ethyl ester.

Provenance & Evidence