Equipment and Some General Remarks Concerning Performance of the Procedures

Laboratory Equipment and some General Remarks Concerning Performance of the Procedures 

The reaction vessel (Fig. 1) for most procedures in this volume is a round-bottomed flask with three vertical necks, fitted with a mechanical stirrer on the middle neck (a glass rod of no less than 5 mm diameter with a blade, and connected to a stirring motor)3. On the other necks are placed a dropping funnel, combined with a gas-inlet, connected to a supply for inert gas, and a thermometer combined with a gas-outlet. Deviations from or variants on this equipment are indicated in the descriptions of the respective procedures. Prior to charging the reaction flask and dropping funnel with solvents and/or reagents, the air in the apparatus is purged 

Instead of continuously introducing inert gas one may connect a balloon filled with gas (1 to 1.5 litre) to the flask. Of course, all connections should then be gas-tight so that during cooling no air can leak into the flask. 

Solutions of basic organometallic reagents such as H-butyllithium can be stored in an Erlenmeyer flask provided with a device for the introduction of inert gas while 

Many Grignard solutions in Et20 or THF may be stored at room temperature in the same sort of flask. Most solutions remain homogeneous at reagent concentrations of about 1 mol/1, otherwise some warming (30-40 °C) may be applied to effect dissolution of the salts. 

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