2-Bromo-4-chlorobenzothiazole

General procedure: To a stirred suspension of CuBr (1.57 g, 10.9 mmol) in MeCN (25 ml) was added Copper (II) bromide (134 mg, 0.600 mmol) and 4-chlorobenzo[d]thiazol-2-amine(100mg, 0.542 mmol) were solvated in acetonitrile (1 mL) and THF (1 mL). t-Butylnitrite (0.086 mL, 0.650 mmol) was then added at room temperature. After 30 mm, the reaction mixture was dilute with EtOAc and washed with 1.0 M HC1 followed by brine. The crude material was concentrated and purified by ISCO flash chromatography (0-5percent EtOAc/Hex over 20 mm, 24 g silica gel cartridge, product at 2.5percent.) to affordIntermediate 260A (88 mg, 0.279 mmol, 65.4 percent yield). LC-MS. Method H, RT = 1.20mm, MS (ESI) m/z: 248.0. 250.0, 252.1 (M+H). ‘H NIVIR (4001V11{z, CHLOROFORMd) 7.72 (d, J7.9 Hz, 1H), 7.52 (d, J7.9 Hz, 1H), 7.41-7.33 (m, 1H).General procedure: The quinoxalines in the accompanying table were prepared according to thefollowing general procedure, which is analogous to the procedure described for Example263. Thus, the appropriately substituted 2-bromobenzothiazole (1.0 equiv), PdC12(dppf)-CH2C12 adduct (0.08 equiv), and Intermediate 1-9 (1.1 equiv) were solvated in a 3:1mixture of toluene and ethanol (0.05 M). A 2.0 M solution of aqueous sodium carbonate (9 equiv) was then added, and the mixture was degassed by bubbling argon through the solution for 10 mm. The vial was then sealed under an atmosphere of argon and heated to 105 C thermally for 1 h. The resulting crude solution was diluted with EtOAc, filtered over Celite, concentrated, and purified by preparative HPLC (Method D, unless otherwise indicated) to yield the desired example.Intermediate 1-2 (15.1 mg, 0.048 mmol), PdC12(dppf)-CH2C12 adduct (2.63 mg, 3.22 tmol) and Intermediate 260A (10 mg, 0.040 mmol) were solvated in DMF (1 mL). Sodium Carbonate (2.0 M in H20) (100 tL, 0.200 mmol) was added, and the solutionwas degassed with argon for 10 mm. The vial was then sealed and heated to 100 C in the microwave for 30 mm. The crude solution was filtered and purified by preparativeHPLC (Method D, 45-85% over 10 minutes) to yield Example 260 (4.6 mg, 0.0 12 mmol, 30.5% yield). LC-MS. Method H, RT = 1.44 mm, MS (ESI) m/z: 356.0, 358.0 (M+H). 'HNMR(SOOMHz, DMSO-d6) 9.12 (s, 1H), 8.88 (s, 1H), 8.19 (d, J=7.7Hz, 1H), 8.11 (s, 1H), 7.67 (d, J=7.7 Hz, 1H), 7.48 (t, J=7.7 Hz, 1H), 4.83 (s, 2H), 3.47 (s, 3H), 2.72 (s, 3H).Well dried and substituted with Ar100 mLA Schlenk flask was charged with the compound prepared in step (a) 4-chloro-2-methylbenzo [d] thiazole(551 mg, 3 mmol), Pd2 (dba) 3 (165 mg, 0.18 mmol), DPPF (200 mg, 0.36 mmol), sodium tert-butoxide (432 mg, 4.5 mmol), anhydrous 1, 4-dioxane (15 mL)2, 6-dimethylaniline (406 [mu] L, 3.3 mmol) was added and the mixture was stirred for 18 hoursreflux.After a certain period of time, the reaction mixture was cooled to room temperature and the reaction was terminated by adding an aqueous sat'd NH4Cl solution (15 mL).The organic layer was separated, passed through a silica gel pad, and concentrated. Crude product was recrystallized under ethanol to obtain Compound 1-4. Yield 668 mg (83%).

Molecular Weight:248.53
XLogP3:4
Hydrogen Bond Acceptor Count:2
Exact Mass:246.88581
Monoisotopic Mass:246.88581
Topological Polar Surface Area:41.1
Heavy Atom Count:11
Complexity:157
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes