1532-97-4

Pale Yellow Solid

Shows selective inhibition of cAMP-dependent protein kinase

2-Alkynyl benzyl azides could smoothly undergo an electrocyclic reaction catalyzed by palladium to afford either 4-bromoisoquinoline or 4-bromoisquinolones selectively under different conditions. 4-Bromoisoquinoline was synthesised in the presence of PdBr2/CuBr2/LiBr in MeCN, and 4-bromoisoquinolone was selectively produced with PdBr2/CuBr2/HOAc in CH2ClCH2Cl[1].

Journal of Heterocyclic Chemistry, 10, p. 409, 1973 DOI: 10.1002/jhet.5570100326

Synthesis of Intermediate-12: 3-Bromoisoquinoline: To a stirred solution of isoquinoline (24 g, 186 mmol) in acetic acid (50 mL) was slowly added N-bromosuccinimide (NBS, 36.2 g, 204.6 mmol) at room temperature. The reaction mixture was heated to 100 °C and the reaction was stirred at this temperature overnight. Upon completion of the reaction, the mixture was cooled to room temperature and subsequently concentrated under reduced pressure to remove the solvent. The resulting crude product was purified by fast column chromatography (eluent: 5% ethyl acetate/hexane) to give 4-bromoisoquinoline (9.2 g, 23.8% yield) as an oil.

[1] Hong-ping Zhang, Hongzhan Xiao, Hong‐Yan Li. “A Selective Synthesis of 4-Bromoisoquinoline and 4-Bromoisquinolone.” Journal of Chemical Research-s (2013).