Conical reaction vials

One of the most versatile pieces of glassware contained in the microscale organic glassware kit is the conical reaction vial. This vial is used as a vessel in which organic reactions are performed. It may serve as a storage container. It is also used for extractions (see Technique 12). A reaction vial is shown in Figure 3. 

A conical reaction vial. (The inset shows an expanded view of the cap with its Teflon insert.)... 

A 10-mL round-bottom flask containing a spin bar and fitted with an air cooled condenser is used in place of the conical reaction vial ( ). 

Add 0.1 mL of borate buffer and 0.01 mL of reagent to 1 mL of unfiltered seawater sample in a pre-cleaned conical reaction vial (capacity ca. 2mL). Mix thoroughly and allow the mixture to react for exactly 10 min. Liebezeit and Dawson (1981) have shown that the ideal reaction pH for seawater is around 11.5. The reaction time of lOmin ensures more reproducible results and increases sensitivity. 

Get the material to be extracted into an appropriately sized conical vial. This vial should be at minimum twice the volume of the liquid you want to extract. Usually, this conical vial is the reaction vial for the experiment, so the choice is easily made (forced on you). 

Measure 0.15 mL of pure cinnamaldehyde (MW = 132.2, d = 1.11 g/mL) and place it in another small conical vial. Add 0.50 mL of absolute ethanol to the cinnamaldehyde Cap the vial until it is needed. After the 15-minute period, use a Pasteur pipette to mix the cinnamaldehyde with the ethanol and add this solution to the ylide in the reaction vial. A color change should be observed as the ylide reacts with the aldehyde and the product precipitates. Stir the mixture for 10 minutes. 

Remove the air condenser. In a hood, transfer 0.50 mL of chlorosulfonic acid CISOjOH (MW = 116.5, d = 1.77 g/mL) to the acetanilide in the conical vial using the graduated pipette provided. Reattach the air condenser and drying tube. Allow the mixture to stand for 5 minutes and then heat the reaction vial in the... 

In this case, preparative gas chromatography replaces conventional distillation as the route of choice to product purification. A number of the reaction products in Chapters 6, 7, and lOW depend on this approach for successful purifi- [Pg.27]

Purification and Characterization. Dry and purify the wet, crude ether solution of ethyl Iaurate by column chromatography. In a Pasteur filter pipet, place 500 mg of activated silica gel followed by 500 mg of anhydrous sodium sulfate (- ). Wet the column first with 0.5 mL of methylene chloride and then transfer the crude ether solution of ethyl Iaurate to the column using a Fhsteur filter pipet. Use a tared 5-mL conical vial containing a boiling stone as a collection flask for the column eluant. Rinse the reaction vial with methylene chloride (0.5 mL). Transfer the rinse to the column. Repeat both rinse and transfer with a second aliquot of methylene chloride (0.5 mL). Add an additional 1.0 mL of methylene chloride directly to the column to ensure complete elution of the ester. 

Reagents and Equipment. Using a 10-mL graduated cylinder, measure 2 mL of a 21 wt% solution of sodium ethoxide in ethanol ancl add it to a 5-mL conical vial containing a magnetic spin vane (use a precalibrated Fhsteur pipet for the transfer). Then equip the reaction vial with a Claisen head to which is connected a reflux condenser (- ). 

Usually, you warm the conical vial somehow to have the reaction generate the gas you want to collect. 

Amino acids were derlvatlzed with 1-dlmethylamlnonaphthalene-5-sulfonyl chloride (dansyl chloride) according to the procedure of Tapuhl and coworkers (48-50). A 10 M stock solution of twenty common -amlno acids (Sigma Chemical Co., St. Louis, MO) was prepared by dissolving the carefully weighed standards in 0.1 M aqueous hydrochloric acid. Aliquots of this solution were transferred to conical vials, evaporated to dryness, and redlssolved In 500 pL aqueous buffer (0.04 M lithium carbonate, pH 9.5). A 500 jL volume of dansyl chloride solution (5 x 10 3 m in acetonitrile) was added, and the derlvatlzatlon was allowed to proceed In the dark at 35"C for one hour. The reaction was terminated by the addition of 2% methylamlne hydrochloride, and the derlvatlzed sample was analyzed Immediately by mlcrocolumn liquid chromatography with UV-absorbance and LIF detection. 

Heat the reaction mixture with an aluminum block or sand bath at about 120°C (see inset in Technique 6, Figure 6.2A) and stir gently. If you are using a sand bath, the conical vial should be partially buried in the sand so that the vial is nearly at the bottom of the sand bath. After the solid has dissolved (it may dissolve, precipitate, and redissolve), heat the mixture for an additional 20 minutes to complete the reaction. 

The tertiary alkyl halide can be prepared by allowing f-pentyl alcohol to react with concentrated hydrochloric acid according to Equation 2. The reaction is accomplished simply by shaking the two reagents in a sealed conical vial. As the reaction proceeds, the insoluble alkyl halide product forms on upper phase. The reaction of the tertiary substrate occurs via an Sj. 1 mechanism. 

Cool the mixture for a few minutes and detach the air condenser. With a Pasteur pipette, transfer the reaction mixture to a beaker containing 4 mL of ice-cold water. Rinse the conical vial and spin vane with a small amount of water. Cool the mixture in an ice bath until the crystals have formed. If the material oils out rather than crystallizes, scratch the oil vigorously with a spatula until it does crystallize completely. Collect the crude product on a Hirsch funnel under vacuum. Wash it well with cold water (about 5 mL) to remove the nitric acid. Continue drawing air through the solid mass on the Hirsch funnel to help dry the solid. Weigh the solid. 

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