Water-jacketed condenser

Flask F is provided with a two-hole cork stopper connected with tube E, and with tube G which connects with the first condenser II and may be of smaller bore than tubes C and E. H is. a. condenser with a 30-cm. water jacket. H is connected with I by means of an adapter. / is a i-l. round-bottom flask supported in a pan which is at first filled with ice and later used as a water bath. Flask I is fitted with a two-hole cork stopper carrying the adapter connected with condenser H and a Vigreux column K of 2-cm. diameter and a length of 30 cm. to the side arm. Flask I and condenser H are covered with black cloth (Note 2). The side arm of K is connected with a 90-cm. water-jacketed condenser L which leads into M through an adapter, iff is a 750-cc. Erlen-meyer flask immersed in an ice bath. Flask M is provided with a two-hole stopper connected with the adapter from L and an upright bulb condenser that is provided with a tube leading through a window or to a hood. 

This preparation is divided into three steps (1) the reaction of phosphorus (V) chloride with ammonium chloride in an inert solvent, (2) the rapid distillation from the solvent and from the nondistillable, rubber-forming higher polymers, and (3) the fractionation of the trimeric and tetra-meric compounds. The reaction apparatus consists of a 5-1. three-necked flask with standard-taper joints fitted with a thermometer and a motor-driven, heavy-duty stirrer, and heated by an electric mantle. For the preliminary removal of water from the solvent a Dean and Stark trap is used at a side joint in conjunction with a long water-jacketed condenser, the latter having a calcium chloride drying tube at its upper end. 

Monomeric 1,3-cyclopentadiene is obtained by the thermal cracking of cyclopentadiene dimer which is heated at about 150° in a nitrogen atmosphere in a distillation apparatus with a water-jacketed condenser. The fraction which boils below 44° is collected at 0° and is then degassed and stored in vacuo at — 78°. ... 

When the solution is dry, the solvent can be removed by distillation. If ether or any other very volatile and inflammable liquid is used, the flask containing the solvent should be heated on a water-bath, and should be provided with a long water-jacketed condenser and a special form of receiver. This is made by attaching to the condenser, by means of a tightly fitting... 

Unfortunately, you can t drop an O-ring and cap over a water-jacketed condenser, Hickman still, and so on. What to do Using the water-jacketed condenser as an example, go from the bottom up ... 

To a three-neck, 250-mL round-bottomed flask equipped with a water-jacketed condenser and nitrogen inlet and outlet lines were charged 75 g of ethanol, hexane, or 2-ethylhexanol solution. Magnetic stirrers were used to maintain constant agitation. In cases where reductions were accomplished at an elevated temperature (45°C), flasks were immersed in constant-temperature oil baths. Solutions were allowed to equilibrate with the surroundings before appropriate reducing agents were introduced. 

In a 100-mL three-necked round-bottomed flask equipped with a magnetic stirring bar, a nitrogen inlet, and a water-jacketed condenser, 0.34 g (1.3 mmole) of hydrated ruthenium trichloride is completely dissolved, under nitrogen, in absolute ethanol (8 mL). 1,3-Cycloheptadiene (5.0 mL, 46 mmole) and zinc dust (3.0 g, 46 mmole) are added in that order, and the mixture is heated at 80° for 1 hr. 

To a 10-mL round-bottom flask, add 0.24 g of finely ground frans-chalcone, 0.15 g of ethyl acetoacetate, and 5 mL of absolute ethanol. Swirl the flask until all or most of the solid dissolves and place a boiling stone in the flask. Add 0.25 mL of 2.2M NaOH to the mixture. Attach a water-jacketed condenser to the round-bottom flask and heat the mixture to reflux using an aluminum block and hot plate. Once the mixture has been brought to a gentle boil, continue to reflux the mixture for at least... 

Working in a hood, place 0.50 g of the acid and 2 mL of thionyl chloride into a small round-bottom flask. Add a magnetic stir bar, and attach a water-jacketed condenser and a drying tube packed with calcium chloride to the flask. While stirring, heat the reaction mixture to boiling for 30 minutes on a hot plate. Allow the mixture to cool to room temperature. Use this mixture to prepare the amide, anilide, or p-toluidide derivatives by one of the following three procedures. 

The components of the apparatus for heating a reaction under reflux on the microscale are the same as for a preparative scale reaction. A common set-up is shown in Figure 2.67. It is generally best to use a water-jacketed condenser to prevent any vapors from escaping a short-air condenser is frequently inadequate for the more volatile organic solvents such as diethyl ether and dichloromethane. 

Two types of condensers (air condensers and water-jacketed condensers) are available in most cases the water-jacketed condenser can work well as an air condenser. Condensers are usually attached to 14/10 I-jointed reaction flasks. The upper female joints allow connection of the condenser to the 14/10 1 drying tube and the 14/10 I capillary gas delivery tube (see Fig. 3.2). 

Air condensers can occasionally be used with lower boiling systems however, the water-jacketed condenser is more often employed in these situations. 

The water-jacketed condenser employs flowing cold water to remove heat from the vertical column and thus facilitate vapor condensation. It is highly effective at condensing vapor from low-boiling liquids. 

Figure 3.13 Water-jacketed condenser with conical vial, arranged for heating and magnetic stirring.

An alternative popular procedure for the generation of small quantities (1-50 mmol) of diazomethane from Diazald employs a commercial mini-Diazald apparatus with a dry-ice/acetone cold finger in place of the water-jacketed condenser. The generation of diazomethane is carried out by treatment of the Diazald with KOH in aqueous ethanol. ... 

---