3-Amino-2-pyrazinecarboxaldehyde

Preparation of 3-aminopyrazine-2-carbaldehyde EPO 3-Aminopyrazine-2-carboxylic acid methyl ester (3.0 g, 20 mmol) was suspended in tetrahydrofuran (100 ml) under a nitrogen atmosphere and cooled to 0 C. Lithium aluminium hydride as a 1.0M solution in tetrahydrofuran (20 ml, 20 mmol) was added dropwise over 30 minutes whereupon the solution was stirred for another 30 minutes. Saturated aqueous ammonium chloride solution (100 ml) was carefully added (evolution of gas) and the resulting mixture acidified (pH 1) with 4M hydrochloric acid, shaken (5 minutes) and then basified again (pH 10) with saturated aqueous sodium hydrogen carbonate solution. The mixture was extracted with diethyl ether (3 x 150 ml) and the combined organic phase dried (MgS04) and concentrated in vacuo. The yellow oily residue was applied to column chromatography (silica gel/dichloromethane/methanol) and the first fraction was concentrated in vacuo to yield the aldehyde as pale yellow crystals (689 mg, 28 percent). 1H-NMR (400 MHz, DMSO-d6): delta 9.90 (1H, s); 8.31 (1H, d); 8.02 (1H, d); 7.67 (2H, bs). APCI-MS m/z: 124 (MH+).Preparation of 3-aminopyrazine-2-carbaldehyde EPO 3-Aminopyrazine-2-carboxylic acid methyl ester (3.0 g, 20 mmol) was suspended in tetrahydrofuran (100 ml) under a nitrogen atmosphere and cooled to 0 C. Lithium aluminium hydride as a 1.0M solution in tetrahydrofuran (20 ml, 20 mmol) was added dropwise over 30 minutes whereupon the solution was stirred for another 30 minutes. Saturated aqueous ammonium chloride solution (100 ml) was carefully added (evolution of gas) and the resulting mixture acidified (pH 1) with 4M hydrochloric acid, shaken (5 minutes) and then basified again (pH 10) with saturated aqueous sodium hydrogen carbonate solution. The mixture was extracted with diethyl ether (3 x 150 ml) and the combined organic phase dried (MgS04) and concentrated in vacuo. The yellow oily residue was applied to column chromatography (silica gel/dichloromethane/methanol) and the first fraction was concentrated in vacuo to yield the aldehyde as pale yellow crystals (689 mg, 28 %). 1H-NMR (400 MHz, DMSO-d6): delta 9.90 (1H, s); 8.31 (1H, d); 8.02 (1H, d); 7.67 (2H, bs). APCI-MS m/z: 124 (MH+).EXAMPLE 76 Preparation of 3-aminopyrazinecarboxaldehyde STR162 A suspension of 3-aminopyrazine methanol, 6.3 g (0.05 mol) and manganese dioxide (38.0 g) in 400 mL of chloroform is stirred at room temperature for two hours and the resulting solid is filtered off. The filtrate is evaporated to dryness which gives the desired product as a yellow crystalline solid, (5.00 g, 82% yield) having a melting point 110-114 C.General procedure: A soln. of aldehyde C-3 (1 eq) and amine BB-9 (1 eq) in TFE (2 mL/mmol) was heated to 40C and stirred for 10 min. NaBH4 (1.2 eq) was added portionwise at RT and the rxn mixture was stirred for a given time at a given temperature (see Table 34). It was filtered and the filtrate was concentrated in vacuo. The crude was purified by CC using Hept/EtOAc.

Molecular Weight:123.11
XLogP3:-0.2
Hydrogen Bond Donor Count:1
Hydrogen Bond Acceptor Count:4
Rotatable Bond Count:1
Exact Mass:123.043261792
Monoisotopic Mass:123.043261792
Topological Polar Surface Area:68.9
Heavy Atom Count:9
Complexity:106
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes