Thionyl Chloride → methyl 6-(2-(methoxycarbonyl)-1H-pyrrol-1-yl)-5-nitronicotinate

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

Methyl 1H-pyrrole-2-carboxylate (5.78 g, 46.2 mmol) was dissolved in DMSO and cooled to 10° C. NaH was added in two portions over 5 min. The reaction mixture was stirred at 10° C. for 10 min and methyl 6-chloro-5-nitronicotinate (5 g, 23.09 mmol) in DMSO (10 mL) was added slowly over 3 min. The red reaction mixture was allowed to warm to room temperature and stirred overnight. It was cooled to 0° C. and quenched with water (12 mL) and diluted with brine (50 mL). The mixture was washed with EtOAc (2×25 mL) and the aqueous layer was acidified to pH=2 with 4.5 N HCl. It was extracted with EtOAc (1×100 mL) and the organic layer was dried (Na2SO4), filtered and concentrated in vacuo to afford a yellow solid, which was dissolved in MeOH (100 mL) and cooled to 0° C. Thionyl chloride (45 mL, 617 mmol) was added slowly over 5 min. The reaction mixture was stirred at 0° C. for 1 h and then at room temperature overnight. It was concentrated in vacuo and the resulting solid was triturated with ethyl acetate (300 mL). The solid was filtered off and the filtrate was concentrated in vacuo. then washed with ethyl ether to afford methyl 6-(2-(methoxycarbonyl)-1H-pyrrol-1-yl)-5-nitronicotinate (5.04 g, 16.51 mmol, 92% yield) as a yellow solid, [M+H] calc'd for C13H11N3O6, 306; found, 306.

Herkunft & Nachweise