Reaction #3867

Reaction equation

1,3-dibromopropane

product

8-Hydroxy-4-piperidino-2,3-dihydrobenzopyran

potassium hydroxide

H2O

→

desired product

8-(3-Bromopropoxy)-4-piperidino-2,3-dihydrobenzopyran

Solvents

diethyl ether

Conditions

Workup

1. 1
   Extractionextracted with 5% aq. HCl
2. 2
   WashThe acidic solution is washed with ether
3. 3
   Otherdried
4. 4
   Filtrationfiltered
5. 5
   Otherevaporated in vacuo

Procedure

Crushed potassium hydroxide (4.1 g) and tetrabutyl ammonium chloride (2.2 g) and H2O (5 ml) are added to a stirred mixture of the product obtained in Step 3. (17.2 g) and 1,3-dibromopropane (74.8 ml). The reaction mixture is stirred under nitrogen overnight, diluted with diethyl ether, and extracted with 5% aq. HCl. The acidic solution is washed with ether, sat'd NaCl, dried, filtered and evaporated in vacuo yielding the desired product as an oil.

Source