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°. I (1.5 g.) and 15 g. Bz2O heated 3 hrs. on a steam bath and 30 min. at 170° and the product diluted with Et2O yielded 2.0 g. 2-Ph derivative of II, m. well above 360° (decomposition) (from 50% AcOH). II (0.5 g.) and 5 g. POCl3 heated 12 hrs. at 200°, 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°. The 2-Me derivative (IIIA) of II (3 g.) and 50 g. POCl3 at 170° yielded 2.7 g. 2-Me derivative (IV) of III, white crystals, m. 109-10°. IV (1 g.) and 15 cc. concentrated NH4OH heated 4 hrs. at 155°, 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°. 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° (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° (decomposition). Di-Et 2-phenyl-4,5-thiazoledicarboxylate (3 g.) yielded 2.5 g. diamide (VIII), white crystals from AcOH, m. 319-21°. Br (1.8 g.) in 28 cc. water at 0° containing 3.6 g. KOH added to 2 g. VI, the mixture stirred 3 hrs. at 0° with addition of HOBr at intervals, the solution refrigerated overnight, filtered, heated 20 min. at 80°, and the product precipitated with AcOH yielded 1.3 g. thiazolo[4,5-d]pyrimidine-5,7-diol (IX), did not m. below 360°. IX (1.5 g.) and 30 g. PCl5 heated 12 hrs. at 200°, the product added to 200 g. ice, and the solid filtered off and sublimed in vacuo yielded 0.2 g. product, m. 155-65°; 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°. X (0.7 g.) and 10 cc. concentrated NH4OH treated overnight at 100°, 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°; the alc.-soluble portion yielded 0.3 g. 2,4,6-triamino-5-chloropyrimidine, m. 197-9° (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°. 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° (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° and 30 min. at 140° yielded 2 g. 2-methylthiazolo-[4,5-d]pyridazine-4,7-diol, pale yellow powder from AcOH and from water, darkened slightly above 300°, m. 355° (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°; XA (0.7 g.) yielded 0.3 g. [4,5-d] isomer of XI, yellow powder, m. 329-31° (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