Pyrimidine-5-carboxaldehyde

A modified procedure of Rho and Abuh (Syn. Commun. 1994, 24, 253-256) was followed for the preparation of the titled aldehyde. 1) Step 1. Pyrimidine-5-carbaldehyde 2: To a solution of 5-bromopyrimidine (1Og, 56.96 mmol) in THF (500 mL) under the an inert atmosphere of nitrogen was added butyllithium (20 ml, 3.6 M) dropwise with stirring while cooling to a temperature of -100 C. The resulting solution was allowed to stir for an additional 1 hour at -100 C, followed by adding HCl (5 ml) dropwise with stirring while keeping the temperature at - 80 C and then warmed up to room temperature. The reaction progress was monitored by TLC (EtOAc/PE = 1:1). The resulting solution was extracted with ethyl ether (3 x 500 ml) and the organic layer was combined and dried over Na2SO4 and concentrated by evaporation under vacuum using a rotatory evaportator yield 2 g (29percent) of pyrmidine-5-cabaldehyde as an colorless oil.[0745] Synthesis of pyrimidine-5-carbaldehyde: [0746] To a stirred solution of 5-bromopyrimidine (5 g, 31.66 mmol) in THF (50 mL) under argon atmosphere was added n-butyl lithium (2.2 g, 34.83 mmol) drop wise for 10 min at -78 °C and stirred for 20 min. To this was added DMF (2.3 g, 31.66 mmol) at -78 °C and stirred for 30 min. The reaction was monitored by TLC; after completion of the reaction, the reaction mixture was quenched with saturated ammonium chloride solution (40 mL) and extracted with EtOAc (3 x 40 mL). The combined organic extracts were washed with water (30 mL), brine (30 mL), dried over sodium sulfate, filtered and concentrated in vacuo to obtain the crude. The crude was purified through silica gel column chromatography using 25percent EtOAc/ Hexanes to afford pyrimidine-5-carbaldehyde (200 mg, 3percent) as colorless thick syrup. TLC: 30percent EtOAc/ Hexanes (R 0.2).In the reaction bottle, Add solvent DMF (560 mL), Cool down to 5 ° C, Slowly add phosphorus oxychloride (230g), Control the reaction temperature of the mixed system to not exceed 5 ° C, After the addition of phosphorus oxychloride, Add aluminum trichloride (133g), Stir for 30min, Then, 112 g (1 mol) of uracil in a solid form was added in portions to the above mixed system.Control the reaction temperature not to exceed 5 ° C, After stirring for 2 hours, Slowly warm to room temperature and continue to stir the reaction until the raw materials disappear.After the reaction is over, Adding the reactants to the rapidly stirred ice-water mixture, Precipitating pyrimidine-5-formaldehyde solid 133g, Yield 95percent, The purity is 99.5percent.1)

Molecular Weight:108.10
XLogP3:-0.3
Hydrogen Bond Acceptor Count:3
Rotatable Bond Count:1
Exact Mass:108.032362755
Monoisotopic Mass:108.032362755
Topological Polar Surface Area:42.8
Heavy Atom Count:8
Complexity:78.5
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes