Acetic Acid → (R)-3-(N-cyclopentylamino)-8-fluoro-5-methoxy-3,4-dihydro-2H-1-benzopyran

HRID 52285Notes

Reaction equation

HRID 52285 reaction equation
[NH2:1][C@@H:2]1[CH2:7][C:6]2[C:8]([O:13][CH3:14])=[CH:9][CH:10]=[C:11]([F:12])[C:5]=2[O:4][CH2:3]1.[C:15]1(=O)[CH2:19][CH2:18][CH2:17][CH2:16]1.CC(O)=O.[BH3-]C#N.[Na+]>CO>[CH:15]1([NH:1][C@@H:2]2[CH2:7][C:6]3[C:8]([O:13][CH3:14])=[CH:9][CH:10]=[C:11]([F:12])[C:5]=3[O:4][CH2:3]2)[CH2:19][CH2:18][CH2:17][CH2:16]1

Participants

6

Reactant 4

HCID 176Acetic AcidHCID 8452CyclopentanoneHCID 5003444Sodium cyanoborohydrideHCID 22871215(R)-8-fluoro-5-methoxy-3-aminochroman

Product 1

HCID 22871220(R)-3-(N-cyclopentylamino)-8-fluoro-5-methoxy-3,4-dihydro-2H-1-benzopyranYield 100%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

To a solution of (R)-3-amino-8-fluoro-5-methoxy-3,4-dihydro-2H-1-benzopyran (0.7 g, 3.4 mmol), cyclopentanone (0.7 g, 8.3 mmol) and HOAc (0.2 g, 3.5 mmol) in methanol (25 mL), NaCNBH3 (0.7 g, 10 mmol) was added in portions at room temperature. The solution was stirred at room temperature over night. The methanol was evaporated. The residue was dissolved in EtOAc and washed with water. The organic layer was dried with Na2SO4 and the solvent was evaporated to give 0.9 g (100% yield) of the title compound as a colourless oil. GC indicated 99.6 purity. GC/MS (70 eV) M=265 (30%).

Workup

  1. customThe methanol was evaporated
  2. dissolutionThe residue was dissolved in EtOAc
  3. washwashed with water
  4. dry with materialThe organic layer was dried with Na2SO4
  5. customthe solvent was evaporated

Sources & evidence

ORD record
ord-56cf6baf404b44228754487eeee27db1
Source dataset
uspto-grants-1997_04
Patent number
US05616610

Reaction notes

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