Synthesis and reactions of 2‐(p‐chloroanilino)‐5‐ (D‐galacto‐1,2,3,4,5‐pentahydroxypentyl)‐1,3,4‐thiadiazole

Abstract

Oxidative cyclization of D‐galactose (p‐chlorophenyl)thiosemicarbazone gave 2‐(p‐chloroanilino)‐5‐(D‐galacto‐1,2,3,4,5‐pentahydroxypentyl)‐1,3,4‐thiadiazole (1), whose acetylation afforded 2‐[N‐acetyl‐N‐(p‐chlorophenyl)]‐amino‐5‐(D‐galacto‐1,2,3,4,5‐pentacetoxypentyl)‐ 1,3,4‐thiadiazole (3). Its periodate oxidation of the glycol groups gave 2‐(p‐chloroanilino)‐1,3,4‐thiadiazole‐5‐carboxaldehyde (4), which can be transformed into 1,2‐[2‐(p‐chloroanilino)‐1,3,4‐thiadiazol‐5‐yl]‐1‐hydroxy‐2‐oxoethane. A number of hydrazones of the formyl thiadiazole was prepared and its reduction with sodium borohydride gave 2‐(p‐chloroanilino)‐5‐hydroxymethyl‐1,3,4‐thiadiazole (6), whose acetylation gave a mono‐O‐acetyl derivative (7). Oxidation of the formyl thiadiazole gave 2‐(p‐chloroanilino)‐1,3,4‐thiadiazole (9). The spectral data of the compounds were discussed.

1,3,4-Thiadiazole-2-carboxylate esters: new synthetic methodology for the preparation of an elusive family of self-organizing materials

“…Decarboxylation has been observed previously in 5-amino-1,3,4-thiadiazole-2-carboxylic acids. [30][31][32][33] We therefore decided to isolate the sodium salt of the carboxylic acid (13, a stable molecule unless heated in solution upon which decarboxylation was observed). Direct conversion of 13 into the corresponding acid chloride derivative followed by in situ esterification with the desired alcohols was expected to afford the desired ester adducts.…”

4′, x-Seco And 4′,x-4′,5′-Diseco C-Nucleosides From 2-Hydrazino-(3H)- Thieno [2,3-D] Pyrimidin-4-Ones

“…The mix ture was heated under reflux for 4 h. The product that separated out on cooling was filtered and recrystalized from ethanol to give colorless crys tals (0. 16 (19)(20)(21)(22) A solution of the respective sugar (10 mmol) in water (5 ml) was treated with a solution of 1 or 2 (10 mmol) in ethanol (150 ml) and a few drops of acetic acid. The mixture was boiled under reflux for 2 h. The product that separated out on cooling was filtered, washed with water followed by etha nol and dried.…”

“…The biological im portance of acyclonucleosides [1][2][3] and C-nucleosides [4][5][6][7][8][9][10][11][12][13][14] attracted our at tention towards the synthesis of acyclo C-nucleoside analogues [15][16][17][18][19][20][21][22][23][24][25] of potential chem othera peutic interest. The acyclonucleosides have been recently classified [1][2][3] according to the type of the glycon rather than the aglycon part.…”

Selective cyclisation of 2, 3, 4, 5‐tetra‐O‐acetyl‐galactaric acid bis‐[Alkylthio(thiocarbonyl)]hydrazide to Saccharide 1, 3, 4‐Oxadiazole, Thiadiazole, and thiadiazoline derivatives

“…Saccharide-hydrazides have great importance, especially as a source of saccharide-I ,3,4-oxadiazole [ 1-31, 1,3,4-thiadiazole [4], and 1,3,4-oxadiazoline derivatives [5,6]. These heterocyclic compounds are of biological and industrial use.…”