Solvent agitating bath

A solution of 3 methoxy-10-(3 chloro-2-methylpropyl)phenthia2ine (9.65 grams) and 4-hydroxypiperidine (6.1 grams) in xylene (lOcc) is heated under reflux for 5 hours. After cooling the mixture is diluted with ether (60 cc) and the basic compounds are extracted by agitation with water (30 cc) and 4N hydrochloric acid (20 cc). The aqueous acid phase is made alkaline with 4N sodium hydroxide solution (23 cc) and the liberated base is extracted with ether. The ethereal solution is washed with water (60 cc) and dried over sodium sulfate. Finally the solvent is distilled off on a water-bath. 

Soil extraction using all types of aqueous solutions and ultrasonic agitation has been carried out. Simple apparatus such as extractant and aqueous solvent in an Erlenmeyer flask or test tube are used. An ultrasonic bath with Erlen-meyer flask is shown in Figure 11.7 (the use of an ultrasonic horn is shown in Figure 12.9). Ultrasonic extraction is typically carried out when the soil particles are not well separated, such as high clay soils, and thus the surfaces are not exposed to the extracting solutions. 

At the end of the experiment, the stirrer and heaters were switched off and the autoclave allowed to cool to room temperature. The autoclave was opened and the liquid contents were removed by suction. The basket was detached and the catalyst removed into a beaker which was placed in an ultrasonic bath. 10 cm of dichloroethane was added to the beaker which was agitated in the ultrasonic bath for 15 mins. The solvent was removed by suction filtration, the catalyst was washed with portions of acetone until the washings were colourless and the catalyst was air dried. The liquid product was transferred into a glass jar which was sealed under nitrogen and kept in a refrigerator until required. In order to have a sufficient amount of catalyst for a duplicate experiment on the five contacts and to allow a sample of catalyst to be... 

Liquefaction to produce filtered extract solution was carried out in a 2-1 autoclave under the conditions described previously and elsewhere (9). Solvent precipitation experiments using the filtered extract solution were carried out in a 0.2-1 autoclave. The extract and solvent were mixed together cold, in the autoclave, and heated to the extraction temperature in a fluidised sand bath. The mixture was agitated at the required temperature for 20 minutes and then filtered through a pressure filter containing a nomex cloth, at the extraction temperature, using the pressure in the autoclave or an iq lied nitrogen pressure. In some eiq)eriments, the solvent was injected, under pressure, into extract solution already at the required temperature. 

Pipet about 5-10 MBq (about 250 000-500 000 dpm) ofSoln. Ainto a 4-ml test tube. Carefully vaporize the solvent by a gentle stream of dry nitrogen. Add 10 pi of protein solution, containing 2-5 pg of protein in Soln. B, and agitate the tube in an ice bath for 30 min. Add 0.5 ml Soln. C and continue shaking at 0 °C. Fill up to 1 ml with Soln. D after an additional 5 min. Separate the labeled protein from the unreacted reagent as described in Protocol 6.4.1. 

The isomerized rosin, 245 g. (0.72 mole) (Note 1), is placed in a 1-1. Erlenmeyer flask and dissolved in 375 ml. of acetone by heating the mixture on a steam bath. To this solution, at incipient boiling, is added slowly and with vigorous agitation (Note 5) 127 g. (0.81 mole) of diamylamine 2 (Note 6). Upon cooling to room temperature, crystals appear in the form of rosettes. The mass is agitated, cooled well in an ice bath, and filtered by suction. The crystalline salt is washed on a Buchner funnel with 150 ml. of acetone and dried in a vacuum oven at 50° for 1 hour. The optical rotation of this material is [< ]d —18° (Note 4). The solid is recrystallized four times from acetone. Each time a sufficient quantity (20 ml. per g.) of acetone is used to obtain complete solution, and the solvent is evaporated until incipient precipitation of the salt occurs. The yield of product is 118 g. [ ]d —60° (Note 4). An additional 29 g. of product, having the same rotation, can be recovered from filtrates of the previous crystallizations. 

The suspension is transferred to a 5-1. three-necked round-bottomed flask and subjected to steam distillation until 7-10 1. are collected (Note 10). The toluene layer is removed, and the aqueous layer is extracted with 1 1. of fresh toluene. The combined toluene layers are agitated for 30 minutes with a solution of 26 g. of sodium bisulfite in 500 ml. of water (Note 11). The toluene layer is washed with water, and the solvent is removed at water-pump pressure on the steam bath. The resulting orange liquid weighs 107-120 g. (65-74%) 1.5250-1.5270, and is... 

A solution of 1 eq. of the tert-butyl ester of 7-aminocephalosporanic acid and 1 eq. of dicyclohexylcarbodiimide in 100 ml of methylene chloride/DMF (1 1) is cooled to 0°C. The mixture is combined with 1 eq. of 3,5-dichloro-4-pyridone-l-acetic acid after 5 min the ice bath is removed and the mixture agitated for another 30 min at 25°C. The thus-formed urea is filtered off and the filtrate filtered over silica gel (eluent ethyl acetate/1% methanol). The solvent is concentrated by evaporation, and the thus-obtained tert-butyl ester of 7-(3,5-dichloro-l,4-dihydro-4-oxo-l-pyridylacetamido)cephalosporanic acid is crystallized from ether. 

A simple and effective form of degassing is to hold a flask of mobile phase under a vacuum while agitating the contents in an ultrasonic bath (Fig. 3.7). The eluent is then transferred to the chromatograph for several hours of reliable operation, especially if the eluent is blanketed with an inert gas such as helium. This approach is particularly useful for clean solvents that readily absorb gases such as carbon dioxide from the atmosphere. The eluent should be degassed in the solvent storage container used for chromatography to minimize contact with the air. 

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