Diisopropylamine → Lithium diisopropylamide

HRID 2215201Notes

Reaction equation

HRID 2215201 reaction equation
[CH:1]([NH:4][CH:5]([CH3:7])[CH3:6])([CH3:3])[CH3:2].[Li:8]CCCC.[CH2:13]([O:15][CH2:16][C:17]([O:19][CH2:20][CH3:21])=[O:18])[CH3:14].[C:22]([C:26]1[O:27][C:28]([CH3:44])=[C:29]([CH2:31][O:32][C:33]2[C:41]3[CH:40]=[CH:39][S:38][C:37]=3[C:36]([CH:42]=[O:43])=[CH:35][CH:34]=2)[N:30]=1)([CH3:25])([CH3:24])[CH3:23]>C1COCC1>[Li+:8].[CH3:2][CH:1]([N-:4][CH:5]([CH3:7])[CH3:6])[CH3:3].[CH2:20]([O:19][C:17](=[O:18])[CH:16]([O:15][CH2:13][CH3:14])[CH:42]([C:36]1[C:37]2[S:38][CH:39]=[CH:40][C:41]=2[C:33]([O:32][CH2:31][C:29]2[N:30]=[C:26]([C:22]([CH3:25])([CH3:24])[CH3:23])[O:27][C:28]=2[CH3:44])=[CH:34][CH:35]=1)[OH:43])[CH3:21]

Participants

7

Reactant 4

HCID 7912DiisopropylamineHCID 69955Ethyl ethoxyacetateHCID 219496234-(2-tert-Butyl-5-methyl-oxazol-4-ylmethoxy)-benzo[b]thiophene-7-carbaldehydeHCID 178418339Butyllithium

Product 2

HCID 2724682Lithium diisopropylamideHCID 694870563-[4-(2-tert-Butyl-5-methyl-oxazol-4-ylmethoxy)-benzo[b]thiophen-7-yl]-2-ethoxy-3-hydroxy-propionic acid ethyl ester

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent4×

Procedure

LDA-solution in THF was prepared according to standard procedure from 0.180 g of diisopropylamine (1.783 mmol) and 1.080 ml of 1.5 M nBuLi (hexane) in 3 ml of abs. THF at −10°. After cooling to −75°, 0.214 g of ethyl ethoxyacetate (1.62 mmol), dissolved in 1.0 ml of THF, was added and stirring continued for 30 Min. to complete enolate formation. 0.178 g of the above prepared 4-(2-tert-butyl-5-methyl-oxazol-4-ylmethoxy)-benzo[b]thiophene-7-carbaldehyde (0.540 mmol), dissolved in 2.0 ml of THF, was then added at −75° and the mixture kept for another 30 Min. at this temperature. Pouring onto crashed ice/NH4Cl, twofold extraction with AcOEt, washing with water, drying over magnesium sulfate, and evaporation of the solvents, followed by flash chromatography (SiO2, hexane/AcOEt=7/3) afforded 0.201 g of the title compound (syn/anti-isomers) as yellowish oil.

Workup

  1. customat −10°
  2. temperatureAfter cooling to −75°
  3. additionwas added
  4. additionwas then added at −75°
  5. additionPouring
  6. extractionice/NH4Cl, twofold extraction with AcOEt
  7. washwashing with water
  8. dry with materialdrying over magnesium sulfate, and evaporation of the solvents

Sources & evidence

ORD record
ord-ce9a42ea4c2a440086f467e79cd0e7f8
Source dataset
uspto-grants-2006_09
Patent number
US07109225B2

Reaction notes

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