Anhydrous Ethereal Solution

Since the distribution ratio of hydrogen azide between the two solvents ether and water is approximately 7 1, ethereal solutions may be prepared by extraction of aqueous solutions with ether. However, the procedure used by Frost, Cothran, and Browne6 is preferable. 

Potassium, rubidium, and cesium azides are of particular interest, since they undergo thermal decomposition at higher temperatures with the formation of the free alkali metals and the evolution of nitrogen in accordance with the equation 

These azides may therefore be employed for the preparation of small quantities of very pure potassium, rubidium, or cesium.1 They have also been decomposed to obtain very pure nitrogen.2 

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The diazomethane-ether solution should be dry. If in doubt, it may be dried with A.R. potassium hydroxide pellets. The anhydrous ethereal solution may be stored in a smooth glass flask or bottle in a refrigerator for a week or so since slow decomposition occurs with hberation of gas, the containing vessel should be protected by a calcium chloride (or cotton wool) guard tube. 

Zinc, cyclopropane from 1,3-dichloropropane, 51, 58 Zinc, activated, 53, 88 Zinc chloride, anhydrous, ethereal solution, preparation of, 54, 54... 

The carbons were oxidized with oxygen at 420-450°. CH,N, was used in anhydrous etheric solution. Figures in bold face were obtained using ether saturated with water as... 

The free base thus obtained is extracted with toluene, the extract is dried over magnesium sulphate and to the anhydrous toluene solution is added an anhydrous ethereal solution of hydrogen chloride until the precipitation of the target compound is complete. This procedure yields 9.53 g (76.2% of the theoretical amount) of ethyl 10-(p-morpholylpropionyl)-phenthiazine-2-carbamate hydrochloride. After recrystallization from dichloroethane, the target compound melts at 189°C. (decomp.). 

The product of hydrolysis was placed in anhydrous ether solution and the mixture added to a suspension of freshly prepared sodamide in liquid ammonia in a weight ratio of about 2.28 product 25 ether 1.36 sodamide 100 ammonia. At -40°C no reaction appeared to take place other than the formation of the alkoxide of the starting material. On raising the temperature to -30°C, the reaction mixture turned a deep opaque purple which remained for the duration of the run. After two hours the reaction mixture was quenched with ammonium chloride. 

Formation of the Grignard reagent Magnesium reacts with an alkyl halide in an anhydrous ether solution. 

The dehalogenation is carried out in anhydrous ether solution under reflux with excess zinc. The ether-soluble zinc chloride is then precipitated by the addition of petroleum ether. The resulting solution may be used directly or distilled to obtain the pure ketene. 

When at least 2 equivalents of an aryl cyanate 9 are treated with one equivalent of ammonia in anhydrous ethereal solution, iminobiscarboximidates 10 can be isolated361,362 (cf. Houben-Weyl, Vol. E4, p 1073). Compounds 10 can be converted to 1,3,5-triazines by reaction with either a further equivalent of aryl cyanate, or with formylating reagents such as triethyl orthoformate.362 A direct synthesis of 1,3,5-triazines 11 from aryl cyanates and ammonium carbonate in aqueous solution has also been described.363... 

When they are prepared in anhydrous ethereal solution, the reaction is usually complete in 1-3 h at room temperature or after gentle warming.677 678 For preparation of benzoyl isocyanate, silver cyanate and benzoyl chloride were heated under reflux for 6 h in carbon tetrachloride.679 Older preparations, e.g., that of acetyl isocyanate,680 were made also without solvent but under cooling. 

II. Anhydrous Ether Solution Since the distribution of HNg between water and ether is approximately 1 7, one can extract an aqueous solution of HNg with ether. However, even in this case it is preferable to use a distillation method NaNg (30 g.) is dissolved in 100 ml. of water, 150 ml. of ether is added, and the mixture is placed in a 500-ml., round-bottom flask. The latter is equipped with an adapter fitted to a condenser, followed by a suitable ice-cooled receiver flask containing 100 ml. of ether. The round-bottom flask is also equipped with an addition funnel, the tip of which is Immersed in the liquid and through which 30 ml. of concentrated HgSO is slowly added. The bulk of the ether and HNg distill off during the addition of the HgSO. The remainder... 

Fe(CO)4l3 is obtained in anhydrous ether solution using a slight excess of Fe(CO>5 [the ether solution is 2M in Fe(CO)s and 0.5M in 13]. On evaporation, the compound separates in large, black crystals. Yield quantitative. 

The preparation proceeds in anhydrous etheral solution, using 50 ml. of ether/g. of Fel3 the air is displaced from the autoclave by evacuating and flushing with CO (which may be taken directly from a cylinder). While the yield is quantitative, the duration of the CO absorption depends on the surface/volume ratio in the solution. Thus, in xmagitated systems the reaction may occasionally take several days. 

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