Sodium hydride → 2-Dimethylamino-5-fluoro-6-methoxybenzo[b]thiophen-3-yl 4-[2-(1-Pyrrolidinyl)ethoxy]phenyl Ketone

Participants

Reaction Steps

A mixture of 2.0 g (5.34 mmol) of 2-dimethylamino-5-fluoro-6-methoxybenzo[b]thiophene-3-yl 4-nitrophenyl ketone (Part C) and 1.4 g (60% dispersion in mineral oil; 35.0 mmol; washed with hexanes) of NaH in 60 mL of DMF was treated with a solution of 3.75 mL (32.1 mmol) of 1-(2-hydroxyethyl)pyrrolidine in 10 mL of DMF in such rate to control the effervescence. After complete addition, the reaction was stirred at room temperature for 1 h and was quenched by the careful addition of 5 mL of MeOH. The mixture was diluted with 200 mL of EtOAc and was poured into 200 mL of H2O. The two layers were separated and the organic phase was washed with H2O (2×100 mL) and brine (100 mL). The organic phase was dried over K2CO3, filtered, and concentrated in vacuo to give 5.21 g of an amber oil. Purification by flash chromatography (SiO2; gradient of 2% then 5% MeOH in CH2Cl2) afforded 2.10 g (4.74 mmol; 89%) of the title compound as a bright yellow oil.

Provenance & Evidence