Acetic Acid → ((1RS,2SR)-2-Cyclopentylamino-cyclopentyl)-carbamic acid tert-butyl ester

HRID 659208Notes

Reaction equation

HRID 659208 reaction equation
[CH3:1][C:2]([O:5][C:6](=[O:14])[NH:7][CH:8]1[CH2:12][CH2:11][CH2:10][CH:9]1[NH2:13])([CH3:4])[CH3:3].C(O)(=O)C.[C:19]1(=O)[CH2:23][CH2:22][CH2:21][CH2:20]1.C([BH3-])#N.[Na+]>CO>[C:2]([O:5][C:6](=[O:14])[NH:7][CH:8]1[CH2:12][CH2:11][CH2:10][CH:9]1[NH:13][CH:19]1[CH2:23][CH2:22][CH2:21][CH2:20]1)([CH3:1])([CH3:3])[CH3:4]

Participants

6

Reactant 4

HCID 176Acetic AcidHCID 8452CyclopentanoneHCID 5003444Sodium cyanoborohydrideHCID 22667934tert-Butyl (2-aminocyclopentyl)carbamate

Product 1

HCID 66682614((1RS,2SR)-2-Cyclopentylamino-cyclopentyl)-carbamic acid tert-butyl esterYield 58.2%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Conditions

Temperature
50 °C

Procedure

To a solution of [(1RS,2SR)-2-aminocyclopentyl-carbamic acid 1,1-dimethylethyl ester (CAS 365996-19-6) (500 mg, 2.497 mmol) in 10 ml methanol was added acetic acid (0.714 ml, 12.49 mmol) and cyclopentanone (0.665 ml, 7.491 mmol). The mixture was heated in a 50° C. oil bath for 1.5 hour. The solution was cooled to room temperature and sodium cyanoborohydride (370 mg, 5.0 mmol) was added portionwise. The mixture was heated in a 50° C. oil bath for 2.5 hours. The solution was cooled in an ice bath and quenched by dropwise addition of 6 ml 2N NaOH. The methanol was removed in vacuo. The aqueous layer was diluted with water and extracted 3 times with ethyl acetate. The combined extracts were dried over Na2SO4, filtered and concentrated in vacuo. The crude oil was purified on silica gel (eluent: heptane/ethyl acetate 0 to 100%) to provide 0.39 g (58%) of the title compound as a light brown solid. MS (m/e): 269.3 (M+H).

Workup

  1. temperatureThe solution was cooled to room temperature
  2. temperatureThe mixture was heated in a 50° C. oil bath for 2.5 hours
  3. temperatureThe solution was cooled in an ice bath
  4. customquenched by dropwise addition of 6 ml 2N NaOH
  5. customThe methanol was removed in vacuo
  6. additionThe aqueous layer was diluted with water
  7. extractionextracted 3 times with ethyl acetate
  8. dry with materialThe combined extracts were dried over Na2SO4
  9. filtrationfiltered
  10. concentrationconcentrated in vacuo
  11. customThe crude oil was purified on silica gel (eluent: heptane/ethyl acetate 0 to 100%)

Sources & evidence

ORD record
ord-f4fc23972292422ba494bba838492b17
Source dataset
uspto-grants-2011_12
Patent number
US08080541B2

Reaction notes

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