Isoquinoline-4-carbaldehyde

Off-white to yellow or brown solid

To a solution of 4-bromoisoquinoline 24a (2.0 g, 9.6 mmol) in 30 mL re-distilled THF was added n-butyl lithium (4.0 mL, 10 mmol, 2.5 M in THF) dropwisely at -65° C. under NM-Butyllithium (1.6 M in hexanes, 11.0ml, 17. 6mmol) is added dropwise to a stirred solution of 4-bromoisoquinoline (3.02g, 14. 5mmol) and anhydrous tetrahydrofuran (100ml) at-78°C under nitrogen. The reaction is stirred for 45 min at-78°C and then dimethylformamide (6. 0ml, 77. 5mmol) is added. The reaction is then stirred for 3 h at- 78°C before it is quenched with water. The reaction is then poured into saturated sodium bicarbonate solution (200ml) and extracted with ethyl acetate (100ml x3). The ethyl acetate is washed with brine and dried over sodium sulfate. The sodium sulfate is filtered and the crude product is concentrated on a rotary evaporator. The crude product is purified by flash chromatography on silica gel eluting with 50percent ethyl acetate/hexanes to yield (0.74g, 33percent) of isoquinoline-4-carboxaldeliyde : mass spectrum (ion spray): m/z = 158. 1 (M+1).General procedure: Hippuric acid (10 g, 56 mmol), aromatic aldehydes (43 mmol), potassium acetate (4.22 g, 44 mmol) and acetic anhydride (14 mL, 17 mmol) were added to a 100 mL three-necked flask and heated atreflux for 0.5 h. The reaction mixture was treated with ethanol(20 mL) when the temperature was cooled down to 40 C. Theproduct was further found by precipitation as the temperaturewent down to ambient. The resulting solid was collected, washedwith ethanol (2 10 mL) and then dried to obtain 2ae2r as yellow crystals.

Molecular Weight:157.17
XLogP3:1.6
Hydrogen Bond Acceptor Count:2
Rotatable Bond Count:1
Exact Mass:157.052763847
Monoisotopic Mass:157.052763847
Topological Polar Surface Area:30
Heavy Atom Count:12
Complexity:169
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes