Removing Solvent by Rotary Evaporation

Turn on the rotary evaporator and set the water bath temperature to 140°C for organic solvents. Turn on the cooling water at a moderate flow rate through the condenser system.

Verify the receiver flask is empty, then pour the compound solution into the round-bottom flask. Carefully clip the flask into place on the rotary evaporator, being cautious with dense solvents like dichloromethane.

Open the tap to allow air to bleed through, then turn on the vacuum. Start rotating the flask to approximately the 1-2 o'clock position and gradually close the tap to establish vacuum.

Slowly lower the flask into the water bath so that the bottom portion is submerged. Increase the rotation speed to maximize surface area and prevent bumping during evaporation.

Allow the solvent to evaporate completely while monitoring the flask. Observe condensation forming on the glass and watch for the end of evaporation when the flask contents stop changing.

Reduce rotation speed to zero and raise the flask out of the water bath. Open the tap to bleed air into the system and turn off the vacuum.

Unclip and remove the flask from the rotary evaporator. Wipe the flask with a paper towel to dry it, and weigh it to determine the mass of recovered solid.

Turn off the rotary evaporator. Remove and empty the receiver flask of any collected solvent, then reassemble and store the equipment.