Hydrochloric Acid → HCID 45789215, compound

Participants

Reaction Steps

To a solution of 4-amino-3-chloropyridine (15 g, 116.7 mmol) in THF (60 mL) is added NaHMDS in THF (1 M, 233. mL, 233 mmol). After stirring at rt for 30 min, BOC20 (23.2 g, 106 mmol) in THF (45 mL) is added in one portion and the mixture is stirred for 3 h at rt. Additional BOC2O (2 g, 9.0 mmol) in THF (40 mL) is added and the reaction is stirred for 18 h at rt. 0.1% aqueous HCl (1.35 L) is added. The mixture is extracted with EtOAc. The organic layer is dried (Na2SO4), filtered and concentrated. The residue is recrystallized from ether to afford (3-chloro-pyridin-4-yl)-carbamic acid tert-butyl ester (4 g). The mother liquor is purified by silica gel column chromatography eluting with 0-50% EtOAc in heptane. The collected product is crystallized from ether to afford additional 4.5 g of (3-chloro-pyridin-4-yl)-carbamic acid tert-butyl ester (total yield 8.5 g). MS: 229 (M+H); 1H NMR (300 MHz, CDCl3): δ 8.48 (s, 1H), 8.38 (d, 1H), 8.17 (d, 1H), 7.18 (broad s, 1H) 1.57 (s, 9H).

Provenance & Evidence