Synthesis of Bis-ureas from Bis(o-nitrophenyl) Carbonate

Abstract

A general method for the preparation of bis-ureas from bis(o-nitrophenyl) carbonate has been developed. Directional urea synthesis is achieved by sequential amine addition to bis(o-nitrophenyl) carbonate in two steps: in the first step bis(o-nitrophenyl) carbonate is reacted with benzylamine to form benzyl-o-nitrophenyl carbamate; in the second step the carbamate is reacted with a variety of diamines in toluene to yield bis-ureas.

Transmembrane Transport of Inorganic Phosphate by a Strapped Calix[4]pyrrole

“…Strap 8 reacted in neat pyrrole to form precursor 9 , which was subjected to a condensation reaction with acetone to afford strapped calix[4]­pyrrole receptor 1 in a moderate yield. Reported compounds 2 and 3 (Figure c) were synthesized as control compounds, representing either the strap ( 2 ) or the calix[4]­pyrrole base ( 3 ) components of receptor 1 (Scheme S1).…”

“…Receptor 1 was found to be active as a H 2 PO 4 − /Cl − antiporter, a H 2 PO 4 − uniporter, and a Cs + H 2 PO 4 − symporter. The higher transport activity observed in the 31 P NMR assay at pH 5 compared to that at pH 7 and 8 indicates that phosphate is mainly transported in the form of H 2 PO 4 − . This work represents a breakthrough for the…”

Transmembrane Transport of Phosphate by a Strapped Calix[4]pyrrole

“…Strap 8 reacted in neat pyrrole to form precursor 9, which was subjected to a condensation reaction with acetone to afford strapped calix [4]pyrrole receptor 1 in moderate yield. Reported compounds 2 31 and 3 32 (Figure 1c) were synthesised as control compounds, representing either the strap (2) or the calix [4]pyrrole base (3) components of receptor 1 (Scheme S1).…”