摘要:

AbstractA kinetic study of the first step in the reaction of phenol and formaldehyde, the formation ofortho‐andpara‐hydroxymethylphenol, is described.It is found that when using NaOH or KOH as a catalyst under weakly alkaline conditions (pH = 8.5‐10.5) at 30° C, thepara‐position in the phenolic nucleus is nearly twice as reactive as theortho‐position (theortho/pararatio being 1.10). Interesting effects are observed in more strongly alkaline media (pH = 10.5‐13.5),inter aliaa sharp decrease in theortho/pararatio with increasing value of pH.When other hydroxides are used, an increasing value of theortho/pararatio is found with the hydroxides of K, Na, Li, Ba, Sr, Ca and Mg, respectively. Probably chelate formation occurs in the transition state forortho

ISSN:0165-0513    

DOI:10.1002/recl.19590781102

出版商:WILEY‐VCH Verlag    

年代:1959

数据来源: WILEY

摘要:

AbstractOxidation of petroselinic or petroselaidic acid with neutral potassium permanganate gave mainly a mixture of two structurally isomeric hydroxy‐ketoacids, characterised as 7‐hydroxy‐6‐ketostearic acid, m.p. 77.5‐78.5 and 6‐hydroxy‐7‐ketostearic acid, m.p. 74.5‐75.0°. Lead tetraacetate is shown here to be an effective cleavage reagent for 1,2‐ketols and 1,2‐diketones. The oxidation of thecis‐andtrans‐6‐octadecenoic acids with hydrogen peroxide with and without catalyst (OsO4) has been studied. Thecis‐hydroxylation of petroselinic and petrose

ISSN:0165-0513    

DOI:10.1002/recl.19590781103

出版商:WILEY‐VCH Verlag    

年代:1959

数据来源: WILEY

ISSN:0165-0513    

DOI:10.1002/recl.19590781104

出版商:WILEY‐VCH Verlag    

年代:1959

数据来源: WILEY

ISSN:0165-0513    

DOI:10.1002/recl.19590781105

出版商:WILEY‐VCH Verlag    

年代:1959

数据来源: WILEY

ISSN:0165-0513    

DOI:10.1002/recl.19590781106

出版商:WILEY‐VCH Verlag    

年代:1959

数据来源: WILEY

摘要:

AbstractThe percentage of orotic acid, sensitive to ultraviolet light, has been found to depend on the concentration of oxygen in solution. Diminishing this concentration by bubbling through nitrogen or hydrogen, the sensitivity increases from 14 % to 37 %. Saturation of the solution with oxygen leads to protection (instead of 14 % an irreversible loss of 7%). One of the reactions, shown by uracil on irradiation (“the first irreversible reaction”) also exhibits this relationship. The possibility of an intermediate triplet state is propo

ISSN:0165-0513    

DOI:10.1002/recl.19590781107

出版商:WILEY‐VCH Verlag    

年代:1959

数据来源: WILEY

摘要:

AbstractThe extent to which the extinction of thymine and orotic acid decreases on irradiation by U.V. light depends on the environmental conditions. Successive irradiations in different milieus ultimately lead to a degree of conversion which is wholly determined by the conditions during thelastirradiation. Consequently it is possible to revert the substances that seem to have disappeared to the original products.

ISSN:0165-0513    

DOI:10.1002/recl.19590781108

出版商:WILEY‐VCH Verlag    

年代:1959

数据来源: WILEY

ISSN:0165-0513    

DOI:10.1002/recl.19590781109

出版商:WILEY‐VCH Verlag    

年代:1959

数据来源: WILEY

摘要:

AbstractThe polarography of manganate has been studied in sodium hydroxide solutions as supporting electrolyte, particularly as regards the effects of alkalinity, manganate concentration and the presence of formic acid. At alkalinities less than 1MNaOH reduction passes to Mn+2and then to Mn0along two main waves. In 1MNaOH reduction yields Mn+3and then Mn0. Polarograms in 0.1, 0.5 and 1Malkali can be used for the determination of manganate in 2.5 × 10−4to 2 × 10−3Msolu

ISSN:0165-0513    

DOI:10.1002/recl.19590781110

出版商:WILEY‐VCH Verlag    

年代:1959

数据来源: WILEY

摘要:

AbstractThe method described is supplementary to and an extension of a method previously described for the analysis of detergents by means of ion‐exchangers.The A.D. acid(i.e., active detergent in acid form) adsorbed on the Dowex‐1, X2, [Ac−] ion‐exchanger can be quantitatively eluted with a solution of sodium acetate. After conversion of the sodium salts into the corresponding acids, the A.D. acid and acetic acid can be separated by ion‐exclusion. Fatty acids are adsorbed on Dowex‐1, X2, [OH−] and can be eluted with KOH‐solution.Experiments with dodecylsulphuric acid, dodecylsulphonic acid and acyltaurines are described, but it is possible that the ion‐exclusion technique can be extended to other detergents.Any urea present is adsorbed in alcoholic medium on D

ISSN:0165-0513    

DOI:10.1002/recl.19590781111

出版商:WILEY‐VCH Verlag    

年代:1959

数据来源: WILEY