Reaction #57464

Reaction equation

tert-butyl N-[(1S,2R)-1-benzyl-4-(cyclopentyloxy)-2-hydroxy-4-(6-quinoxalinylsulfonyl)butyl]carbamate

trifluoroacetic acid

→

(3R,4S)-4-amino-1-(cyclopentyloxy)-5-phenyl-1-(6-quinoxalinylsulfonyl)-3-pentanol

Yield 82.4%

Conditions

Workup

1. 1
   OtherThe acid was removed in vacuo
2. 2
   Otherthe residue was partitioned between dichloromethane and 1N sodium hydroxide
3. 3
   OtherThe organic layer was separated
4. 4
   Extractionthe aqueous layer was extracted again with dichloromethane
5. 5
   DryingThe combined organic layers were dried over anhydrous sodium sulfate
6. 6
   Filtrationfiltered
7. 7
   Otherevaporated in vacuo
8. 8
   OtherThe crude product was purified on flash grade silica gel eluting with dichloromethane:methanol (98:2)
9. 9
   workup.ADDITIONFractions containing the product
10. 10
    Otherevaporated in vacuo
11. 11
    Otherdried under high vacuum

Procedure

A mixture of tert-butyl N-[(1S,2R)-1-benzyl-4-(cyclopentyloxy)-2-hydroxy-4-(6-quinoxalinylsulfonyl)butyl]carbamate (563 mg, 1.01 mmol) and trifluoroacetic acid (5 mL) was stirred under an Argon atmosphere for 0.5 hrs. The acid was removed in vacuo and the residue was partitioned between dichloromethane and 1N sodium hydroxide. The organic layer was separated and the aqueous layer was extracted again with dichloromethane. The combined organic layers were dried over anhydrous sodium sulfate, filtered and evaporated in vacuo. The crude product was purified on flash grade silica gel eluting with dichloromethane:methanol (98:2). Fractions containing the product were combined and evaporated in vacuo and dried under high vacuum to provide (3R,4S)-4-amino-1-(cyclopentyloxy)-5-phenyl-1-(6-quinoxalinylsulfonyl)-3-pentanol as a foam (379 mg, 82%). H1-NMR (chloroform-D3): 1.66 (m, 11H), 2.51 (m, 1H), 2.86 (m, 1H), 3.07 (m, 1H), 3.23 (m, 1H), 3.32 (m, 1H), 3.84 (m, 1H), 4.90 (m, 1H), 7.20 (m, 5H), 8.16 (m, 1H), 8.28 (d, 1H), 8.70 (m, 1H), 8.99 (m, 2H). MS (ESI): 457 (M+H).

Source