摘要:

levo-2,3-Butanediol will condense with ethyl acetoacetate in the presence of hydrochloric acid to give the ethyl ester oflevo-2,4,5-trimethyl-2-carboxymethyl-1,3-dioxacyclopentane (I) (yield 48%) from which the free acid may be obtained. Ifp-toluenesulphonic acid is used as the catalyst and the condensation is carried out in boiling butanol with continuous removal of water, the butyl ester of (I) is obtained (yield 87%). Compounds described for the first time arelevo-,dl-, andmeso-2,4,5-trimethyl-2-carboxymethyl-1,3-dioxacyclopentanes, theirn-butyl andp-bromophenacyl esters (melting points 74.5°, 76°, and 76 °C., respectively) and the ethyl ester of thelevo-isomer.

ISSN:1923-4287    

DOI:10.1139/cjr47b-049

出版商:NRC Research Press    

年代:1947

数据来源: NRC

摘要:

Cyanogen chloride reacts quantitatively with water in the presence of hydrochloric acid according to the equation: CNCl + 2H2O → CO2 + NH4Cl. As the percentage of hydrochloric acid is reduced towards zero, the rate of hydrolysis at 30 °C. becomes exceedingly slow. The rate of hydrolysis, as indicated by the pressure increase, shows an increase with time which is particularly marked when the concentration of hydrogen chloride is less than 1%. This apparent autocatalytic effect is not due to the accumulation of solid ammonium chloride. A polymerization reaction, the rate of which is increased by the addition of dry hydrogen chloride, proceeds simultaneously with the hydrolysis reaction. Pure cyanogen chloride shows little or no tendency to polymerize at 30 °C. Carbon dioxide has been shown to be quite soluble in liquid cyanogen chloride and an explanation has been suggested for the form of the pressure vs. time curves obtained in studying the acid catalyzed hydrolysis and polymerization of cyanogen chloride.

ISSN:1923-4287    

DOI:10.1139/cjr47b-050

出版商:NRC Research Press    

年代:1947

数据来源: NRC

摘要:

The adsorptions of acetic, propionic, butyric, and valeric acids from aqueous solutions on a series of coconut charcoals of different degrees of activation were determined. For purposes of interpretation the numbers of millimoles adsorbed per gram of charcoal were compared for pairs of acids. Unimolecular adsorption of the acids is indicated. Surface areas of the charcoal series were estimated. They range from 130 to 625 sq. m. per gm. of charcoal, depending on the adsorbate used and the degree of activation of the charcoal. Some insight into the activation process is given.

ISSN:1923-4287    

DOI:10.1139/cjr47b-051

出版商:NRC Research Press    

年代:1947

数据来源: NRC

摘要:

A method is described for the photometric determination of amounts of calcium ranging from 0.04 to 0.16 mgm. The calcium is precipitated as the oxalate. The latter is converted to the carbonate by heating at 475° to 500 °C. for one hour. The carbonate is dissolved in 1 ml. of 0.01 Nhydrochloric acid. The excess acid is allowed to liberate iodine by reacting with potassium iodate and potassium iodide. The absorption of the iodine solution is measured by use of an Evelyn colorimeter, and the calcium originally present in the sample is determined from calibration data.

ISSN:1923-4287    

DOI:10.1139/cjr47b-052

出版商:NRC Research Press    

年代:1947

数据来源: NRC

摘要:

Smoke chamber studies have been made of the ageing of ammonium chloride smokes under various controlled degrees of turbulent air motion as well as in still air. The changes in mass concentration and particle number were followed for 5.5 hr. under each set of conditions, and some data on particle size distribution were obtained. The logarithm of the mass concentration was found to vary linearly with time under all conditions. None of the particle number data lent themselves to interpretation on the basis adopted by previous workers. They were described quantitatively by equations developed from general postulates which take into account loss to various surfaces. The equations permitted analytical separation of coagulation and surface effects, and the constant descriptive of the latter was closely related to that associated with mass loss. The coagulation constant for still air was found to be only slightly greater than the ideal Smoluchowski value. A description was obtained of the manner in which the various constants increased with the degree of air motion.

ISSN:1923-4287    

DOI:10.1139/cjr47b-053

出版商:NRC Research Press    

年代:1947

数据来源: NRC

摘要:

An acetyl derivative of heparin corresponding to one mole of acetyl per four hexose units has been prepared by passing ketene through a suspension of heparin in acetone. The derivative possesses the same biological activity as the original heparin. It can be deacetylated in neutral solutions without loss of activity by raised temperatures, and like heparin, it is inactivated in acid solution.

ISSN:1923-4287    

DOI:10.1139/cjr47b-054

出版商:NRC Research Press    

年代:1947

数据来源: NRC

摘要:

The freezing point diagram has been plotted for mixtures of acetic acid and urotropine containing 0 to 42% urotropine. Formation of a solid compound melting at 24.8 °C., and having the approximate composition (C6H12N4)3∙(C2H4O2)13is indicated. Repeated purification of the materials failed to shift the curve maximum to the expected ratio of 1 mole of urotropine to 4 moles of acetic aci

ISSN:1923-4287    

DOI:10.1139/cjr47b-055

出版商:NRC Research Press    

年代:1947

数据来源: NRC

摘要:

The Raman spectrum of a solution of urotropine in acetic acid (1 mole in 4) has been measured. The results are interpreted as indicating partial combination of the two in the liquid state. The presence of ammonium nitrate in amounts up to 1% caused no observable change in the Raman spectrum. Increasing the temperature of the solution containing ammonium nitrate to 50° to 60 °C. resulted only in a uniform darkening of the lines.

ISSN:1923-4287    

DOI:10.1139/cjr47b-056

出版商:NRC Research Press    

年代:1947

数据来源: NRC

摘要:

Kuhn and L'Orsa's method for estimating terminal methyl and similar groups was based on the recovery of the acetic acid formed when such units were oxidized with hot concentrated chromic acid solution. The method has now been reduced to the semimicro scale and refined to the point where good analyses for acetyl, ethylidene, ethoxy, and α-hydroxyethyl groups in a variety of substances are obtained. Acetylated triphenylmethyl cellulose ethers, which do not seem amenable to customary acetyl analyses, give good results by the present procedure.

ISSN:1923-4287    

DOI:10.1139/cjr47b-057

出版商:NRC Research Press    

年代:1947

数据来源: NRC