Brief introduction of

Electric Literature of 234108-73-7 , The common heterocyclic compound, 234108-73-7, name is tert-Butyl 2-chloropyridine-4-carbamate, molecular formula is C10H13ClN2O2, its traditional synthetic route has been very mature, but the traditional synthetic route has various shortcomings, such as complicated route, low yield, poor purity, etc., below Introduce a new synthetic route.

A solution of 4-amino-2-chloropyridine (1.28 gm, 10 mmol) and di-tert-butyl dicarbonate (2.21 gm, 10.1 mmol) in THF (20 mL) was cooled to 00C and a solution of IM lithium bis(trimethylsilyl)amide in THF ( 20 mL, 20 mmol) was added slowly maintaining the temperature below 00C. The reaction was allowed to warm to room temperature over one hour and then quenched by the addition of 1.5 N aqueous ammonium chloride (15 mL). After stirring for several hours the reaction was extracted into ethyl acetate, washed with brine, the organic layer dried (Na2SO4), filtered and evaporated. The residue was triturated with diethyl ether give pure tert-butyl (2-chloropyridin-4- yl)carbamate. The mother liquors were chromatographed on silica gel eluting with 25 – 45% ethyl acetate/ hexane to afford more product. EPO A solution of tert-butyl (2-chloropyridin-4-yl)carbamate (1.14 gm, 5 mmol) in dry THF (20 mL) was cooled to -700C under an inert atmosphere and 1.7 M t-butyl lithium/pentane (8 mL, 13.5 mmol) was slowly added. The reaction was stirred for two hours and then dry DMF (1.2 mL, 15.5 mmol) was added. The reaction was allowed to slowly warm to room temperature over a three hour period. The reaction mixture was quenched with 3 N HCl (12 mL) and diluted with diethyl ether. The ether layer was washed with aqueous NaHCtheta3, dried (over Na2SO4), filtered and evaporated. The residue was triturated with cold diethyl ether to give pure t-butyl (2-chloro-3-formylrhoyridin-4- yl)carbamate. The mother liquors were chromatographed on silica gel eluting with 15-20% ethyl acetate/hexane to give additional product. 1H-NMR(5OO MHz, CDCI3): deltall.O (IH, br s), 10.52 (IH, s), 8.38 (IH, d, J= 6 Hz), 8.31 (IH, d, J= 6 Hz), 1.54 (9H, s); m/e (m+1): 257.2.

The synthetic route of 234108-73-7 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; MERCK & CO., INC.; WO2006/135627; (2006); A2;,
Pyridine – Wikipedia,
Pyridine | C5H5N – PubChem