Hydrochloric Acid → HCID 178498633, compound

HRID 1993680Notes

Reaction equation

HRID 1993680 reaction equation
[CH3:1][Si:2]([CH:5]=[N+:6]=[N-:7])([CH3:4])[CH3:3].C([N-]C(C)C)(C)C.[Li+].[C:16]([O:20][CH3:21])(=[O:19])[C:17]#[CH:18].Cl>C1COCC1.O.C(OCC)(=O)C>[CH3:21][O:20][C:16]([C:17]1[NH:7][N:6]=[C:5]([Si:2]([CH3:4])([CH3:3])[CH3:1])[CH:18]=1)=[O:19]

Participants

8

Reactant 4

HCID 313Hydrochloric AcidHCID 13536Methyl propiolateHCID 167693TrimethylsilyldiazomethaneHCID 2724682Lithium diisopropylamide

Product 1

HCID 178498633HCID 178498633, compoundYield 36.2%

Reagents, catalysts & solvents 3

HCID 962WaterSolventHCID 8028TetrahydrofuranSolventHCID 8857Ethyl AcetateSolvent

Procedure

Place trimethylsilyl-diazomethane (2 M in THF) (25 mL, 50 mmol) in THF (50 mL). Cool the reaction to −78° C. and add lithium diisopropylamide (2 M in THF) (25 mL, 50 mmol) over 30 min. Add methyl propiolate (4.45 mL, 50 mmol) and stir at −78° C. for 2 hours. Warm to room temperature and stir for 18 hours. Add ethyl acetate, water, and 1 N HCl. Separate organic layer and extract aqueous with ethyl acetate (2×25 mL). Combine organic extracts, dry over Mg2SO4, filter, and concentrate under reduced pressure. Subject residue to silica gel chromatography eluting with 0-60% EtOAc:hexane to yield 3.59 g (36%) of 5-trimethylsilanyl-2H-pyrazole-3-carboxylic acid methyl ester.

Workup

  1. temperatureCool
  2. customthe reaction to −78° C.
  3. extractionSeparate organic layer and extract aqueous with ethyl acetate (2×25 mL)
  4. dry with materialCombine organic extracts, dry over Mg2SO4
  5. filtrationfilter
  6. concentrationconcentrate under reduced pressure
  7. washSubject residue to silica gel chromatography eluting with 0-60% EtOAc

Sources & evidence

ORD record
ord-98f0f11a3e914215b996b7afb7471e8b
Source dataset
uspto-grants-2010_01
Patent number
US07652015B2

Reaction notes

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