Perchloric Acid → HCID 117626364, compound

HRID 921070Notes

Reaction equation

HRID 921070 reaction equation
[Cl:1][C:2]1[N:7]2[N:8]=[C:9]([C:11]([O:13][CH2:14][CH3:15])=[O:12])[CH:10]=[C:6]2[N:5]=[C:4]([CH3:16])[C:3]=1[C@H:17]([OH:23])[C:18]([O:20][CH2:21][CH3:22])=[O:19].Cl(O)(=O)(=O)=O>C(Cl)Cl.C(OC(C)(C)C)(=O)C>[C:3]([O:23][C@@H:17]([C:3]1[C:4]([CH3:16])=[N:5][C:6]2[N:7]([N:8]=[C:9]([C:11]([O:13][CH2:14][CH3:15])=[O:12])[CH:10]=2)[C:2]=1[Cl:1])[C:18]([O:20][CH2:21][CH3:22])=[O:19])([CH3:17])([CH3:4])[CH3:2]

Participants

5

Reactant 2

HCID 24247Perchloric AcidHCID 117626446HCID 117626446, compound

Product 1

HCID 117626364HCID 117626364, compoundYield 172%

Reagents, catalysts & solvents 2

HCID 6344DichloromethaneSolvent2×HCID 10908tert-Butyl acetateSolvent

Procedure

To a stirred solution of (S)-ethyl 7-chloro-6-(2-ethoxy-1-hydroxy-2-oxoethyl)-5-methylpyrazolo[1,5-a]pyrimidine-2-carboxylate (200 mg, 0.585 mmol) in CH2Cl2 (6 mL) and t-butyl acetate (4 mL) at rt was added perchloric acid (0.151 mL, 1.756 mmol). The reaction flask was sealed. After stirring for 3 h, the reaction mixture was diluted with CH2Cl2 (50 mL), carefully quenched with sat. aq. NaHCO3 (5 mL). The organic layer was separated and washed with brine (5 mL), dried (Na2SO4), filtered and concentrated in vacuo to give a yellow liquid. This crude product was purified by flash column chromatography on a silica gel column using (10-50% EtOAc/Hex as eluant) to afford the desired (S)-ethyl 6-(1-(tert-butoxy)-2-ethoxy-2-oxoethyl)-7-chloro-5-methylpyrazolo[1,5-a]pyrimidine-2-carboxylate (200 mg, 0.503 mmol, 86% yield) as viscous oil. 1H NMR (400 MHz, CDCl3) δ 7.19 (s, 1H), 5.66 (s, 1H), 4.52 (q, J=7.2 Hz, 2H), 4.25-4.19 (m, 2H), 2.72 (s, 3H), 1.51-1.45 (m, 3H), 1.28 (s, 9H), 1.26-1.21 (m, 3H). LCMS (M+1)=398.25.

Workup

  1. customThe reaction flask was sealed
  2. customcarefully quenched with sat. aq. NaHCO3 (5 mL)
  3. customThe organic layer was separated
  4. washwashed with brine (5 mL)
  5. dry with materialdried (Na2SO4)
  6. filtrationfiltered
  7. concentrationconcentrated in vacuo
  8. customto give a yellow liquid
  9. customThis crude product was purified by flash column chromatography on a silica gel column

Sources & evidence

ORD record
ord-ec4d36841ed0446fb52403cad45a9811
Source dataset
uspto-grants-2016_03
Patent number
US09273067B2

Reaction notes

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