Thiazolopyrimidines was written by Childress, Scott J.;McKee, R. L.. And the article was included in Journal of the American Chemical Society in 1951.Computed Properties of C6H3Cl2N3S This article mentions the following:
The synthesis of the thiazolo[5,4-d]pyrimidines of Weidel and Niemilowicz [Monatsh. 16, 721(1895)], and of Fischer and Ach [Ann. 288, 157(1895)] was extended. The previously reported synthesis of these compounds (Erlenmeyer and Furger, C.A. 41, 5133e) is unreliable. 6-Thiouramil (I) in 20 cc. 85% HCO2H refluxed 4 hrs., and the product cooled, filtered, dissolved in 35 cc. hot NH4OH, and precipitated with hot dilute HCl yielded 0.9 g. thiazolo[5,4-d]pyrimidine-5,7-diol (II), did not m. below 360掳. I (1.5 g.) and 15 g. Bz2O heated 3 hrs. on a steam bath and 30 min. at 170掳 and the product diluted with Et2O yielded 2.0 g. 2-Ph derivative of II, m. well above 360掳 (decomposition) (from 50% AcOH). II (0.5 g.) and 5 g. POCl3 heated 12 hrs. at 200掳, and the product cooled and poured over 30 g. ice, filtered, recrystallized from MeOH, and sublimed in vacuo yielded 0.15 g. 5,7-dichlorothiazolo[5,4-d] pyrimidine (III), m. 148.5-9.5掳. The 2-Me derivative (IIIA) of II (3 g.) and 50 g. POCl3 at 170掳 yielded 2.7 g. 2-Me derivative (IV) of III, white crystals, m. 109-10掳. IV (1 g.) and 15 cc. concentrated NH4OH heated 4 hrs. at 155掳, and the product chilled and filtered yielded (from 5 combined runs) 1.2 g. 5,7-diamino analog (V), of IV, white crystals from MeOH, m. 255-7掳. V has been submitted for pharmacol. evaluation. Di-Et 4,5-thiazoledicarboxylate (15 g.) and 40 cc. NH4OH yielded 9 g. 4,5-thiazoledicarboxamide (VI), white crystals from water, m. 298-300掳 (decomposition). Di-Et 2-methyl-4,5-thiazoledicarboxylate (VIA) (8 g.) and 20 cc. concentrated NH4OH yielded 4 g. 2-methyl-4,5-thiazoledicarboxamide (VII), white crystals from 50% EtOH, m. 296掳 (decomposition). Di-Et 2-phenyl-4,5-thiazoledicarboxylate (3 g.) yielded 2.5 g. diamide (VIII), white crystals from AcOH, m. 319-21掳. Br (1.8 g.) in 28 cc. water at 0掳 containing 3.6 g. KOH added to 2 g. VI, the mixture stirred 3 hrs. at 0掳 with addition of HOBr at intervals, the solution refrigerated overnight, filtered, heated 20 min. at 80掳, and the product precipitated with AcOH yielded 1.3 g. thiazolo[4,5-d]pyrimidine-5,7-diol (IX), did not m. below 360掳. IX (1.5 g.) and 30 g. PCl5 heated 12 hrs. at 200掳, the product added to 200 g. ice, and the solid filtered off and sublimed in vacuo yielded 0.2 g. product, m. 155-65掳; the filtrate made alk. with NH3 and the light yellow needles sublimed in vacuo yielded 0.7 g. 6-amino-2,4,5-trichloropyrimidine (X), white crystals, m. 170-1.5掳. X (0.7 g.) and 10 cc. concentrated NH4OH treated overnight at 100掳, chilled, filtered, the solid leached with hot EtOH, and the residue crystallized from EtO yielded a small amount of 4,6-diamino-2,5-dichloropyrimidine, m. 299-300掳; the alc.-soluble portion yielded 0.3 g. 2,4,6-triamino-5-chloropyrimidine, m. 197-9掳 (from water). VII (2 g.) treated with HOBr yielded 1.7 g. 2-methylthiazolo[4,5-d]pyrimidine-5,7-diol (XA), did not m. below 360掳. VIII (1.8 g.) treated with 56 cc. KOBr did not completely dissolve; the yield was 0.5 g. of the 2-Ph analog of XA, light-cream crystals, m. 331-2掳 (from 50% AcOH). VIA (1 g.) and 5 cc. 85% N2H4.H2O kept 1 hr. in 10 cc. EtOH at room temperature yielded the dihydrazide. VIA (7 g.) in 50 cc. EtOH and 5.3 g. 85% N2H4.H2O heated 48 hrs. at 100掳 and 30 min. at 140掳 yielded 2 g. 2-methylthiazolo-[4,5-d]pyridazine-4,7-diol, pale yellow powder from AcOH and from water, darkened slightly above 300掳, m. 355掳 (decomposition). IIIA (0.7 g.) refluxed with 10 g. BzH and 1 g. ZnCl2 yielded 0.3 g. 2-styrylthiazolo[5,4-d]pyrimidine-5,7-diol (XI), did not m. below 360掳; XA (0.7 g.) yielded 0.3 g. [4,5-d] isomer of XI, yellow powder, m. 329-31掳 (decomposition). In the experiment, the researchers used many compounds, for example, 5,7-Dichloro-2-methylthiazolo[5,4-d]pyrimidine (cas: 7464-11-1Computed Properties of C6H3Cl2N3S).
5,7-Dichloro-2-methylthiazolo[5,4-d]pyrimidine (cas: 7464-11-1) belongs to thiazole derivatives. Thiazole rings are planar and aromatic. Thiazoles are characterized by larger pi-electron delocalization than the corresponding oxazoles and have therefore greater aromaticity. Thiazole is a versatile building block for the construction and lead generation of new drug discoveries. Numerous diazole-based compounds are in clinical use as anticancer, antileukemic, antiinflammatory, antiviral, antifungal, antirheumatic, immunomodulator, and antiparasitic agents.Computed Properties of C6H3Cl2N3S
Referemce:
Thiazole | C3H3NS – PubChem,
Thiazole | chemical compound | Britannica