Perchloric Acid → (S)-methyl 2-(2-(3-bromophenyl)-7-iodo-5-methylpyrazolo[1,5-a]pyrimidin-6-yl)-2-(tert-butoxy)acetate

HRID 1400693Notes

Reaction equation

HRID 1400693 reaction equation
[Br:1][C:2]1[CH:3]=[C:4]([C:8]2[CH:24]=[C:11]3[N:12]=[C:13]([CH3:23])[C:14]([C@H:17]([OH:22])[C:18]([O:20][CH3:21])=[O:19])=[C:15]([I:16])[N:10]3[N:9]=2)[CH:5]=[CH:6][CH:7]=1.Cl(O)(=O)(=O)=O>C(Cl)Cl.C(OC(C)(C)C)(=O)C>[Br:1][C:2]1[CH:3]=[C:4]([C:8]2[CH:24]=[C:11]3[N:12]=[C:13]([CH3:23])[C:14]([C@H:17]([O:22][C:4]([CH3:8])([CH3:5])[CH3:3])[C:18]([O:20][CH3:21])=[O:19])=[C:15]([I:16])[N:10]3[N:9]=2)[CH:5]=[CH:6][CH:7]=1

Participants

5

Reactant 2

HCID 24247Perchloric AcidHCID 86710745(S)-methyl 2-(2-(3-bromophenyl)-7-iodo-5-methylpyrazolo[1,5-a]pyrimidin-6-yl)-2-hydroxyacetate

Product 1

HCID 86710746(S)-methyl 2-(2-(3-bromophenyl)-7-iodo-5-methylpyrazolo[1,5-a]pyrimidin-6-yl)-2-(tert-butoxy)acetateYield 143.9%

Reagents, catalysts & solvents 2

HCID 6344DichloromethaneSolvent2×HCID 10908tert-Butyl acetateSolvent

Procedure

To a stirred solution of (S)-methyl 2-(2-(3-bromophenyl)-7-iodo-5-methylpyrazolo[1,5-a]pyrimidin-6-yl)-2-hydroxyacetate (1 g, 1.992 mmol) in CH2Cl2 (30 mL) and t-butyl acetate (21.00 mL) at rt was added 70% perchloric acid (0.513 mL, 5.97 mmol). After 3 h, the reaction mixture was diluted with CH2Cl2 (100 mL), carefully quenched with sat. NaHCO3 (50 mL), organic layer separated and washed with brine (100 mL), dried (Na2SO4), filtered and concentrated to give yellow liquid. This was purified by flash column chromatograpgy on silica gel column using (10-50% EtOAc/Hex as eluant) to afford (S)-methyl 2-(2-(3-bromophenyl)-7-iodo-5-methylpyrazolo[1,5-a]pyrimidin-6-yl)-2-(tert-butoxy)acetate (800 mg, 1.433 mmol, 72.0% yield) as yellow solid. 1H NMR (500 MHz, CDCl3) δ: 8.20 (s, 1H), 7.95 (d, J=7.7 Hz, 1H), 7.56 (d, J=7.9 Hz, 1H), 7.37 (t, J=7.9 Hz, 1H), 7.08 (s, 1H), 5.59 (s, 1H), 3.76 (s, 3H), 2.70 (s, 3H), 1.32 (s, 9H). LCMS (M+H)=560.15.

Workup

  1. customcarefully quenched with sat. NaHCO3 (50 mL), organic layer
  2. customseparated
  3. washwashed with brine (100 mL)
  4. dry with materialdried (Na2SO4)
  5. filtrationfiltered
  6. concentrationconcentrated
  7. customto give yellow liquid
  8. customThis was purified by flash column chromatograpgy on silica gel column

Sources & evidence

ORD record
ord-e549e393babf45018191c6c6e1a6d4be
Source dataset
uspto-grants-2014_12
Patent number
US08906929B2

Reaction notes

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