Sodium hydride → (R)-2-Ethyl-piperazine-1,4-dicarboxylic acid 4-tert-butyl ester 1-(4-cyclopropylmethoxy-2,6-difluoro-benzyl)ester

HRID 1794142Notes

Reaction equation

HRID 1794142 reaction equation
[CH:1]1([CH2:4][O:5][C:6]2[CH:13]=[C:12]([F:14])[C:9]([CH2:10][OH:11])=[C:8]([F:15])[CH:7]=2)[CH2:3][CH2:2]1.[C:16]([O:20][C:21]([N:23]1[CH2:28][CH2:27][N:26]([C:29](Cl)=[O:30])[C@H:25]([CH2:32][CH3:33])[CH2:24]1)=[O:22])([CH3:19])([CH3:18])[CH3:17].[H-].[Na+]>CN(C)C=O>[CH:1]1([CH2:4][O:5][C:6]2[CH:7]=[C:8]([F:15])[C:9]([CH2:10][O:11][C:29]([N:26]3[CH2:27][CH2:28][N:23]([C:21]([O:20][C:16]([CH3:18])([CH3:17])[CH3:19])=[O:22])[CH2:24][C@H:25]3[CH2:32][CH3:33])=[O:30])=[C:12]([F:14])[CH:13]=2)[CH2:3][CH2:2]1

Participants

5

Reactant 3

HCID 24758Sodium hydrideHCID 222200444-Cyclopropylmethoxy-2,6-difluoro-benzylalcoholHCID 86586001(R)-4-Chlorocarbonyl-3-ethyl-piperazine-1-carboxylic acid tert-butyl ester

Product 1

HCID 69194614(R)-2-Ethyl-piperazine-1,4-dicarboxylic acid 4-tert-butyl ester 1-(4-cyclopropylmethoxy-2,6-difluoro-benzyl)esterYield 71%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent2×

Procedure

A mixture of 4-cyclopropylmethoxy-2,6-difluoro-benzylalcohol (270 mg, 1.26 mM) and (R)-4-chlorocarbonyl-3-ethyl-piperazine-1-carboxylic acid tert-butyl ester (349 mg, 1.26 mM) in dimethylformamide (2 mL) was added slowly to a suspension of sodium hydride (83 mg, 55%, 1.89 mM) in dimethylformamide (2 mL). The mixture was stirred at room temperature for 5 h and partitioned between water and diethylether. Organic phases were pooled, washed with brine and dried with MgSO4 to yield after evaporation a yellow oil (585 mg). This residue was purified by column chromatography (silica gel; n-hexane/ethylacetate gradient) to yield 406 mg (71%) of the product as a yellowish oil. MS (ISP): 477.3 (M+H)+.

Workup

  1. custompartitioned between water and diethylether
  2. washwashed with brine
  3. dry with materialdried with MgSO4
  4. customto yield
  5. customafter evaporation a yellow oil (585 mg)
  6. customThis residue was purified by column chromatography (silica gel; n-hexane/ethylacetate gradient)

Sources & evidence

ORD record
ord-16ba112d664c42b686df706ff097b6c4
Source dataset
uspto-grants-2006_04
Patent number
US07022707B2

Reaction notes

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