Reaction #1755473

Reaction equation

propargyl bromide

tert-butyl-1-piperazine carboxylate

propargyl bromide

potassium carbonate

→

yellow oil

Yield 46.0%

4-Prop-2-ynyl-piperazine-1-carboxylic acid tert-butyl ester

Yield 46.0%

Solvents

dichloromethane

acetonitile

Conditions

Workup

1. 1
   OtherThe residue was evaporated to dryness
2. 2
   workup.ADDITIONDichloromethane, 50 mL, and water, 50 mL, were added
3. 3
   ExtractionThe reaction mixture was extracted with CH2Cl2, 4×40 mL
4. 4
   Dryingdried over magnesium sulfate
5. 5
   Otherevaporate
6. 6
   Otherto provide a brown oil
7. 7
   Otherpurify with a RT Scientific system

Procedure

To a solution of 10.0 g (54.8 mmol) of tert-butyl-1-piperazine carboxylate in 60 mL acetonitile was added 5.20 mL (60.4 mmol) propargyl bromide and 37.9 g (274 mmol) anhydrous potassium carbonate. Additional propargyl bromide, 1.5 mL, was added after stirring for 36 hours at room temperature. The residue was evaporated to dryness. Dichloromethane, 50 mL, and water, 50 mL, were added. The reaction mixture was extracted with CH2Cl2, 4×40 mL, dried over magnesium sulfate, and evaporate to provide a brown oil. The oil was dissolved in dichloromethane and purify with a RT Scientific system using hexane/ethyl acetate gradient to yield 5.5 g (46%) of yellow oil, which ultimately crystallized upon standing.

Source