Methanol → Methyl 2-(4-methyl-6-oxo-2-phenyl-1,6-dihydropyrimidin-5-yl)pentanoate

Reaction equation

[CH3:1][C:2]1[N:3]=[C:4]([C:16]2[CH:21]=[CH:20][CH:19]=[CH:18][CH:17]=2)[NH:5][C:6](=[O:15])[C:7]=1[CH:8]([CH2:12][CH2:13][CH3:14])[C:9]([OH:11])=[O:10].S(Cl)(Cl)=O.[CH3:26]O>>[CH3:1][C:2]1[N:3]=[C:4]([C:16]2[CH:17]=[CH:18][CH:19]=[CH:20][CH:21]=2)[NH:5][C:6](=[O:15])[C:7]=1[CH:8]([CH2:12][CH2:13][CH3:14])[C:9]([O:11][CH3:26])=[O:10]

Participants

Reactant 3

HCID 887Methanol

HCID 24386Thionyl Chloride

HCID 1363461702-(4-Methyl-6-oxo-2-phenyl-1,6-dihydropyrimidin-5-yl)pentanoic acid

Product 1

HCID 136346147Methyl 2-(4-methyl-6-oxo-2-phenyl-1,6-dihydropyrimidin-5-yl)pentanoate

Procedure

The 2-(4-methyl-6-oxo-2-phenyl-1,6-dihydropyrimidin-5-yl)pentanoic acid (17.16 g) was suspended in dry methanol (150 mL) and thionyl chloride (87 mL; 120 mmol) was added dropwise. The stirred reaction mixture was heated at reflux for 18 h. After cooling, the white precipitate was filtered off, washed with methanol and the filtrate was concentrated under reduced pressure. The residue was suspended in ethyl acetate (25 mL) and heptane (50 mL) was added. The white precipitate was filtered and dried under reduced pressure. The filtrate was concentrated and the residue was precipitate another time with the same procedure to furnish 12.1 g (80% overall yield) of the title compound as a white powder. ESI/APCI(+): 301 (M+H); ESI/APCI(−): 299 (M−H).