Simultaneous comparison of δ31P and 1JPN for the assignment of E/Z-stereochemistry of the phosphorus-nitrogen double bond in iminophosphines R-P=N-R′

 The analysis of ³¹P and ¹⁵N NMR data of a series of 40 iminophosphines R-P=N-R′ reveals that the E/Z-stereochemistry of the PN double bond can be predicted on the basis of a simultaneous comparison of the values of δ³¹P and ¹J_PN. Received: 31 May 1996/Revised: 2 July 1996/Accepted: 5 July 1996     

Synthesen in der Naphthalinreihe: Methoxylierte Tetralone und Naphthole

Ohne ZusammenfassungHerrn Prof. Dr.A. Franke in aufrichtiger Verehrung zum 80. Geburtstag gewidmet.     

Meldrum's acid and its analogs

2-Substituted or 2,2-disubstituted 4,6-dioxo-1,3-dioxanes, which are analogs of Meldrum's acid and were obtained by reaction of malonic acid with acetic anhydride and the appropriate carbonyl compound in the presence of sulfuric acid, exist in solution preferably in a single form according to the PMR and ¹³C NMR spectral data. Fluctuation of the CH₂ group is not observed. The mass spectra are characteristic and are distinguished by splitting out of the carbonyl compound from the molecular ion or successive splitting out of CO₂ and ketene molecules. The Meldrum acid analogs do not affect plant growth but have a depressive effect on the central nervous system of animals and low toxicity.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1482–1486, November, 1975.     

Synthesis and polymerization of N-vinylindole

The reaction of indole with acetylene under pressure is investigated. It is shown that under the action of KOH in aqueous dioxane at 220° C, N-vinylindole C₁₀H₉N is formed in 66% yield, and that this compound undergoes free radical and cationic polymerization.     

Hydrolysis study of organic acid anhydrides by differential thermal analysis-I Pyromellitic dianhydride

A technique for following the hydrolysis of pyromellitic acid dianhydride (PMDA) by differential thermal analysis (DTA) is described. On exposure of PMDA to moisture, an endothennic peak is initiated between 190 and 200 degrees . As the degree of hydrolysis increases, this peak becomes more intense and shifts to higher temperatures. The formation of pyromellitic acid (PMA) during the hydrolysis of PMDA can be determined qualitatively by DTA.     

The crystal structure of iododimethyl(trimethylamine)aluminum

The crystal structure of iododimethyl(trimethylamine)aluminium has been determined from single-crystal X-ray diffraction data collected by counter methods. I(CH₃)₂Al · N(CH₃)₃ crystallizes in the othorhombic space group Pnma with cell dimensions a=12.59(1), b=10.75(1), c=7.58(1)å, and p_calc=1.58 g·cm^?3 for Z=4. Least-squares refinement gave a final weighted R Value of 0.071 for 574 independet observed reflections. Each monomeric molecule lies on a crystallographic mirror plane with the trimethylamine and iododimethylaliminium groups in a staggered configuration about the aluminum  nitrogen bond.