This paper describes a simple means for embedding a checksum within a FITS header, providing a mechanism for later verifying the integrity of the FITS le. The method uses ASCII coded 32-bit 1's complement arithmetic to force the checksum of each FITS HDU to zero. This technique requires no extension of the FITS standard to be used by any given project, in fact the technique may be used to zero ...

The second author’s ω, ∆, χ conjecture proposes that every graph satisties χ ≤ d 1 2 (∆ + 1 + ω)e. In this paper we prove that the conjecture holds for all claw-free graphs. Our approach uses the structure theorem of Chudnovsky and Seymour. Along the way we discuss a stronger local conjecture, and prove that it holds for claw-free graphs with a three-colourable complement. To prove our results ...

Epilepsy is a chronic neurological disorder characterized by recurrent seizure attacks which are caused by an abnormal electrical discharge in the brain. Currently, there is a need for improved medicinal agents to treat epilepsy, since the currently available drugs are effective only in 60-80% of epileptic patients. So the indirect type of molecular modeling study was carried out to find out th...

The base catalyzed intramolecular nucleophilic cyclization of 1-(2-bromobenzoyl)-3-(2-fluorophenyl)thiourea (1) in the presence of N,N-dimethyl formamide (DMF) afforded the 1-(3-fluorophenyl)-2-thioxo-2,3-dihydroquinazolin-4(1H)-one (2) by an intramolecular nucleophilic substitution SNAr mechanism. The structure was supported by the spectroscopic data and unambiguously confirmed by the single c...

A highly efficient and versatile synthetic approach to the synthesis of annelated quinazoline derivatives viz. 3,4,9,10a-tetraazaphenanthrenes 5 – 7, thiazolidinylquinazoline 9, 2,4,9,10a-tetraazaphenanthrene 11, quinazolino[4,3-b]quinazolin-8-one 12 and imidazoquinazolines 14a,b, 15. Also, a variety of pyrazolylquinazolines 19 – 21, pyrimidinylquinazolines 22a,b were obtained via a sequence of...

The paper describes industrially scalable synthesis and single crystal studies of 3-cyclopropyl3,4-dihydroquinazolin-2(1H)-one 4, a versatile intermediate in the synthesis of number of biologically active compounds. The target compound has been characterized by LC-MS, 1H NMR and IR. The crystal structure analysis shows that the title compound crystallizes in monoclinic class under the space gro...