Synthesis of some 4-alkoxy- and 6-alkoxy-2-benzo-thiazolylamides was written by Mndzhoyan, A. L.;Azaryan, A. S.;Iradyan, M. A.;Aroyan, A. A.. And the article was included in Azerbaidzhanskii Khimicheskii Zhurnal in 1967.Application In Synthesis of 6-Isopropoxybenzo[d]thiazol-2-amine The following contents are mentioned in the article:
o- and p-Alkoxynitrobenzenes are hydrogenated over Ni-Cr2O3 to give o- and p-alkoxyanilines (I). Treating I with KSCN and Br gave the corresponding II and III, resp., which were converted into the corresponding amides (IV) and (V), resp. Thus, a mixture of 0.3 mole alkoxynitrobenzene, 50 cc. EtOH, and 4 g. Ni-Cr2O3 catalyst was hydrogenated in an autoclave at 110-20°/100 atm. for 10-12 hrs., filtered, and distilled to give 74.8-86.3% I. From I the following II and III were prepared (R, m.p., m.p. hydrochloride, and % yield given): 6-Et, 159-60°, 199-200°, 60.9; 4-Et, 76-8°, 176-8°, 51.9; 6-Pr, 127-9°, 189-90°, 86.5; 6-iso-Pr, 158-9°, 191-3°, 80.2; 4-Pr, 114-15°, 160-1°, 51.2; 6-Bu, 119-21°, 140-1°, 89.6; 6-iso-Bu, 160-1°, 189-91°, 69.1. A mixture of 0.05 mole acyl chloride and 150 cc. 1:1 Me2CO-dioxane placed in a flask connected with extractor in which a paper extraction shell containing 0.1 mole II or III was placed, was heated on a water bath to complete solution of II or III, filtered, washed with Me2CO, and crystallized from EtOH to obtain the following IV (R, R1, m.p., and % yield given): Et, iso-PrCO, 91-2°, 45.5; Et, Bz, 109-10°, 80.5; Et, MeOC6H4CO (A), 120-2°, 85.3; Et, EtOC6H4CO (B), 116-18°, 76; Et, PrOC6H4CO (C), 94-7°, 84.1; Et, iso-PrOC6H4CO (D), 94-6°, 84.2; Et, BuOC6H4CO (E), 97-8°, 81; Et, PhSO2 (F), 155-7°, 87.4; Et, 2-furoyl (G), 129-30°, 83.3; Et, 2-benzofuroyl (H), 152-4°, 71.8; Et, 2-(2,3-dihydrobenzofuroyl) (I), 110-12°, 70.6; Pr, EtC6H4CO, 191-2°, 79; Pr, G, 224-5°, 80.9; Pr, I, 169-70°, 79.1; and the following V (same data): Et, PrCO, 172-3°, 53.3; Et, iso-PrCO, 140-1°, 45.4; Et, Bz, 222-5°, 87.2; Et, A, 198-200°, 86.9; Et, B, 212-13°, 70.1; Et, C, 224-6°, 84.7; Et, D, 197-200°, 73; Et, F, 199-202°, 60.1; Et, E, 202-3°, 68; Et, iso-BuOC6H4CO, 221-2°, 60; Et, G, 158-9°, 51.9; Et, H, 216-17°, 64.6; Et, I, 142-3°, 90.5; Pr, Bz, 220-2°, 69.2; Pr, A, 145-6°, 80; Pr, B, 204-6°, 86.8; Pr, C, 192-4°, 81.1; Pr, D, 189-90°, 91.8; Pr, E, 197-8°, 67.9; Pr, F, 200-2°, 85.4; Pr, G, 151-2°, 79.5; Pr, H, 212-13°, 65.3; Pr, I, 120-1°, 73.4; iso-Pr, iso-PrCO, 136-9°, 40.3; iso-Pr, BuCO, 138-40°, 49; iso-Pr, Bz, 225-6°, 83.7; iso-Pr, A, 228-9°, 73.1; iso-Pr, B, 215-16°, 60; iso-Pr, F, 255-6°, 68.8; iso-Pr, G, 181-4°, 58.6; Bu, BuCO, 140-1°, 70.6; Bu, Bz, 184-6°, 84.6; Bu, A, 181-2°, 50.1; Bu, B, 182-4°, 81.1; Bu, E, 195-7°, 69.8; Bu, H, 158-60°, 76.5; iso-Bu, A, 222-3°, 85.1; Et, ClCH2CO, 170-1°, 81.4; Bu, ClCH2CO, 172-3°, 70.4. A mixture of 0.03 mole Et2NH, 25 cc. EtOH, 0.01 mole (N-6-alkoxy-2-benzothiazolyl)-2-chloroacetamide, and 25 cc. EtOH was heated on a water bath 2-3 hrs., EtOH was distilled, the residue alkalized with 10% NaHCO3 and extracted with Et2O, the extract dried with Na2SO4 and distilled to give the corresponding V: (R, R1, b.p./mm., m.p., and % yield given): Et, Et2NCH2CO, 218-20°/5, 90-2°, 31.9; Bu, Et2NCH2CO, 130-3°/5, 121-2°, 48.3. This study involved multiple reactions and reactants, such as 6-Isopropoxybenzo[d]thiazol-2-amine (cas: 15850-81-4Application In Synthesis of 6-Isopropoxybenzo[d]thiazol-2-amine).
6-Isopropoxybenzo[d]thiazol-2-amine (cas: 15850-81-4) 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. The nitrogen in thiazole is sp2 hybridized and the lone pair of electrons localized on the nitrogen is less reactive due to increased aromatic character and decreased basicity. It is protonated and alkylated/acylated at nitrogen forming hydrochloride and quaternary thiazolium salt.Application In Synthesis of 6-Isopropoxybenzo[d]thiazol-2-amine
Referemce:
Thiazole | C3H3NS – PubChem,
Thiazole | chemical compound | Britannica