Calcium chloride with one drop of conc. HCl was found facile and efficient catalyst for the synthesis of aryl 14H-dibenzo[a,j] xanthenes via one-pot condensation of  various substituted benzaldehydes and β-naphthol under microwave and solvent-free conditions. The present protocol offers several advantages such as shorter reaction time, good to excellent yields, simple to operate, inexpensive and easily available catalyst.

Riolozatrione is a natural diterpene isolated form Jatropha dioica to which anti-viral activity is attributed. In this work we report the synthesis of 5 new derivatives and its anti-herpetic evaluation. Riolozatrione posses a unique diterpene core attractive for chemical modification. Conjugate ketone was selectively hydrogenated whereas sodium borohydride draws for three different riolozatrione analogues. 

Nanoporous heterogeneous catalysts have been applied in many reactions due to the high contact area and orderly porous structures with thermal, chemical and mechanical stability [1]. Pyrroles and their derivatives are one of the most important classes of heterocyclic compounds [2]. A four-component coupling reaction (4cr) consisted of aldehydes 1, amines 2, 1, 3 -dicarbonyl compounds 3 and nitromethane 4 afforded substituted pyrroles 5, using MCM-41-SO3H as heterogeneous catalyst. We investigated the synthesis of pyrrole derivatives in the solvent-free conditions. Products were obtained in good yields and short times.

4a-Methyl-2,3,3,4a-tetrahydro-1H-carbazole (3), obtained from phenylhydrazinium chloride and 2-methylcyclohexanone, was regioselectively reduced with sodium borohydride to 4a-methyl-2,3,4,4a,9a-hexahydro-1H-carbazole (4).

Cyclocondensation of hexahydrocarbazole 4 with 2 molecules of diethyl malonate 5a gives 7-hydroxy-13a-methyl-9a,10,11,12,13,13a-hexahydro-5H,8H-pyrano[2',3':4,5] pyrido[3,2,1-jk]carbazole-5,8-dione (6), which affords in a 2-step degradation 5-unsubstituted 4-hydroxy-11a-methyl-7a,8,9,10,11,11a-hexahydro-6H-pyrido[3,2,1-jk]carbazol-6-one (9). Nitration of 9 forms the 5-nitro compound 12, which cyclized after chlorination and azidation at position 4 on thermolysis to the 12a-methyl-7-oxo-8a,9,10,11,12,12a-hexahydro-7H-[1,2,5]oxadiazolo[3',4':4,5]pyrido[3,2,1-jk] carbazol-6-oxide 15.

Cyclocondensation of hexahydrocarbazole 4 with phenylmalonate 5b forms 4-hydroxy-11a-methyl-5-phenyl-7a,8,9,10,11,11a-hexahydro-6H-pyrido[3,2,1-jk]carbazol-6-one (16a), which cyclized after chlorination and azidation at position 4 on thermolysis to the 3b-methyl-3b,4,5,6,7,7a-hexahydroindolo[2',3':4,5]pyrido[3,2,1-jk]carbazol-9(14H)-one derivative 19. The conditions in the thermolytical decomposition and cyclization of the azido compounds were investigated by differential thermal analysis (DSC).

Naphthoquinones are natural pigments that widely distributed in nature and have important biological activities. Lawsone (2-hydroxy-1,4-naphthoquinone) and its synthetic derivatives, and especially those containing nitrogen, have promising potential for the treatment of different diseases due to their antibacterial, antifungal, antiviral, antitumor and antiparasitic effects [1].

     The Mannich reaction is one of the most widely used three component reactions which utilizes a non-enolizable aldehyde, a primary or secondary amine and an enolizable carbonyl compound resulting -amino carbonyl compounds [2]. In this work, we used carboxymethyl cellulose (CMC) as heterogeneous catalyst for multicomponent mannich reaction. CMC is a cellulose derivative with carboxymethyl groups, it is widely used, and inexpensive, biodegradable.

     Synthesis of 2-hydroxy-1,4- naphtoquinone derivatives were performed by simple reaction between 2-hydroxy-1,4- naphtoquinone, aromatic aldehydes and amines in the presence of CMC. The advantages of this procedure are excellent yields within short times, green catalyst and mild reaction conditions.