New Synthesis of 4-Nintrobenzamide

The Problem of Phase Transitions in PZT Based Solid Solutions, Pb(Mg 1/3 Nb 2/3 )O 3, Pb(In 1/2 Nb 1/2 )O 3 and "Relaxor Ferroelectricity." 2. Analysis of Experimental Results and Phase Diagrams for Pb(Mg 1/3 Nb 2/3 )O 3, Pb(B′ 1/2 B′′ 1/2 )O 3

“…The boundary concentration region which separates those of FE and AFE states of the phase Y-T diagram is located in the vicinity of 16-20 mol% of PbTiO 3 . The results of X-ray and dielectrical investigations of the samples of this solid solution system presented in [8] corroborate the model proposed in this section which relates the degree of diffusion (and the so-called relaxor behavior) to the interstability of FE and AFE states. In Pb(Lu 1/2 Nb 1/2 )O 3 PE PT is clear.…”

“…With further growth of lead titanate content PE PT Downloaded by [Bibliothèques de l'Université de Montréal] at 11:30 03 December 2014 becomes clear again ( Fig. 6 and 8 in [8]). According to X-ray analysis data, the degree of composition ordering Lu-and Nb-ions constantly diminishes as the concentration of PbTiO 3 in the solid solution increases.…”

“…1a) which actually is the hysteresis region of FE-AFE transitions. Analogous phase diagrams take place at the substitution of titanium by the complexes (Lu 1/2 Nb 1/2 ) or (Yb 1/2 Nb 1/2 ) [8][9][10]. They are also presented in Fig.…”

Catalytic amide formation from non-activated carboxylic acids and amines

“…30 Shteinberg demonstrated that boric acid in combination with PEG-400 are effective in the catalytic amidation of 4-nitrobenzoic acid using gaseous ammonia. 57 Interestingly, neither boric acid nor PEG-400 was catalytically active alone in the absence of the other component. Under optimized conditions, 35 using 2 mol% boric acid and 1 mol% PEG-400 in refluxing 1,2,4-trichlorobenzene (bp 170-175 ºC), 4-nitrobenzamide was formed in 92% yield after 10 hours (Scheme 14).…”

“…The first report was published by Shteinberg in 2003, who used Ti(OBu) 4 in combination with 45 PEG-400 for the reaction of 4-nitrobenzoic acid and ammonia. 57 The amide was formed in 90% yield using 2 mol% of the titanium complex and 0.9 mol% PEG-400 in refluxing trichlorobenzene (Scheme 22). Neither Ti(OBu) 4 nor PEG-400 were active as catalysts on their own.…”