Ethyl Bromide → 1-[(2-Methoxypropan-2-yl)oxy]pent-2-yne

HRID 2167154

Reaction equation

HRID 2167154 reaction equation
C=C[C:3]1[CH:8]=[CH:7][CH:6]=[CH:5]C=1.[NH2-].[Li+].[CH3:11][O:12][C:13]([CH3:19])([O:15]CC#C)[CH3:14].BrCC>CCCCCC>[CH3:11][O:12][C:13]([CH3:19])([O:15][CH2:5][C:6]#[C:7][CH2:8][CH3:3])[CH3:14]

Participants

6

Reactant 4

HCID 6332Ethyl BromideHCID 7501StyreneHCID 24532Lithium amideHCID 30178913-(1-Methoxy-1-methylethoxy)propyne

Product 1

HCID 30198311-[(2-Methoxypropan-2-yl)oxy]pent-2-yneYield 96.9%

Reagents, catalysts & solvents 1

HCID 8058HexaneSolvent

Procedure

883 mg (126 mmol) of granulated lithium were added within 5 minutes to 107 g (6.30 mol) of liquid ammonia at −38° C. The mixture was stirred until no more lithium floated (after approximately 10 minutes). A dark blue solution of lithium in liquid ammonia was obtained. 14.6 g (140 mmol) of styrene were added portion wise within 20 minutes. The end of the formation of lithium amide could be recognized by the discoloration of the reaction mixture. 9.9 g (70 mmol) of 3-(1-methoxy-1-methyl-ethoxy)-propyne (90.8% GC) were added with a dropping funnel to the reaction mixture at −38° C. within 20 minutes. The reaction mixture was held at −38° C. for about 1 hour. 14 g (126 mmol) of bromoethane were added with a dropping funnel to the reaction mixture within 20 minutes. The reaction mixture was subsequently stirred for 1 hour. 100 ml of n-hexane were added to the reaction mixture and the liquid ammonia was evaporated under normal pressure within 16 hours. 70 ml of water were added to the reaction mixture at 22° C., and the mixture was stirred until all salt was dissolved. The organic layer was separated and dried over 2 g of anhydrous magnesium sulfate. The solution was concentrated under reduced pressure (40° C., 40 mbar) and the crude product was analyzed by GC. 10.6 g of 1-(1-methoxy-1-methyl-ethoxy)-pent-2-yne were obtained with a purity of 84.4% (yield 81.8%, based on 3-(1-methoxy-1-methyl-ethoxy)-propyne).

Workup

  1. customthe liquid ammonia was evaporated under normal pressure within 16 hours
  2. addition70 ml of water were added to the reaction mixture at 22° C.
  3. stirringthe mixture was stirred until all salt
  4. dissolutionwas dissolved
  5. customThe organic layer was separated
  6. dry with materialdried over 2 g of anhydrous magnesium sulfate
  7. concentrationThe solution was concentrated under reduced pressure (40° C., 40 mbar)

Sources & evidence

ORD record
ord-9f06442218214351bab49f9c17aa060f
Source dataset
uspto-grants-2015_06
Patent number
US09045404B2

Linked notes

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