Diisopropylamine → t-Butyl 3-(3-bromomethylphenyl)propionate

HRID 444056Notes

Reaction equation

HRID 444056 reaction equation
C(NC(C)C)(C)C.C([Li])CCC.[C:13]([O:16][C:17]([CH3:20])([CH3:19])[CH3:18])(=[O:15])[CH3:14].[Br:21][CH2:22][C:23]1[CH:28]=[CH:27][CH:26]=[C:25]([CH2:29]Br)[CH:24]=1>O1CCCC1.CN(C)P(N(C)C)(N(C)C)=O>[Br:21][CH2:22][C:23]1[CH:24]=[C:25]([CH2:29][CH2:14][C:13]([O:16][C:17]([CH3:20])([CH3:19])[CH3:18])=[O:15])[CH:26]=[CH:27][CH:28]=1

Participants

7

Reactant 4

HCID 7912DiisopropylamineHCID 10908tert-Butyl acetateHCID 69373Benzene, 1,3-bis(bromomethyl)-HCID 178418339Butyllithium

Product 1

HCID 20436811t-Butyl 3-(3-bromomethylphenyl)propionate

Reagents, catalysts & solvents 2

HCID 8028TetrahydrofuranSolvent2×HCID 12679HexamethylphosphoramideSolvent

Procedure

A solution of di-isopropylamine (4.04 g) and butyl-lithium (25 ml, 1.60 M in hexane) in dry tetrahydrofuran (40.0 ml), stirred at -78° under dry nitrogen, was treated over 5 minutes with t-butyl acetate (4.64 g). To this solution was added, over 5 minutes, a solution of α,α'-dibromo-m-xylene (11.60 g) and dry hexamethylphosphoramide (1.42 g) in dry tetrahydrofuran (8.0 ml). The resulting yellow solution was stirred at -78° for 1/2 hour, then allowed to warm to room temperature over 3 hours. Excess ice-water was added, and the mixture extracted with ether, and the extract washed with 1 N hydrochloric acid (60 ml) then water. The dried extract was concentrated in vacuo, to give a yellow oil which was purified by column chromatography on silica, eluting with 1:1 ether:hexane, giving t-butyl 3-(3-bromomethylphenyl)propionate as a colourless oil. Using the method described in the last foregoing paragraph this was converted to the desired diethylester which was used in each of Examples 22 to 25.

Workup

  1. additionTo this solution was added, over 5 minutes
  2. extractionthe mixture extracted with ether
  3. washthe extract washed with 1 N hydrochloric acid (60 ml)
  4. extractionThe dried extract
  5. concentrationwas concentrated in vacuo
  6. customto give a yellow oil which
  7. customwas purified by column chromatography on silica
  8. washeluting with 1:1 ether

Sources & evidence

ORD record
ord-6ed5aea4d586419a82c1d08c38227744
Source dataset
uspto-grants-1981_04
Patent number
US04262128

Reaction notes

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