Dimethylformamide → HCID 59406942, compound

Participants

Reaction Conditions

Reaction Steps

A solution of 51 ml (128 mmol) of 2.5 N n-butyllithium in hexanes was added slowly to a THF solution of 16 ml (95 mmol) of tetramethylpiperidine cooled in a dry ice-acetone bath. The solution was warmed to −30° C. and cooled to −60° C. before 5.0 g (32 mmol) of 6-chloronicotinic acid was added portion wise. The mixture was warmed to −25° C. and stirred for 30 min. It was then cooled to −70° C. and 10 ml (129 mmol) DMF was added quickly. After quenching with 1N HCl, the solution was warmed to room temperature. The pH was brought to about 4 with additional 1N HCl and the solution was continuously extracted with EtOAc overnight. The EtOAc was dried (MgSO4) and concentrated. The residue was dissolved in 100 ml EtOH and 2 ml concentrated H2SO4 was added. The solution was heated at reflux for 24 h. The mixture was brought to about pH=4 with 50% NaOH and was extracted twice with ether. The ether was dried (MgSO4) and concentrated to gave an oil that was chromatographed on silica gel (50% hexanes in CH2Cl2 with gradient elution to 100% CH2Cl2) to afford 1 g of product as an oil that slowly solidified. NMR (CDCl3): 1.4 (t, 3H), 4.5 (q, 2H), 7.7 (s, 1H), 9.1 (s, 1H), 10.7 (s, 1H).

Provenance & Evidence