Ethyl bromoacetate → HCID 19848832, compound

HRID 1905138Notes

Reaction equation

HRID 1905138 reaction equation
C([Li])CCC.C(NC(C)C)(C)C.[CH2:13]([O:20][C:21]1[C:26]2[CH:27]([C:33]([O:35][CH3:36])=[O:34])[CH2:28][C:29]([CH3:32])([CH3:31])[O:30][C:25]=2[CH:24]=[C:23]([C:37]([CH3:45])([CH3:44])[CH2:38][CH2:39][CH2:40][CH2:41][CH2:42][CH3:43])[CH:22]=1)[C:14]1[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=1.Br[CH2:47][C:48]([O:50][CH2:51][CH3:52])=[O:49]>CCCCCC.CCCCCC.C(OCC)C.C1COCC1>[CH2:13]([O:20][C:21]1[C:26]2[C:27]([CH2:47][C:48]([O:50][CH2:51][CH3:52])=[O:49])([C:33]([O:35][CH3:36])=[O:34])[CH2:28][C:29]([CH3:32])([CH3:31])[O:30][C:25]=2[CH:24]=[C:23]([C:37]([CH3:44])([CH3:45])[CH2:38][CH2:39][CH2:40][CH2:41][CH2:42][CH3:43])[CH:22]=1)[C:14]1[CH:15]=[CH:16][CH:17]=[CH:18][CH:19]=1

Participants

8

Reactant 4

HCID 7748Ethyl bromoacetateHCID 7912DiisopropylamineHCID 19848809HCID 19848809, compoundHCID 178418339Butyllithium

Product 1

HCID 19848832HCID 19848832, compound

Reagents, catalysts & solvents 3

HCID 8028TetrahydrofuranSolvent2×HCID 8058HexaneSolventHCID 21584099Diethylether hexaneSolvent

Conditions

Temperature
-78 °C

Procedure

Under anhydrous conditions, under a nitrogen atmosphere 5.31 ml. of 1.6 molar n-butyllithium in hexane is charged to a flask containing 80 ml. dry tetrahydrofuran at -78° C. A solution of 1.2 ml. (848 mg., 8.4 mmole) freshly distilled diisopropylamine is added dropwise and the resulting mixture stirred at -78° C. for three hours. Then a solution of 3.1 g. (6.85 mmole) methyl 5-benzyloxy-2,2-dimethyl-7-(1,1-dimethylheptyl)-3,4-dihydro-2H-benzopyran-4-carboxylate (Example 88, Part B) in 10 ml. THF is added slowly and the resulting mixture stirred for three hours at -78° C. To this is added dropwise 1.40 g. (8.4 mmole) ethyl bromoacetate and the mixture stirred for 15 minutes. The reaction is quenched by addition of acetic acid and the mixture allowed to warm to ambient temperature. The product was isolated by the procedure described in Example 3, Part A, to obtain 2.89 g. (78%) of the desired diester, Rf 0.29, hexane/ethyl ether, 3:1.

Workup

  1. additioncontaining 80 ml
  2. customat -78° C
  3. stirringthe resulting mixture stirred for three hours at -78° C
  4. additionTo this is added dropwise 1.40 g
  5. customThe reaction is quenched by addition of acetic acid
  6. temperatureto warm to ambient temperature
  7. customThe product was isolated by the procedure
  8. customto obtain 2.89 g

Sources & evidence

ORD record
ord-131c4bde1db643e9b1aa4f3eb3369fc4
Source dataset
uspto-grants-1989_06
Patent number
US04841078

Reaction notes

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