Acid chlorides infrared spectra

B) Acylation of 6-Aminopenicillanic Acid To a solution of the aryl halocarbonyl ketene (0.1 mol) in methylene chloride (sufficient to provide a clear solution and generally from about 5 to 10 ml per gram of ketene) there is added the proper alcohol RjOH (0.1 mol), in this case 5-indanyl alcohol. The reaction mixture is maintained under an atmosphere of nitrogen and stirred for a period of from 20 minutes to 3 hours, care being taken to exclude moisture. The temperature may range from about -70° to about -20°C. The infrared spectrum of the mixture is then taken to determine and confirm the presence of the ketene ester. A solution of 6-aminopenicillanic acid-triethylamine salt (0.1 mol) in methylene chloride (50 ml) is added and the mixture stirred at -70° to -20°C for 10 minutes. The cooling bath is then removed and the reaction mixture stirred continuously and allowed to warm to room temperature. 

Infrared radiation, electromagnetic spectrum and, 419, 422 energy of. 422 frequencies of, 422 wavelengths of, 422 Infrared spectroscopy, 422-431 acid anhydrides, 822-823 acid chlorides, 822-823 alcohols. 428, 632-633 aldehydes, 428. 730-731 alkanes, 426-427 alkenes, 427 alkynes, 427 amides. 822-823 amines, 428, 952 ammonium salts, 952-953 aromatic compound, 427-428, 534 bond stretching in, 422... 

To a solution of 2.00 grams (0.00454 mole) of K[Cr(HO-A)2] in 200 ml. of water, cooled to 6° C., were added 12.8 grams of benzoyl chloride and a solution of 2.00 grams of potassium bicarbonate in 20 ml. of water. This mixture was stirred in an ice bath for 30 minutes and then for an additional hour out of the bath. The solution was acidified with concentrated nitric acid, and then filtered to remove benzoic acid. From the filtrate only starting material (infrared spectrum ) and its decomposition products could be isolated. 

In 1994, Buzek et al. (109) reported that the allyl cation could be prepared from a variety of halide precursors, e.g., allyl chloride or cyclopropyl bromide, on SbF5 at cryogenic temperature, based on the infrared spectrum of the products. Those workers challenged BGW s claim of the persistent allyl cation based on the discrepancy between the isotropic 13C shift in the zeolite and that calculated at MP2/6-31G. This was one of the first examples of the use of chemical shift calculations to interpret (and in this case challenge) an NMR study of a species on a solid acid. 

With these compounds the presence of the halogen will have been detected in the tests for elements. Most acid halides undergo ready hydrolysis with water to give an acidic solution and the halide ion produced may be detected and confirmed with silver nitrate solution. The characteristic carbonyl adsorption at about 1800 cm -1 in the infrared spectrum will be apparent. Acid chlorides may be converted into esters as a confirmatory test to 1 ml of absolute ethanol in a dry test tube add 1 ml of the acid chloride dropwise (use a dropper pipette keep the mixture cool and note whether any hydrogen chloride gas is evolved). Pour into 2 ml of saturated salt solution and observe the formation of an upper layer of ester note the odour of the ester. Acid chlorides are normally characterised by direct conversion into carboxylic acid derivatives (e.g. substituted amides) or into the carboxylic acid if the latter is a solid (see Section 9.6.16, p. 1265). 

The compound is soluble in acetone, chloroform, methylene chloride, and nitromethane. It is insoluble in alkanes and cold water and stable toward water in the cold but gives an acidic solution when boiled with water. The infrared spectrum shows a single band at 2510 cm.-1, about 50 cm.-1 higher wave number than in the monobromo compound. The nB spectrum gives a doublet 18.9 p.p.m. upfield from trimethyl borate Jb-h = 155 Hz. The proton spectrum in methylene chloride shows a sharp singlet at 2.91 p.p.m. downfield from external tetramethylsilane and 0.20 p.p.m. farther downfield than the monobromo compound. Boron-attached hydrogens are not detectable. 

Infrared spectral analysis9 is employed as a check for other impurities which might be present in the molybdenum(IV) chloride. Molybdenum oxychlorides can be easily identified by their characteristic absorptions in the 900-1000-em.-1 region, which is typical of Mo—O groups. In addition, an examination of the far infrared spectrum should show only the characteristic bands of molybdenum(IV) chloride at 404, 350, and 268 cm.-1. These can be distinguished from those of other molybdenum halide species. A test for the presence of molybdenum (III) chloride, which often occurs as a side product in other preparations of molybdenum(IV) chloride, is treatment with 6 N hydrochloric acid. Complete solubility indicates the absence of this chloride. 

Considerably better results are obtained with copolymers of vinyl chloride and lead undecylenate. The lead salt of undecylenic acid, (CH2=CH—(CH2)g—COO)2Pb, can be copolymerized by free radicals in bulk or in methanol solution. The composition of the resulting polymer has been determined by infrared spectroscopy (4). Figure 5 shows an infrared spectrum of a film of homopolymeric PVC and of a copolymer obtained from vinyl chloride and lead undecylenate. At wavenumbers... 

Acid chloride—olefin addition and Friedel-Crafts cyclization A previous procedure was improved by use of methylene chloride as solvent rather than carbon disulfide. To check the progress of the reaction, one can quench a 2 3-ml. aliquot with water in a test tube, separate and dry the organic phase, and evaporate. The infrared spectrum will show disappearance of the acid chloride carbonyl band at 5.6(1 /j and appearance of the... 

Imidodisulfuryl fluoride is a colorless liquid, b.p. 170°, m.p. 17°. It behaves as a weak acid in water, in w-hich it is stable, and undergoes slow hydrolysis in alkaline solution. The infrared spectrum of imidodisulfuryl fluoride obtained using silver chloride plates (it reacts with sodium chloride) contains bands at 3311(m), 1471(vs), 1337(w), 1248(w), 1217(vs), 923(s), 893(m), and 832(s) cm. . The n.m.r. spectrum of imidodisulfuryl fluoride consists of a single band at —58.5 p.p.m. (from CC1 F), and the proton spectrum consists of a single band at —8.60 p.p.m. (from TMS). 

The infrared spectrum of phenoxymethyl penicillin (free acid) is number 88 in Hayden s compilation of spectra measured on a Perkin-Elmer Model 21 sodium chloride prism spectrophotometer. Infrared spectra of fourteen penicillins in the 1580 to 1880 cm-1 region are discussed by Ovechkin4. Figure 1 is the spectrum of the Squibb Primary Reference Substance of potassium phenoxymethyl penicillin recorded as a potassium bromide... 

The trans-fused octahydrobenzo[g]quinoline (60) is formed when the related 2-benzylpiperidine-3-carboxylic acid is heated in polyphosphoric acid. The 5-carbonyl group in the product is reduced to a metl lene group by lithium aluminium hydride-aluminium chloride (J.G. Cannon et dl. J. med. Chem., 1984, 190). The stereochanical assignment is based on the strong absorption at 2780 cm in the infrared spectrum of (60) and the large (65 Hz) chemical shift difference exhibited by the benzyl... 

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