Benzyl chloroformate → N-Carbobenzoxy-1,5-diaminopentane hydrochloride

To a suspension of 1,5-diaminopentane dihydrochloride (2.9 g, 16.7 mmol) in THF (100 mL) was added 20% aqueous sodium hydroxide (10.0 g, 50 mmol) at 0° C. A solution of benzyl chloroformate (1.7 g, 10 mmol) in THF (10 mL) was added rapidly dropwise and the resulting mixture stirred at RT. After 1 h, the organic layer was separated and concentrated to give a residue which was dissolved in ethyl acetate (200 mL). This solution was extracted with water (3×50 mL.), dried (sodium sulfate) and concentrated. The residue was redissolved in ether (50 mL) and 1.0 ethereal hydrogen chloride (3.0 mL) was added. The resulting precipitate was filtered, suspended in CH2Cl2 (75 mL) and shaken with 5% sodium hydroxide (15 mL). The organic layer was washed with water (75 mL), dried (sodium sulfate) and concentrated to give the title compound 0.25 g, 30%): 1H NMR (400 MHz, CDCl3) δ7.15-7.4 (m, 5H), 5.15-5.4 (m, 1H), 5.05 (s, 2H), 3.05-3.2 (m, 2H), 2.55-2.7 (m, 2H), 1.2-1.5 (m, 6H).

1. customthe organic layer was separated
2. concentrationconcentrated
3. customto give a residue which
4. extractionThis solution was extracted with water (3×50 mL.)
5. dry with materialdried (sodium sulfate)
6. concentrationconcentrated
7. dissolutionThe residue was redissolved in ether (50 mL)
8. addition1.0 ethereal hydrogen chloride (3.0 mL) was added
9. filtrationThe resulting precipitate was filtered
10. stirringshaken with 5% sodium hydroxide (15 mL)
11. washThe organic layer was washed with water (75 mL)
12. dry with materialdried (sodium sulfate)
13. concentrationconcentrated

ORD record

ord-3fcbc75591be42b0b4653cc77002cf96

Source dataset

uspto-grants-2002_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06403578B1