N-Iodosuccinimide → 3-Iodo-2,5-dimethyl-7-(pentan-3-yl)pyrazolo[1,5-a]pyrimidine

HRID 1639655Notes

Reaction equation

HRID 1639655 reaction equation
[CH2:1]([CH:3]([C:6]1[N:11]2[N:12]=[C:13]([CH3:15])[CH:14]=[C:10]2[N:9]=[C:8]([CH3:16])[CH:7]=1)[CH2:4][CH3:5])[CH3:2].[I:17]N1C(=O)CCC1=O>C(#N)C.ClCCl>[CH2:1]([CH:3]([C:6]1[N:11]2[N:12]=[C:13]([CH3:15])[C:14]([I:17])=[C:10]2[N:9]=[C:8]([CH3:16])[CH:7]=1)[CH2:4][CH3:5])[CH3:2]

Participants

5

Reactant 2

HCID 120273N-IodosuccinimideHCID 248985207-(1-Ethyl-propyl)-2,5-dimethyl-pyrazolo[1,5-a]pyrimidine

Product 1

HCID 248985233-Iodo-2,5-dimethyl-7-(pentan-3-yl)pyrazolo[1,5-a]pyrimidineYield 97.1%

Reagents, catalysts & solvents 2

HCID 6342AcetonitrileSolvent2×HCID 6344DichloromethaneSolvent

Procedure

Dissolve 7-(1-ethyl-propyl)-2,5-dimethyl-pyrazolo[1,5-a]pyrimidine (2.14 g, 9.84 mmol) in anhydrous acetonitrile (25 mL) and add 6 portions (0.5 g each) of N-iodosuccinimide (3.0 g, 13.3 mmol) at 10 min intervals. Stir the reaction for 4 h. Strip off the acetonitrile and dilute the resulting oil with dichloromethane (100 mL). Wash the orange solution with saturated ammonium chloride solution (2×50 mL). Collect the organic phase, dry over anhydrous magnesium sulfate, filter, and concentrate under reduced pressure to yield a dark red oil. Purify using flash chromatography, eluting with 100% pentane/0% (20% ethyl acetate/pentane) to 0% pentane/100% (20% ethyl acetate/pentane) in a step gradient of 50% increments to give an orange oil (3.28 g, 97%). 1H NMR (400 MHz, CDCl3): 6.44 (s, 1H), 3.59 (m, 1H), 2.61 (s, 3H), 2.49 (s, 3H), 1.86-1.76 (m, 4H), 0.85 (t, J=7.5 Hz, 6H).

Workup

  1. customthe reaction for 4 h
  2. washWash the orange solution with saturated ammonium chloride solution (2×50 mL)
  3. customCollect the organic phase
  4. dry with materialdry over anhydrous magnesium sulfate
  5. filtrationfilter
  6. concentrationconcentrate under reduced pressure
  7. customto yield a dark red oil
  8. customPurify
  9. washeluting with 100% pentane/0% (20% ethyl acetate/pentane) to 0% pentane/100% (20% ethyl acetate/pentane) in a step gradient of 50% increments

Sources & evidence

ORD record
ord-d402d422b32a406993b37cf9035108f4
Source dataset
uspto-grants-2012_02
Patent number
US08110580B2

Reaction notes

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