RESEARCHES ON QUINAZOLINES. XXXIII. A NEW AND SENSITIVE INDICATOR FOR ACIDIMETRY AND ALKALIMETRY, AND FOR THE DETERMINATION OF HYDROGEN-ION CONCENTRATIONS BETWEEN THE LIMITS OF 6 AND 8 ON THE SORENSEN SCALE.¹

Abstract

MARSTON TAYLOR BOGERT A N D GEORGE SCATCHARD. and to the quinonoid interpretation of the cause of color in the triphenylmethane series in general. This applies in no lesser degree to the free triarylmethyl radicals themselves. In the solid state they are nearly all colorless or only pale yellow, but when they are dissolved in some solvent, like benzene, intensely colored solutions result. We must assume from the evidence presented in this paper that the radicals dissolve with a simultaneous partial transformation to the quinonoid state. ANN ARBOR, MICK [CONTRIBUTION FROM THE CHEMICAL LABORATORIES OF COLUMBIA UNIVERSITY, No. 267.1 TIVE INDICATOR FOR ACIDIMPTRY AND ALKALIMETRY, ION CONCENTRATIONS BETWEEN THE LIMITS OF 6 AND 8 ON THE SORENSEN SCALE.' Introductory. As a means of measuring hydrogen-ion concentration, the use of an indicator possesses the obvious advantage of convenience of operation, practically instantaneous readings and inexpensive apparatus. Ostwalds explanation3 of indicator action as due to an equilibrium between an ion of one color and an un-ionized molecule of another color (or colorless), has been quite generally abandoned in favor of the theory that an equilibrium exists between the two forms in both states4 RESEARCHES ON QUINAZOLINES. XXXIII. A NEW AND SENSI-AND FOR THE DETERMINATION OF HYDROGEN-BY MARSTON TAYLOR BOGBRT AND GEORGE SCATCHARD.%

Design, Synthesis, and Biological Evaluation of New Potential Unusual Modified Anticancer Immunomodulators for Possible Non-Teratogenic Quinazoline-Based Thalidomide Analogs

“…The sequence of the reactions for the synthesis of our target compounds is described in Schemes 1-3. Firstly, the starting material quinazoline-2,4(1H, 3H)-dione I was synthe sized according to the reported procedures [46,47] through the fusion of anthranilic acid with urea. The chlorination of compound I was achieved using phosphorous oxychlorid in the presence of TEA, affording 2,4dichloroquinazoline II [48].…”

“…They were within ± 0.4 of the theoretical values. Compounds I, II, III, IVa-d, Va-d, VI, VIII, X, and XVII were synthesized according to previously reported procedures [21,46,47,49,[52][53][54][59][60][61][62][63].…”

The Determination of Hydrogen Ions. An Elementary Treatise on the Hydrogen Electrode, Indicator and Supplementary Methods with an Indexed Bibliography on Applications.

“…These and numerous other indicators such as Dox's . (1915) phenol quinohnein, Scatchard and Bogert's (1916) di nitro benzoylene urea, and Rupp's (1915) syntheses in the methyl red series, present a wealth of material but little of which has been thoroughly worked over.…”

The Acid Catalyzed Cleavage of 4-Quinazolylmalonic Ester and Related Compounds to 4-Quinazolone

“…6,8-DinitrobenzoyIeneurea prepared from the above melted at 273-274°(dec.). Reported m.p., 274-275°( dec.) (28).…”