Trimethyl borate → HCID 145857664, compound

Participants

Reaction Conditions

Reaction Steps

Butyllithium (2.5 M, 1.88 mL, 4.5 mmol) was added dropwise to a −78° C. solution of 3-bromo-4-methylpyridine (645 mg, 3.75 mmol) in Et2O (15 mL). The solution was stirred at −78° C. for 1 h and trimethylborate (5 mL, 44 mmol) was added in one portion. The solution was warmed to rt over 15 min and stirred for 2 h at rt. The volatile components were removed in vacuo and the solid residue was dried under high vacuum for 2 h. A portion of the crude solid (81 mg, 0.4 mmol) was reacted with {[4-(3-bromo-benzenesulfonyl)-5-methylsulfanyl-thiophen-2-yl]-imino-methyl}-carbamic acid tert-butyl ester (Example 27 (50 mg, 0.1 mmol)), Pd(PPh3)4 (29 mg, 0.025 mmol), Na2CO3 (2M, 0.8 mL, 1.6 mmol), ethanol (0.8 mL) and toluene (1.6 mL) according to the procedure used in Example 1: step c. Analogous aqueous workup and purification of the crude material by preparative TLC (50% EtOAc in hexanes) yielded the title compound (36 mg, 71%) as a light-yellow glass. 1H-NMR (CDCl3): δ 8.50 (d 1H, J=5.1 Hz), 8.42 (s, 1H), 8.07 (s, 1H), 7.99 (m, 2H), 7.45–7.70 (m, 5H), 7.24 (d, 1H, J=5.1 Hz), 2.59 (s, 3H), 2.27 (s, 3H), 1.52 (s, 9H). ESI-MS (m/z): Calcd. for C23H25N3O4S3: 503.7; found: 503.8.

Provenance & Evidence