Reaction #68084

Reaction equation

sodium triacetoxyborohydride

dichloromethane

ethyl 1-(2-(2,3-dihydro-1,4-benzodioxin-6-yl)ethyl)piperazine-2-carboxylate

(7-methoxy-4-methyl-2-oxoquinolin-1(2H)-yl)acetaldehyde

→

ethyl 1-(2-(2,3-dihydro-1,4-benzodioxin-6-yl)ethyl)-4-(2-(7-methoxy-4-methyl-2-oxoquinolin-1(2H)-yl)ethyl)piperazine-2-carboxylate

Yield 64.8%

Solvents

acetic acid

water

chloroform

Conditions

Workup

1. 1
   workup.ADDITIONwere added
2. 2
   workup.STIRRINGstirred at room temperature for 1 hour
3. 3
   Otherthe organic layer was separated
4. 4
   Extractionthe aqueous layer was extracted with chloroform
5. 5
   Dryingdried over anhydrous magnesium sulfate
6. 6
   Otherthe solvent was removed under reduced pressure
7. 7
   OtherThe residue thus obtained
8. 8
   Otherwas purified by silica gel column chromatography [eluent; chloroform: acetone=50:1]

Procedure

To 2.5 mL of dichloromethane solution containing 0.14 g of ethyl 1-(2-(2,3-dihydro-1,4-benzodioxin-6-yl)ethyl)piperazine-2-carboxylate and 0.10 g of (7-methoxy-4-methyl-2-oxoquinolin-1(2H)-yl)acetaldehyde, 25 μL of acetic acid were added and stirred at room temperature for 50 min. Then, 0.14 g of sodium triacetoxyborohydride was added, and stirred at room temperature for 1 hour. To the reaction mixture, chloroform and water were added, the organic layer was separated, and the aqueous layer was extracted with chloroform. The organic layer and extracts were combined, dried over anhydrous magnesium sulfate, and the solvent was removed under reduced pressure. The residue thus obtained was purified by silica gel column chromatography [eluent; chloroform: acetone=50:1], to give 0.15 g of ethyl 1-(2-(2,3-dihydro-1,4-benzodioxin-6-yl)ethyl)-4-(2-(7-methoxy-4-methyl-2-oxoquinolin-1(2H)-yl)ethyl)piperazine-2-carboxylate as a colorless foam.

Source