Preparation of 2‐(1‐phenyl‐1H‐pyrazol‐5‐yl)benzenesulfonamides from polylithiated C(α),N‐phenylhydrazones and methyl 2‐(aminosulfonyl)benzoate

Select C(α), N‐phenylhydrazones were dilithiated in excess lithium diisopropylamide followed by condensation with methyl 2‐(aminosulfonyl)benzoate and acid cyclization to afford new pyrazol‐benzenesul‐fonamides, 2‐(1‐phenyl‐1H‐pyrazol‐5‐yl)benzenesulfonamides.     

On the linearity of regression

Summary A stochastic process X={X _t :tT| is called spherically generated if for each random vector , there exist a random vector Y=(Y₁,..., Y _m) with a spherical (radially symmetric) distribution and a matrix A such that X is distributed as AY. X is said to have the linear regression property if (X ₀¦X ₁,..., X _n) is a linear function of X ₁,..., X _n whenever the X _j's are elements of the linear span of X. It is shown that providing the linear span of X has dimension larger than two, then X has the linear regression property if and only if it is spherically generated. The class of symmetric stable processes which are spherically generated is shown to coincide with the class of socalled sub-Gaussian processes, characterizing those stable processes having the linear regression property.This research was supported by a grant from the University of Wisconsin-Milwaukee     

Capillary electrophoresis determination of diatrizoic acid and its impurities in diatrizoate radiopaque solutions

A capillary electrophoresis method has been developed for the separation and determination of diatrizoic acid (DTZA) and its four mono- and diiodo degradation products (2-iodo,4-iodo, 2,4-diiodo, and 2,6-diiodo-3,5-diacetamidobenzoic acid) in radio-paque solution for injection (RSI). DTZA and its degradants were assayed in suitable dilutions without pretreatment. Optimum conditions included the use of low-pressure sample injection (6 s), sample and standard solutions with a molarity less than that of the separation buffer, and adjustment of the buffer molarity to obtain a current of 50 A at a constant 15kV separation voltage. After each six runs or less, the inlet and outlet buffer were replaced with more buffer from the same batch. When the method was applied to a sample of SI levels of 5–10 mg/ml were found for each of the mono and diiodo impurities. The optimum method showed a precision (peak area measurement) in the range 1.7–7.2% RSD, depending on the concentration. A linear correlation coefficient of 0.997 was obtained over a DTZA concentration range of 5–60 mg/mL.     

Diffraction grating fabrication in Australia

The history of the fabrication, replication, and commercial applications of diffraction gratings in Australia is given, with particular reference to developments since the last comprehensive review of the subject was published in the mid-1970s.     

Synthesis and Crystal Structure Determination of Methyl 2-acetyl-5′-phenyl-2H-spiro[benzo[d]isothiazole-3,3′-pyrazole]-1,1-dioxide-2′(4′H)-carboxylate and Methyl 2-acetyl-5′-(2-thienyl)-2H-spiro[benzo[d]isothiazole-3,3′-pyrazole]-1,1-dioxide-2′(4′H)-carboxylate

Abstract  

Dilithiated C(α), N-carbomethoxyhydrazones were condensed with lithiated methyl 2-(aminosulfonyl)benzoate to afford intermediates that were isolated and not characterized but cyclized with acetic anhydride, which also resulted in N-acetylation. The X-ray crystal structure determinations of methyl 2-acetyl-5′-phenyl-2H-spiro[benzo[d]isothiazole-3,3′-pyrazole]-1,1-dioxide-2′(4′H)-carboxylate and methyl 2-acetyl-5′-(2-thienyl)-2H-spiro[benzo[d]isothiazole-3,3′-pyrazole]-1,1-dioxide-2′(4′H)-carboxylate products were a follow up for absorption spectra, and they confirmed their structures. Mechanistic intermediates to describe the reaction may include C-acylated intermediates that cyclize to spiro(N-benzoisothiazole dioxide-pyrazole) instead of N-carbomethoxypyrazole-ortho-benzenesulfonamides. Crystals of C₁₉H₁₇N₃O₅S 7 are monoclinic, P2₁/c, a = 11.899(2) ?, b = 17.562(4) ?, c = 9.484(2) ?, β = 111.03(3)°, Z = 4, V = 1849.9(6) ?³, R ₁ = 0.0857 and wR ₂ = 0.2216 for reflections with I > 2σ(I); crystals of C₁₇H₁₅N₃O₅S₂ 8 are orthorhombic, Pbca, a = 16.045(3) ?, b = 10.746(2) ?, c = 20.389(4) ?, Z = 8, V = 3516(1) ?³, R ₁ = 0.0841 and wR ₂ = 0.2179 for all reflections with I > 2σ(I).     

The preparation of 3,3a,4,5‐tetrahydronaphth[1,2‐c]isoxazoles from dilithiated 1‐tetralone oxime and select aromatic aldehydes

Dilithiated 1‐tetralone oxime was condensed with several electron enriched aromatic aldehydes, such as 4‐methoxybenzaldehyde or lithiated 4‐hydroxybenzaldehyde, followed by acid cyclization to new tetrahydronaphthisoxazoles, 3,3a,4,5‐tetrahydronaphth[1,2‐c]isoxazoles, with a trans geometry of the C₃‐H and C_3a‐H protons that was confirmed by X‐ray single crystal analysis.     

Binary bases of spaces of continuous functions

This paper addresses the question of density of binomials in C[a,b]. This seemingly innocuous question turns out to be equivalent in certain instances to the moment problem.