Ammonium Chloride → HCID 68833946, compound

HRID 1454102Notes

Reaction equation

HRID 1454102 reaction equation
C[Si]([N-][Si](C)(C)C)(C)C.[Li+].[Si:11]([O:18][C:19]1[CH:24]=[CH:23][C:22]([CH2:25][C:26]([O:28][CH2:29][C:30]2[CH:35]=[CH:34][CH:33]=[CH:32][CH:31]=2)=[O:27])=[CH:21][CH:20]=1)([C:14]([CH3:17])([CH3:16])[CH3:15])([CH3:13])[CH3:12].[C:36]([O:40][C:41](=[O:44])[CH2:42]Br)([CH3:39])([CH3:38])[CH3:37].[Cl-].[NH4+]>C1COCC1>[Si:11]([O:18][C:19]1[CH:24]=[CH:23][C:22]([CH:25]([CH2:42][C:41]([O:40][C:36]([CH3:39])([CH3:38])[CH3:37])=[O:44])[C:26]([O:28][CH2:29][C:30]2[CH:35]=[CH:34][CH:33]=[CH:32][CH:31]=2)=[O:27])=[CH:21][CH:20]=1)([C:14]([CH3:16])([CH3:17])[CH3:15])([CH3:13])[CH3:12]

Participants

6

Reactant 4

HCID 25517Ammonium ChlorideHCID 79177tert-Butyl bromoacetateHCID 2733832Lithium HexamethyldisilazideHCID 86608538HCID 86608538, compound

Product 1

HCID 68833946HCID 68833946, compoundYield 94%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

Lithium bis(trimethylsilyl)amide (1.06 M in THF; 12.6 mL, 13.3 mmol) was added dropwise over 10 min to a stirred solution of benzyl (4-{[tert-butyl(dimethyl)silyl]oxy}phenyl)acetate (4.32 g, 12.1 mmol) in THF (40 mL) at −78° C. under nitrogen. On completion of addition stirring was continued at −78° C. for 30 min then t-butylbromoacteate (2.82 g, 2.14 mL, 14.5 mmol) was added dropwise over 5 min. The reaction was allowed to warm slowly to room temperature over 4 h then saturated ammonium chloride solution (40 mL) was added and the resulting suspension extracted with ethyl acetate (3×50 mL). The organic phases were combined, dried (magnesium sulfate) and evaporated to dryness. The residue was chromatographed on silica gel (5% diethyl ether: cyclohexane) to give the title compound as a colourless oil (5.35 g, 94%). LC/MS: 4.35 min; z/e 488, calcd (M+18) 488. 1H NMR (400 MHz: CDCl3): 7.10 (3H), 7.05 (2H), 6.95 (2H), 6.60 (2H), 4.95 (2H), 3.85 (1H), 2.90 (1H), 2.40 (1H) 1.20 (9H), 0.8 (9H), 0.05 (6H).

Workup

  1. additionOn completion of addition
  2. extractionthe resulting suspension extracted with ethyl acetate (3×50 mL)
  3. dry with materialdried (magnesium sulfate)
  4. customevaporated to dryness
  5. customThe residue was chromatographed on silica gel (5% diethyl ether: cyclohexane)

Sources & evidence

ORD record
ord-172b6c4bb3ba4cbd9d8975e12b973a7a
Source dataset
uspto-grants-2009_01
Patent number
US07476759B2

Reaction notes

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