Hydrochloric Acid → HCID 53374160, compound

Participants

Reaction Steps

To the vial containing crude (R)-tert-butyl 5-(1-(benzothiophene-2-carboxamido)ethyl)thiophene-2-carboxylate from Step 2 was added DCM (4 mL) and trifluoroacetic acid (0.43 mL, 5.6 mmol). The mixture was stirred at rt for 16 h and then completely evaporated to give an oil residue. To the residue was added HATU (0.160 g, 0.42 mmol), triethylamine (0.39 mL, 2.80 mmol), and DCM (4 mL). After stirring at rt for 30 min, O-(tert-butyldimethylsilyl)hydroxylamine (0.083 g, 0.56 mmol) was added. The mixture was stirred at rt for 2 h then the solvent was completely removed to give a sticky brown oil. To this oil residue was added hydrochloric acid (6.0 mL, 1% v/v in IPA). After stirring at rt for 30 min, the mixture was evaporated to dryness to give a solid to which was added DMSO (1.1 mL). The solution was filtered and purified by Gilson prep-HPLC [25-50% MeCN—H2O] to give the title compound (0.0098 g, 10.1%) as a white solid. LC-MS: (FA) ES+ 347; 1H NMR (Methanol-d4, 400 MHz) δ 8.00 (s, 1H), 7.89 (m, 2H), 7.42 (m, 3H), 7.06 (d, J=4.0 Hz, 1H), 5.51 (q, J=7.5 Hz, 1H), 1.69 (d, J=7.0 Hz, 3H).

Provenance & Evidence