Ethyl diazoacetate → (+)-Ethyl 2-(4-bromo-2-fluorophenyl)cyclopropanecarboxylate

HRID 1392719Notes

Reaction equation

HRID 1392719 reaction equation
C(C1OC[C@@H](C(C)(C)C)N=1)(C1OC[C@@H](C(C)(C)C)N=1)(C)C.[Br:22][C:23]1[CH:28]=[CH:27][C:26]([CH:29]=[CH2:30])=[C:25]([F:31])[CH:24]=1.[N+](=[CH:34][C:35]([O:37][CH2:38][CH3:39])=[O:36])=[N-]>C(Cl)(Cl)Cl>[Br:22][C:23]1[CH:28]=[CH:27][C:26]([CH:29]2[CH2:30][CH:34]2[C:35]([O:37][CH2:38][CH3:39])=[O:36])=[C:25]([F:31])[CH:24]=1

Participants

5

Reactant 3

HCID 12192Ethyl diazoacetateHCID 688210t-Bu-box, (R,R)-HCID 166607744-Bromo-1-ethenyl-2-fluorobenzene

Product 1

HCID 58870011(+)-Ethyl 2-(4-bromo-2-fluorophenyl)cyclopropanecarboxylate

Reagents, catalysts & solvents 1

HCID 6212ChloroformSolvent3×

Procedure

To a suspension of copper(I) trifluoromethanesulfonate benzene complex (0.01 eq) in chloroform (100 mL) at rt, was added (R,R)-2,2′-isopropylidene-bis(4-tert-butyl-2-oxazoline) (0.01 eq). The mixture was stirred at for 1 h then cannulated through glass wool in a solution of styrene from step 5 (1.2 eq) in chloroform (0.1M) at 4° C. To this solution was added a solution of ethyl diazoacetate (0.8 eq) in of chloroform (1M) dropwise over 3 h. The final mixture was stirred overnight at 4° C. The mixture was concentrated. Flash chromatography (Hexane, EtOAc; 95:5) afforded the desired compound. (84:16, trans:cis isomers, methodology described in Evans et al. J. Am. Chem. Soc. 1991, 113, 726)

Workup

  1. concentrationThe mixture was concentrated

Sources & evidence

ORD record
ord-636d2852b8904b36aca3a8ad5e3b7a9a
Source dataset
uspto-grants-2008_03
Patent number
US07342024B2

Reaction notes

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