Removal Of Ether Research Articles

Synthesis of N-t-Butyl Benzamides

Abstract N-t-butyl benzamides have been prepared by the reaction of t-butyl amine with the corresponding aroyl chloride in a solution of 10% aqueous sodium hydroxide1 and by the Ritter reaction using isobutylene and the appropriate aryl cyanide.2 We have found that N-t-butyl benzamides can be prepared in excellent yield by the reaction of one equivalent of aroyl acid chloride3 with an ethereal solution of one equivalent of t-butyl amine and one equivalent of triethyl amine. The role of the triethyl amine is that of a base to scavenge the one equivalent of hydrochloric acid produced in the reaction. Work-up of the reaction mixture consists simply of filtering the reaction mixture to remove the solid triethylammonium chloride and in vacuo removal of ether to afford the desired amide. Purification of the crude N-t-butyl benzamide may then be affected by either crystallization (ether-pentane mixtures) or by sublimation. The general reaction is given below in equation I, and representative yields are indicated...

The nature of volatile constituents of glues

AbstractThe volatile components of bone glues have been isolated by steam distillation. They were concentrated by ether extraction of either the neutralised aqueous distillate or of active charcoal, through which the aqueous distillate had been allowed to percolate, followed by drying and removal of the ether. Acidification of the neutralised aqueous distillate with phosphoric acid after the ether extraction, enabled the volatile acids of the glues to be concentrated by a further ether extraction, drying and removal of ether. The components of the concentrates were separated by gas chromatography and identified by mass spectrometry and/or infrared spectroscopy.Sixty‐eight compounds were positively identified and a further 19 tentatively. It has not proved possible to identify specific compounds responsible for specific off‐odours.

Spectrophotometric Determination of Bromvalerylurea with Dichlorofluorescein

A new method for the spectrophotometric determination of bromvalerylurea was established upon the reaction of 2', 7'-dichlorofluorescein and bromine. The method improved the usual method with fluorescein in the points of sensitivity of reaction and the linearity of calibration curve. Bromvalerylurea is extracted with ether from a sample containing 20-100μg of it. After the removal of ether, the extract is heated with 1 ml of ammonia water for 20 min on a water bath at 100° and evaporated. The dried residue was warmed for 20 min on a water bath at 40° after the addition with 2 drops of hydrogen peroxide and 1 ml of 2', 7'-dichlorofluorescein solution in glacial acetic acid (250 mg/liter). The reacted solution is added with 3 ml of pyridine and determined spectrophotometrically at 530 mμ. Bromdiethylacetylurea is determined similarly. The determination of bromvalerylurea in pharmaceutical preparations was carried out by this method and good results were obtained. Further study is required to apply this method for biological materials.

A method for detection and estimation of penicillin in poliomyelitis vaccine.

SummaryA method is described for determining penicillin in poliomyelitis vaccine. This method consists of acidifying the vaccine, extracting the penicillin into diethyl ether, removal of ether by vacuum distillation and transfer of penicillin into a buffer. The penicillin is determined by standard paper chromatographic and bioautographic technics. This method is capable of detecting 0.001 unit of penicillin/ml finished vaccine.