Thiazolo triazole

Dimerization of 2-amino-3,4,6-tri-0-benzyl-2-deoxy-D-glucose with l.l -thionyl-or sulfonyl-di-imidazole gave the fructosazine and bis-tetrahydropyrano-piper-azine derivatives 73 and 74 in a ratio of 1 5, respectively a related compound appeared in Vol. 25, p.l32. The P-carboline derivative 75, isolated as a natural product from a hybrid plant cell culture product, was synthesized in six steps from tryptamine and ( )-4,5,6-tri-0-acetyl-2,3-dideoxy-D-ery/Aro-hex-2-enose. Thiazolo-triazoles such as 76, termed acyclo-C-nucleosides, were obtained on deacetylation of the product from condensation of peracetylated D-gluconic or galactaric acids with 4-araino-3-aryl-l,2,4-triazole-5-thiols in the presence of POCls. The related 1,2,4-triazole 77 and dihydroimidazole 78 were obtained by condensation of D-glucono-1,5-lactone with aminoguanidine and ethylenedia-mine, respectively, followed by acetylation then O-deacetylation. ... 

This reaction occurs on the ring nitrogen (101, 314-316), and the resulting 2,3-diaminothiazoliura salt (160) is then used as a starting material to obtain the thiazolo(3.2-b)-s-triazole (161) (Scheme 101) (101, 314). 

The 3-amino group brings a second nucleophilic center in these structures thus 2-imino-3-amino-4-methyl-4-thia201ine (409) reacts with methyl diloroformate to give the bicyclic compound (410) (Scheme 234). Other thiazolo-s-triazoles of the [3.2-l>] type have been obtained by... 

Thiazolo[3,2-/>][l,2,4]triazoles are often sufficiently reactive to be brominated in the thiazole nucleus (see also B,5). Thus, although the unsubstituted substrate and the 2-phenyl and 2-methyl derivatives would not react with NBS in refluxing chloroform, the 5-methyl, 2,5-dimethyl, and 5-methyl-2-phenyl compounds gave 6-bromo products (71JAP71/26498 74JHC459). 

A novel one-step synthesis of thiazolo[3,2-fc]l,2,4-triazoles 182 was reported from the reaction of chalcones 180 with bis(l,2,4-triazolyl)sulfoxide 181 . 1,2,4-... 

SNSI (Dibenzothiazol-2-yl)tetraazathiapentalene 15 < 2004EJ04203> NNSI 6-(4 -methoxyphenyl)thiazolo-[3,2- ][l,2,4]triazol-5-yl (/i-tolyl)methanone 16 <20000L429> (Figure 3), 6-(4-nitrobenzyl)-2-phenylthiazolo[3,2- ]-[l,2,4]triazole 17 <2005TL1607>, 5-benzylidene-2-(2 -cholorophenyl)thiazolo[3,2- ][l,2,4]triazol-5(677)-one 18... 

Bromination of 2-aryl-thiazolo[3,2-A [l,2,4]triazoles 164 gives the corresponding 5-substituted 6-bromo thia-zolo[3,2-/ ][1,2,4]triazoles 165 (Equation 5) <2000FAR71>. 

Condensation of compound 185 with different functionalized aromatic aldehydes yields 6-substituted thiazolo[3,2- ][l,2,4]-triazol-5(6//)-ones 46 (Equation 13) <1998PHA94, 2001IJH313>. 

Dimethoxy-3-methyl-l-(4-nitrophenyl)-iV-(5, 6 -dihydrothiazolo[3,2-b][l,2,4]triazol-2 -yl)isoquinolinmm bromide 45 is also prepared by reacting 4,5-dimethoxy-2-(4-nitrobenzoyl)phenylacetone 219 with 2-amino-5,6-dihydro-thiazolo[3,2- ][ 1,2,4]triazole 42 <2003JHC821, 2003JHC1041> (Equation 23). 

Acylation of thiosemicarbazides with acyl chloride 222, under standard basic conditions, gives 2-aryl-5-methyl-thia-zolo[3.2-// [ l, 2,4]triazolc-6-carbothiosemicarbazides 223, that on sodium hydroxide-promoted cyclization affords 2-aryl-5-methyl-thiazolo[3,2-4][l,2,4]triazol-6-yl)-l//-l,2,4-triazole-3-thiones224 (unreported yields) (Scheme 14) <2001FAR15>. 

Treatment of aroylthiosemicarbazides with a-haloketones provide thiazole derivatives 283, which after POCI3-promoted cyclization give thiazolo[2,3-c][l,2,4]triazoles 93 (Scheme 28) < 1996IJH21, 2002IJC(B)403,... 

Very interestingly, similar l,2-thiazolidin-4-ones 300 behave differently in a basic medium, reacting with sodium hydroxide to give thiazolo[3,4-A][l,2,4]triazoles 134 (Equation 46) <1996JCR(S)388, 2003PS(178)1175>. 

The intramolecular iodine-promoted cyclization of 2-(2-methyl-2-propenylthio)-l,2,4-triazoles 317 exclusively afford the corresponding thiazolo[3,2-3][l,2,4]triazolium perchlorates 318 (Equation 55) <1999RJOC730>. 

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