title: Ring expansion reactions of 4-amino-1,1-dioxo-[1,2,3,5]-thiatriazoles.
abstract: An unusual ring-expansion reaction of 4-amino-1,1-dioxo-[1,2,3,5]-thiatriazoles has been identified that produces the relatively rare 5-amino-1,1-dioxo-[1,2,4,6]-thiatriazines and. Initial alkylation of the thiatriazole with alpha-halo-esters at N-3 produces alpha-substituted esters which, under basic reaction conditions, undergo opening of the thiatriazole ring and re-closure to a thiatriazine ring. Similar alkylations of with diethyl chloromalonate and ethyl dichloroacetate lead to the loss of SO2 and the production of triazine and triazole, apparently by an initial alkylation at N-5. The reaction of with phenacyl bromides or a phenacyl dibromide forms fully unsaturated 5-amino-1,1-dioxo-[1,2,4,6]-thiatriazines.
authors.affiliation: CSIRO Molecular and Health Technologies, Bag 10, Clayton South, Victoria 3169, Australia. peter.duggan@csiro.au
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Duggan
authors.forename: Andris J
authors.initials: AJ
authors.lastname: Liepa
authors.forename: Laura K
authors.initials: LK
authors.lastname: O'Dea
authors.forename: C Elisabet
authors.initials: CE
authors.lastname: Tranberg
mesh_terms: D000085:Acetates / Q000737:chemistry; D000478:Alkylation; D003499:Cyclic S-Oxides / Q000737:chemistry*; D003500:Cyclization; D008314:Malonates / Q000737:chemistry; D008956:Models, Chemical; D013237:Stereoisomerism; D013458:Sulfur Dioxide / Q000737:chemistry; D013829:Thiadiazines / Q000737:chemistry; D013830:Thiadiazoles / Q000737:chemistry*; D014227:Triazines / Q000737:chemistry*; D014230:Triazoles / Q000737:chemistry*
chemical_list: D000085:Acetates; D003499:Cyclic S-Oxides; D008314:Malonates; D013829:Thiadiazines; D013830:Thiadiazoles; D014227:Triazines; D014230:Triazoles; D013458:Sulfur Dioxide; C498810:diethyl malonate; C007650:ethyl acetate