5-Methyl-1H-imidazole-4-carbaldehyde

A mixture of 4-methyl-1 H-imidazole-5-carbaldehyde (5.0 g) and triphenylphosphine (13.0 g) in methanol (150 ml_) is cooled in an ice/water bath and a solution of di-tert- butyl azodicarboxylate (13.0 g) in dichloromethane (100 ml_) is added dropwise and the reaction mixture ist stirred for 2 h at room temperature. More triphenylphosphine (2.6 g) and di-tert-butyl azodicarboxylate (2.4 g) are added and the mixture is stirred for 1 h. The dichloromethane is evaporated from the mixture and CS2CO3 (23.0 g) and dimethyl (1 -diazo-2-oxopropyl)phosphonate (80 %; 13 ml_) are added (exothermal reaction, cooling is recommended) and the mixture is stirred for 3 h at room temperature. Since conversion of starting material is still incomplete, CS2CO3 (51 .0 g) and dimethyl (1 -diazo-2-oxopropyl)phosphonate (80 %; 15 ml_) in methanol (100 ml_) are added in several portions under cooling during the following 24 h until conversion is complete. The mixture is filtered, the filtrate is diluted with methanol and water and acidified with 4 N aqueous HCI. Phases are separated and the aqueous phase is extracted with dichloromethane. The combined organic phases are extracted with water and the combined aqueous phases are basified with 10 N aqueous NaOH and extracted with dichloromethane. The combined organic phases are dried over Na2S04, concentrated in vacuo, and the residue is chromatographed on silica gel ethyl acetate/cyclohexane (4:1 ) to give the title compound. (0178) LC (Method 2): tR = 0.72 min; Mass spectrum (EST): m/z = 121 [M+H]+.

Molecular Weight:110.11
XLogP3:0.3
Hydrogen Bond Donor Count:1
Hydrogen Bond Acceptor Count:2
Rotatable Bond Count:1
Exact Mass:110.048012819
Monoisotopic Mass:110.048012819
Topological Polar Surface Area:45.8
Heavy Atom Count:8
Complexity:94.4
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes