Synthesis, structure and some reactions of 4a',5′,6′,7′,8′,8a'‐hexahydro‐4′<i>H</i>‐spiro[cyclohexane‐1,9′‐[1,2,4]triazolo[5,1‐<i>b</i>]‐quinazolines]

Abstract

Abstract magnified image 2′‐Substituted 5′,6′,7′,8′‐tetrahydro‐4′ H ‐spiro[cyclohexane‐1,9′‐[1,2,4]triazolo[5,1‐ b ]quinazolines] 3a‐d were synthesized by condensation of 3‐substituted 5‐amino‐1,2,4‐triazoles 1a‐d with 2‐cyclohexylidene cyclohexanone 2 in DMF. The compounds 3 were hydrogenated with sodium borohydride in ethanol to give 2′‐substituted cis ‐4a',5′,6′,7′,8′,8a'‐hexahydro‐4′ H ‐spiro[cyclohexane‐1,9′‐[1,2,4]triazolo[5,1‐ b ]quinazolines] 4a‐d in high yields. The reactions of alkylation, acylation and sulfonylation of the compounds 4 were studied. The structure of the synthesized compounds was determined on the basis of NMR measurements including HSQC, HMBC, NOESY techniques and confirmed by the X‐ray analysis of 6 and 11b . The described synthetic protocols provide rapid access to novel and diversely substituted hydrogenated [1,2,4]triazolo[5,1‐ b ]quinazolines.