A compound that is involved in the biosynthesis of the drosopterin eye pigments has been isolated from the heads of Drosophila melanogaster. Analyses of this compound by chemical, mass spectral, and proton nuclear magnetic resonance techniques in conjunction with biochemical considerations provide evidence for the structure 2-amino-4-oxo-6-acetyl-7,8-dihydro-3H,9H-pyrimido[4,5-b][1,4]diazepine ...

W. S. H am am a Chemistry D epartm ent, Faculty of Science, M ansoura University, M ansoura, Egypt R eprint requests to Dr. W. S. H am am a. E-mail: Sinfac@ mum.mans.eun.eg Z. Naturforsch. 55b, 443-447 (2000); received January 25, 2000 6-Am inouracil, M annich Reaction, Pyrimido[4,5-d]pyrim idine The reaction of 6-am inouracil 1 with form aldehyde and secondary amines in ethanol at room tem per...

The iron-catalyzed oxidative C–C homocoupling of diarylamines affords 2,2ʹ-bis(arylamino)-1,1ʹ-biaryls which represent crucial synthetic building blocks for an access to a range sevenmembered heterocyclic ring systems. Reaction with paraformaldehyde, diphenyl carbonate, and sulfite as efficient 1,1ʹ-dielectrophiles led dibenzo[d,f][1,3]diazepines, dibenzo[d,f][1,3]diazepinones, dibenzo[c,e][1,2...

Olanzapine (Olz) is one of the most effective antipsychotic drugs commonly used for treating schizophrenia. Unfortunately, Olz administration is associated with severe weight gain and metabolic disturbances. Both patients and clinicians are highly interested in the development of new antipsychotics which are as effective as atypical antipsychotics but which have a lower propensity to induce met...

The use of benzodiazepines for the treatment of anxiety disorders has long been controversial. It has divided doctors into those who emphasise problems with their use and avoid them, and those who continue to prescribe them, albeit reluctantly and even secretively. Complicating matters further, some doctors express one opinion about benzo­ diazepines publicly and quite the opposite view private...

In the current study, a magnetic inorganic–organic nanohybrid material (HPA/TPI-Fe3O4) was produced and used as an efficient, highly recyclable and eco-friendly catalyst for the one-pot and multicomponent synthesis of 3,4-dihydroquinoxalin-2-amine, diazepine-tetrazole and benzodiazepine-2-carboxamide derivatives with high yields and in a short range of time (20–35 min)...