Hydrochloric Acid → Ethyl (3S,4R)-4-{[(3,4-dichloro-5-methyl-1H-pyrrol-2-yl)carbonyl]amino}-3-(prop-2-en-1-yloxy)piperidine-1-carboxylate

To a solution of 3,4-dichloro-5-methyl-1H-pyrrole-2-carboxylic acid (WO200687543, 2.27 g, 11.8 mmol) and Ethyl (3S,4R)-4-amino-3-(prop-2-en-1-yloxy)piperidine-1-carboxylate (Intermediate 18, 2.7 g, 11.8 mmol) in dichloromethane (180 mL) was added HOBt (1.85 g, 11.8 mM) and N-methylmorpholine (3.8 mL, 35.43 mmol). The reaction mixture was stirred for 1 h at room temperature and EDC HCl (4.07 g, 21.3 mmol) was added. The resulting reaction mixture was stirred for room temperature overnight, treated by the addition of 2 N HCl (120 mL) and the resulting layers were evaporated. The organic layer was washed with sodium bicarbonate (150 mL), water (150 mL) and brine, dried over anhydrous sodium sulphate, filtered, concentrated under vacuum. Purification by column chromatography (silica gel, 35% ethylacetate in pet ether) to afforded 3.5 g (73.6%) as brown solid. NMR (400 MHz, DMSO-d6): δ 1.24 (t, 3H), 1.62 (m, 2H), 2.16 (s, 3H), 2.97 (m, 2H), 3.53 (m, 2H), 3.97 (m, 4H), 4.15 (q, 2H), 4.21 (m, 1H), 5.13 (d, 1H), 5.23 (d, 1H), 5.87 (m, 1H), 7.10 (d, 1H), 12.10 (s, 1H).

1. customThe resulting reaction mixture
2. stirringwas stirred for room temperature overnight
3. customthe resulting layers were evaporated
4. washThe organic layer was washed with sodium bicarbonate (150 mL), water (150 mL) and brine
5. dry with materialdried over anhydrous sodium sulphate
6. filtrationfiltered
7. concentrationconcentrated under vacuum
8. customPurification by column chromatography (silica gel, 35% ethylacetate in pet ether)
9. customto afforded 3.5 g (73.6%) as brown solid

ORD record

ord-373d2cb8a55349afbf4d43a684dd2027

Source dataset

uspto-grants-2011_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08071605B2