The reaction of quinazolones with POCl3 to form the corresponding chloroquinazolines occurs in two distinct stages, which can be separated through appropriate temperature control. An initial phosphorylation reaction occurs readily under basic conditions (R3N, aq pKa > 9) at t < 25 °C to give a variety of phosphorylated intermediates. Pseudodimer formation, arising from reaction between phosphorylated intermediates and unreacted quinazolone, is completely suppressed at these temperatures, provided the system remains basic throughout the POCl3addition. Clean turnover of phosphorylated quinazolones to the corresponding chloroquinazoline is then achieved by heating to 70−90 °C. (N)- and (O)-phosphorylated intermediates, involving multiple substitution at phosphorus, have been identified and their reactions monitored using a combination of 1H, 31P, and 19F NMR. Kinetic analysis of the reaction profiles suggest that the various intermediates react with both Cl− and Cl2P(O)O−, but product formation arises exclus...
Euan A. Arnott; Lai C. Chan; Brian G. Cox; Brian Meyrick; Andy Phillips
In this Perspective, we present an overview of recent fundamental studies on the nature of the interaction between individual metal atoms and metal clusters and the conjugated surfaces of graphene and carbon nanotube with a particular focus on the electronic structure and chemical bonding a ... more
The first [ECE]Ni(II) pincer complexes with E = SiII and E = GeII metallylene donor arms were synthesized via C–X (X = H, Br) oxidative addition, starting from the corresponding [EC(X)E] ligands. These novel complexes were fully characterized (NMR, MS, and XRD) and used as catalyst for Ni-c ... more
Rohm and Haas Powder Coatings is delighted to announce that its Reading, Pennsylvania, facility is the first site in the world to receive the RCMS® Site Certification awarded by the American Chemical Council (ACC).
When Raj Gupta, Chairman and CEO of Rohm and Haas Company, became Chairman ... more