Preparation of Ammonium Hydroxide Ammonium hydroxide is prepared by saturating water with gaseous ammonia. Ammonia gas is generated and conducted directly from the flask without the introduction of a drying tube into an empty gas washing-bottle which serves to collect any solid particles mechanically carried over. Gaseous ammonia is prepared by gently heating crude ammonium chloride (or ammonium sulfate) with dry calcium hydroxide: Powdered ammonium chloride and calcium hydroxide in equal quantities are placed in Erlenmeyer flask fitted with a glass elbow. On the application of gentle heat ammonia is rapidly evolved. The gas is then conducted through a series of…
Author: Ethan Frank
Preparation of Benzoyl Chloride Benzoyl chloride could be prepared by reacting thionyl chloride or phosphorus pentachloride with benzoic acid. 50 grams of dry benzoic acid are treated in a 500 ml flask, with 90 grams of finely pulverized phosphorus pentachloride. The mixture is mixed well, upon which, after a short time, the reaction takes place with an energetic evolution of hydrochloric acid, and the reaction mass becomes liquid. During the reaction a lot of heat is released. After standing a short time, the completely liquid mixture is twice fractionated by collecting fraction which boils at ~ 200° C, yielding 90 %…
Preparation of Hydrogen Iodide The hydrogen iodide could be obtained by dehydrating hydroiodic acid with phosphorus pentoxide. The concentrated solution of hydroiodic acid added dropwise to the phosphorus pentoxide. The gas evolved was purified by passing trough a tube filled with phosphorus pentoxide and condensed with liquid nitrogen. Hydrogen iodide was distilled from the solid state and condensed in the receiver as white material.
Preparation of Iron iii Nitrate Iron iii Nitrate: To a mixture of 100 ml of concentrated nitric acid and 30 ml of water, 50 g of iron filings or fine turnings in small portions are added. The rate of reaction can be regulated by the rate of addition of iron and by gently heating the mixture but not above 70° C. When the iron has practically all dissolved, the solution is filtered and set it aside to crystallize. The filtrate is usually dark in color owing to the presence of colloidal basic nitrates. These salts are gradually converted into the…
Preparation of Cinnamic Acid Cinnamic Acid: A mixture of 20 grams of benzaldehyde, 30 grams of acetic anhydride, both freshly distilled, and 10 grams of anhydrous pulverized sodium acetate, is heated in a flask fitted with a reflux condenser, for 8 hours, at 180° C. After the reaction is complete, the hot reaction product is poured into a large flask. Water is added and then distilled with steam, until no more benzaldehyde passes over. The quantity of water used here is large enough so that all of the cinnamic asid dissolves except a small portion of an oily impurity. The…
Preparation of Pyrrolidine Pyrrolidine: 18 g of twice distilled from sodium pyrrole are dissolved in 60 ml of glacial acetic acid and hydrogenated with 0.5 g of platinum oxide. Absorption of hydrogen is throughout very slow and occasionally ceased completely, but the catalyst could be reactivated by shaking the reaction mixture with oxygen. Fresh portion platinum oxide (0.3 g) is added after 45 hours, and after 96-100 hours the theoretical amount of hydrogen has been absorbed. After the platinum has settled, the dark solution was decanted, the acetic acid was neutralized with concentrated solution of sodium hydroxide under a reflux condenser…
Preparation of Aluminium Bromide Aluminium Bromide: The ideal vessel for this experiment is a 250 ml tabulated retort with a wide neck (at least 15 mm in diameter). However, a distilling flask of similar size with a delivery tube 15 cm long and 15 mm in diameter sealed on its neck may be used as a substitute. Aluminium Bromide: Sixty grams of bromine, previously dried with concentrated sulfuric acid are placed in a small dropping funnel with a long delivery tube. The neck of the funnel is protected with a drying tube. Ten grams of aluminum (30-mesh or turnings) are placed…
Preparation of 1-bromobutane 1-bromobutane: A mixture of 30 ml of water, 35 g of powdered sodium bromide and 25 ml (or 20 g) of 1-butanol are placed in a 250 ml round-bottomed flask. The flask is fitted with a dropping funnel with pressure-equalization arm. 25 ml of concentrated sulfuric acid is placed in the funnel and added dropwise into the reaction mixture with constant stirring and occasional cooling in an ice-water bath. When the addition of sulfuric acid is complete, the dropping funnel is replaced with a reflux condenser, and the reaction mixture is gently boiled for 45 minutes, shaking the…
Preparation of Acetaldehyde Ethanal Ethanal: To a 1-liter round bottom flask fitted with a dropping funnel, a distillation head with a condenser and mechanical stirrer 60 ml of concentrated sulfuric acid dissolved in 200 ml of water are placed. The diluted sulfuric acid is heated to boiling and 200 g of sodium dichromate in 200 ml of water which has been treated with 100 g of ethyl alcohol is then added in a small portion through the dropping funnel. During the addition of the sodium dichromate heat evolves and causes ebullition of the reaction mixture. The Ethanal, which forms during the…
Synthesis of Jones Reagent Jones Reagent: 7-[2-Methoxyimino-2-{2-(2,2,2-trifluoroacetamido)-1,3-thiazol-4-yl}acetamido]-3-hydroxymethyl-3-cephem-4-carboxylic acid (syn isomer) (1.0 g.) was dissolved in a mixture of dimethylformamide (6 ml.) and acetone (30 ml.). Jones reagent (1.25 ml.), which was prepared from conc. sulfuric acid (0.28 ml.), chromium trioxide (0.33 g.) and water (0.9 ml.), was dropwise added thereto over 2 minutes with stirring and cooling at 0° to 2° C. After stirring for 20 minutes at the same temperature, the reaction mixture was poured into ice-water (50 ml.). After acetone was distilled off, the residue was twice extracted with ethyl acetate (50 ml.). The extracts were washed with…