One-pot synthesis of 1-arylmethylidene-1,2,3,3a-tetrahydro-5H-pyrrolo[1,2-a]-[3,1]benzoxazines and 1-arylmethylidene-1,2,3,3a,4,5-hexahydropyrrolo[1,2-a]-quinazolines from 5-arylalk-4-ynals and o-aminobenzylic alcohol/amine
Аннотация:
Cyclization of 5-arylalk-4-ynals with o-aminobenzylamine or o-aminobenzyl alcohol in DMSO under the sequential action of NH4Br and KOH affords (E)-1-arylmethylidene-1,2,3,3a,4,5-hexahydropyrrolo[1,2-a]quinazolines or (E)-1-arylmethylidene-1,2,3,3a-tetrahydro- 5H-pyrrolo-[1,2-a][3,1]benzoxazines; the latter without substituents in the 3-position easily isomerize into the corresponding 2-arylmethyl- 1-(2-hydroxymethylphenyl)pyrroles.