Epoxidation of 2-azabicyclo[2.2.1]hept-5-en-3-one

Epoxidation of 2-azabicyclo[2.2.1]hept-5-en-3-one has been performed in high yield with potassium hydrogen persulfate at pH 6, ¹H nmr data indicate an exo stereoconfiguration of the epoxide.     

Azaindoles. V. Pyrido(4,3-b]indoles (γ-carbolines) fonctionnalisés sur leur sommet 4: Synthèse en une seule étape

In boiling diphenylether phenylhydrazine reacts with 1,2-dihydro-2-oxo-4-hydroxypyridines to give 3,4-dihydro-4-oxo(9H)-pyrido[4,3-b]indoles (γ-carbolines) in one step. Nucleophilic displacement of their 4-chloro derivatives by secondary amines affords both 3,4-disubstituted γ-carbolines and chlorination of 2,3-dimethyl-4-oxo(9H)pyrido[4,3-b]indoles, as well as methylation of 2-methyl-4-chloro-(9H)pyrido[4,3-b]indole leads to derivatives in the (3H)4-substituted pyrido[4,3-b] indole series.     

Recherches sur la formation et la transformation des esters LXXVI [1] Sur la réaction de l'isocyanate d'o-méthoxycarbonyl-phényle avec quelques acides amino (ou hydrazino) alcoyl-orthophosphoriques et -sulfuriques

o-Methoxycarbonyl-phenyl isocyanate reacts with mono-aminoalkyl orthophosphoric and sulfuric acids to yield the corresponding 1,2,3,4-tetrahydroquinazoline-2,4-dione-3-ethyl phosphoric (or sulfuric) monoesters which are isolated as sodium salts. 1,2,3,4-Tetrahydroquinazoline-2,4-dione-3-ethyl phosphoric acid has been isolated by adding hydrochloric acid to an aquous solution of its sodium salt.     

Synthesis of 4-Amino-substituted-6-hydroxy and 11-hydroxynaphtho[2,3-g]quinoline-5,12-diones,and the unexpected formation of disubstituted imidazo[4,5,l-i,j]naphtho[2,3-g]quinolin-7-ones

4-Chloroquinoline-5,8-dione ( 8a ) and 6-bromo-4-chloroquinoline-5,8-dione ( 8b ) were reacted with homophthalic anhydride to give tetracyclic compounds 10 and 11 respectively. The 6,11-dihydroxy derivative 12 was prepared in low yield by photochemical addition of benzocyclobutenedione to 4-chloroquinoline-5,8-dione ( 8a ) and in better yield through a Friedel-Crafts reaction of phthalic anhydride with 4-chloro-5,8-dimethoxyquinoline ( 7a ). Whereas 4-chloro-6-hydroxynaphtho[2,3-g]quinoline-5,12-dione ( 11 ) was substituted by amines in the usual way to the corresponding 4-amino-substituted derivatives, 4-chloro-11-hydroxynaph-tho[2,3-g]quinoline-5,12-dione ( 10 ) led to a mixture of 4-amino derivatives and the unexpected 2,6-disubstituted-imidazo[4,5,l-I-j]naphtho[2,3-g]quinolin-7-ones, 13a-b .     

Global optimization and simulated annealing

In this paper we are concerned with global optimization, which can be defined as the problem of finding points on a bounded subset of ⁿ in which some real valued functionf assumes its optimal (maximal or minimal) value.We present a stochastic approach which is based on the simulated annealing algorithm. The approach closely follows the formulation of the simulated annealing algorithm as originally given for discrete optimization problems. The mathematical formulation is extended to continuous optimization problems, and we prove asymptotic convergence to the set of global optima. Furthermore, we discuss an implementation of the algorithm and compare its performance with other well-known algorithms. The performance evaluation is carried out for a standard set of test functions from the literature.     

Hydrothermal synthesis of porous materials from sepiolite

In order not only to manufacture a tough porous material from sepiolite but also to sustain the inherent properties of the sepiolite, a hydrothermal experiment was carried out under saturated steam pressure at 473 K for up to 24 h by mixing slaked lime. The experimental results show that the addition of slaked lime exerts a positive effect on the strength development, and the strength enhancement is found to be due to tobermorite and calcium silicate hydrate (CSH) gel formation. Curing time seems to condition the strength development. A fine particle size of sepiolite improves its activity during the hydrothermal process, thus offering a higher strength and quicker hardening rate of the synthesized specimen. The acid activation also has a beneficial effect on the strength development. The hardening mechanism of the synthesized specimen is different between the specimens synthesized with or without acid activation. The strength enhancement for sepiolite with acid activating is due mainly to CSH gel formation, instead of tobermorite formation without acid activation.