Synthesis of Fused Heterocycles Based on 1-Amino-1H-tetrazole-5-thiol and α,β-Unsaturated Aldehydes

Russian Journal of General Chemistry - 8-Phenyltetrazolo[5,1-b][1,3,4]thiadiazepine was obtained as a result of intermolecular cyclization of 1-amino-1H-tetrazole-5-thiol and 3-phenyl-2-propynal....     

Synthesis of triketones of the phosphonoacetyldiacylmethane series

A new approach to the synthesis of the triketones of triacylmethane series containing a (dimetoxyphosphoryl) acetyl group was developed based on the reaction of β-diketones with dimethyl chloroacetylenephosphonate.     

Highly regioselective heterocyclization reactions of 1H-1,2,4-triazole-3-thiols with chloroacetylenephosphonates

1-Chloroacetylene-2-phosphonates react with 1H-1,2,4-triazole-3-thiols in anhydrous acetonitrile with high regioselectivity to form the fused heterocycles, 6-(dialkoxyphosphoryl)-3H-thiazolo[3,2-b][1,2,4]triazol-7-ylium chlorides 1-5. A significant difference from the previously known reactions of binucleophiles with haloacetylenes is the involvement of both acetylenic carbon atoms in the heterocycle formation. A reaction mechanism is hypothesized that assumes the formation of a sulfenium cation at the acetylene C-1 atom followed by attack of the C-2 atom by the ring N-2 atom. Compounds 1-5 easily lose one alkyl group from the dialkoxyphosphoryl fragment to form zwitterions (e.g., 6-8) which further can be transformed into inner salts 9 and 10 when heated with concentrated hydrochloric acid.     

Synthesis of 2-Propargylaminoethanols from α,β-acetylenic aldimines

A method of synthesis of 2-propargylaminoethanols, perspective synthons for a one-pot synthetic technology excluding isolation of unstable prop-2-ynylideneaminoethanols is developed. A number of 2-propargylaminoethanol hydrochloride derivatives are synthesized, and their ¹H and ¹³C NMR spectra were discussed.     

Synthesis of trivalent phosphorus derivatives by light-induced dibromophosphination of akenes

Light-induced dibromophosphination of alkenes was studied. Dehydrobromination of the synthesized bromoalkylphosphonous dibromides gave the corresponding dibromophosphinoalkenes which were converted into alkenylphosphonous acids and their cyclic esters, benzo[1,3,2]dioxaphospholes.     

Reaction of chloroacetylenephosphonate with acetoacetic ester and its analogs

Russian Journal of General Chemistry -     

Synthesis of 6-chlorotetrazolo[1,5-a]quinazoline and 6-chloro-4,5-dihydrotetrazolo[1,5-a]quinazoline

Russian Journal of General Chemistry - Reaction of 5-aminotetrazole triethylammonium salt and 2-fluoro-6-chlorobenzaldehyde resulted in the formation of 6-chlorotetrazolo[1,5-a]quinazoline instead...