Dimethylformamide → tert-Butyl 4-carbamoyl-4-isopropylpiperidine-1-carboxylate

To a solution of 1-(tert-butoxycarbonyl)-4-isopropylpiperidine-4-carboxylic acid (500 mg, 1.843 mmol) in dichloromethane (5 ml) were added oxalyl chloride (2.76 ml, 5.53 mmol) and a drop (ca. 10 μl) of dimethylformamide. After stirring 1 h at room temperature, the mixture was concentrated and then dissolved in tetrahydrofuran (5 ml). Concentrated ammonium hydroxide (5 ml, 36.0 mmol) was added and the mixture was stirred overnight at room temperature, and then concentrated to a small volume, poured into 50 ml of 1 M NaOH, and diluted with 50 ml of ethyl acetate. The phases were separated, the aqueous was extracted with 2×25 ml of ethyl acetate, and then the combined organics were washed with 25 ml of brine, dried (Na2SO4), and concentrated to provide the title compound (411 mg, 1.520 mmol, 82% yield). Mass spectrum (ESI) 174.0 (M-Boc).

1. concentrationthe mixture was concentrated
2. dissolutiondissolved in tetrahydrofuran (5 ml)
3. stirringthe mixture was stirred overnight at room temperature
4. concentrationconcentrated to a small volume
5. additionpoured into 50 ml of 1 M NaOH
6. additiondiluted with 50 ml of ethyl acetate
7. customThe phases were separated
8. extractionthe aqueous was extracted with 2×25 ml of ethyl acetate
9. washthe combined organics were washed with 25 ml of brine
10. dry with materialdried (Na2SO4)
11. concentrationconcentrated

ORD record

ord-f1f9fc6b9ff84bd1a4a655c0a4f40292

Source dataset

uspto-grants-2013_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08445480B2