Hydrochloric Acid → HCID 45789215, compound

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).

1. stirringthe mixture is stirred for 3 h at rt
2. stirringthe reaction is stirred for 18 h at rt
3. extractionThe mixture is extracted with EtOAc
4. dry with materialThe organic layer is dried (Na2SO4)
5. filtrationfiltered
6. concentrationconcentrated
7. customThe residue is recrystallized from ether

ORD record

ord-4d6394a28b3440abb8a7c68fdb07bb54

Source dataset

uspto-grants-2012_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08258130B2