Reaction of 4-hydroxycoumarin with arylglyoxals and ureas

Long- and intermediate-range interaction between two ground state hydrogen atoms

“…I n the variational calculation of the energy for the B state of H, a generalized James-Coolidge type wave function was employed identical with that used previously for this state [6]. The wave function was assumed in the form with where 5 and 7 denote the elliptic coordinates, p = rl,/R, rI2 and R denote the interelectronic and internuclear distances, respectively, and c, , u, ii, , 9 and fi are variational parameters.…”

“…The computations were carried out in double precision arithmetic on the IBM 370/165 computer at the University of Florida. Due to a higher precision than that of the previous computations [6] a more extended basis set could now be used. However, in the case of longer expansions problems caused by almost linear dependencies, by loss of accuracy, etc., have still been encountered.…”

“…I t * Permanent address. has been argued by Stwalley [5j that the previous most accurate variational energy for this state [6] could still be improved by as much as 80 cm-1 at R = 12 a.u. and progressively less for smaller internuclear separations.…”

Multicomponent one‐pot synthesis of novel imidazole‐2‐thione derivatives containing allomaltol fragment

“…A convenient approach to the synthesis of hydroxyl‐containing terarylenes is based on the application of the multicomponent reactions (MCRs) methodology. [ 15–26 ] The high atom economy coupled with a minimum number of chemical steps and the absence of complex catalysts are obvious advantages of MCRs. [ 27–28 ] Moreover, the MCRs approach is widely used for the synthesis of various heterocyclic systems.…”

N,N′-Dimethyl Urea

“…J) Kolos and co-workers synthesized 4-aryl-5-(4-hydroxy-2-oxo-2H-chromen-3-yl)-1H-imidazol-2(3H)-ones by one-pot condensation of 4-hydroxycoumarin with arylglyoxals and DMU in ethanol in the presence of a catalytic amount of acetic acid within a short time (15-50 min) 13. …”