Acetonitrile boiling point

The solvents used for liquid chromatography are the commoner ones such as water, acetonitrile, and methanol. For the reasons just stated, it is not possible to put them straight into the ion source without problems arising. On the other hand, the very viscous solvents that qualify as matrix material are of no use in liquid chromatography. Before the low-boiling-point eluant from the LC column is introduced into the ion source, it must be admixed with a high-boiling-point matrix... 

Removal of maleic and fumaric acids from the cmde malononitrile by fractional distillation is impractical because the boiling points differ only slightly. The impurities are therefore converted into high boiling compounds in a conventional reactor by means of a Diels-Alder reaction with a 1,3-diene. The volatile and nonvolatile by-products are finally removed by two vacuum distillations. The by-products are burned. The yield of malononitrile amounts to 66% based on cyanogen chloride or acetonitrile. 

Trichloro- and dichloromethane, ether, dioxane, benzene, toluene, chlorobenzene, acetonitrile, or even pyridine itself has been employed to carry out the one-pot syntheses. Tliese solvents allow straightforward preparation of the salts. The temperature range between 0° and 20°C is usually employed and the salts formed are sufficiently soluble. In the case of slow reactions, selection of a solvent with a higher boiling point is prohtable since thermal instability of the A -(l-haloalkyl)heteroarylium halides has not been reported. Addition of water or an aqueous solution of sodium acetate does not cause a rapid decomposition of the salts so that this constitutes a useful step in the optimization of some procedures. 

OS 14] [R 17] [no protocol[ Further studies related to the desymmetrization of thiorueas showed that for the diphenylthiourea/cydohexylamine system reasonable reaction rates and conversions were achieved [42, 85], It is notable that the temperatures of up to 91°C applied slightly exceed the boiling point of the solvent acetonitrile. 

Solvents for PTC should be nonhydroxylic and immiscible with water. CHCI3, CH2CI2, chlorobenzene, toluene, and acetonitrile are commonly employed. If the reactant is liquid, extra solvent is not required. Although chloroform and methylene chloride are favourable from a chemistry point of view, engineering considerations often lead to the choice of chlorobenzene (and toluene) because of their lower solubility in water and higher boiling point. 

Methyl hypofluorite (McOF) and tert-butyl hypofluorite (f-BuOF) have been prepared by the reaction of elemental fluorine with methanol and tert-butyl alcohol, respectively, in acetonitrile or propionitrile at — 78 °C. Methyl hypofluorite can be removed from the reaction mixture in a stream of nitrogen and purified by fractional distillation the liquid compound has a freezing point of — 142 C, is moderately long-lived, but explodes upon rapid warming.is tert-Butyl hypofluorite melts around — 94 °C and has an extrapolated boiling point of about 40 C the neat reagent must be regarded as a substance the hazards of which have not been fully defined.16... 

Uses, Because of its good solvency and relatively low boiling point, acetonitrile is used widely as a recoverable reaction medium, particularly for the preparation of pharmaceuticals. Its largest use is for the separation of butadiene from C4 hydrocarbons by extractive distillation. 

Stull1 presents the vapor pressure of HCN from the freezing point to the critical tempcrulurc. Data arc available up to the boiling point for the other three compounds., J5,4,UW Data for acetonitrile have been correlated for slightly above... 

The heat of vaporization at the boiling point has been determined for IICN and acetonitrile.1- 5, 4i-uv The estimation technique of Velcrowas used to calculate the heat of vaporization of propionitrile and butronitrile The boiling point data were extended over a wide temperature range by the Kharbandu nomograph of the Watson equation." The overall error is probably 5r or less. 

Acetonitrile (mp, -45°C bp, 81°C) is a colorless liquid with a mild odor. Because of its good solvent properties for many organic and inorganic compounds and its relatively low boiling point,... 

To 166.0 g (0.41 mol) of the methiodide of l-p-chlorophenyl-2,5-dimethyl-3-dimethylaminomethylpyrrole in 600 ml of dimethylsulfoxide, 66.6 g of sodium cyanide are added and the mixture is heated to 100°C with stirring and under a nitrogen stream for 3.5 h. After cooling, the mixture is poured into 1500 ml of water and extracted with ether. The ethereal phase is washed with water, dried on MgS04 and evaporated. The residue is vacuum stripped 62.1 g of a yellow oil are thus obtained, which rapidly solidifies and which is recrystallized from aqueous methanol, 57.4 g (yield 56%) of l-p-chlorophenyl-2,5-dimethyl-3-pyrrole acetonitrile are obtained, melting point 86°-88°C, boiling point 158°-161°C (0.4 mm). 

PS-PPI13. A combination of PS-PPI13 and CCI3CN not only facilitated the formation of intermediate 1,2-diacylhydrazides by in situ conversion of carboxylic acids to acid chlorides, but also assisted subsequent cyclization to 1,3,4-oxadiazoles. The workup comprised simple filtration of the resin and evaporation of solvents, followed by flash chromatography. The cyclocondensation occurred within 20 min when heated in acetonitrile by microwaves in a sealed vial at 150 °C (68 °C above the boiling point) [92] (Scheme 32). 

A small library of di- and trisubstituted pyrimidines was prepared by condensation of amidines and guanidines with a range of alkynones. The reaction could be performed under conventional conditions (reflux in acetonitrile, ca. 82 °C), albeit 2 hours was required for the reaction to go to completion. Microwave dielectric heating in sealed vessels at 120 °C (ca. 38 °C above the boiling point of acetonitrile) diminished the reaction time to 40 min [120,121] (Scheme 46). 

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