Synthesis of 2,5-dilithio-1-methylimidazole

Efficient Molar-Scale Synthesis of 1-Methyl-5-acylimidazole Triflic Acid Salts

“…1-Methyl-5-formylimidazole is an important synthetic intermediate, − especially in the synthesis of natural products. − Three methods have been previously reported for the preparation of 1-methyl-5-formylimidazole. The first method is the transformation of the 5-formyl group from a corresponding 5-hydroxymethyl, − , or 5-alkoxycarboxyl group. ,, The second method features the installation of the 5-formyl group via a 5-metalated 1-methylimidazole reactive species. ,− The third method entails a regioselective N -methylation of 5-formylimidazole. , In a program of our drug discovery, we required an easy access to a large amount of 1-methyl-5-formylimidazole triflic acid salt…”

Synthesis Routes Towards the Farnesyl Protein Transferase Inhibitor ZARNESTRATM

“…[21] This selectivity at such relatively high temperatures is remarkable in view of suggestions in the literature that the silyl group is unsuitable as a blocking group, owing to the 2-to 5-position migration of 2-(trialkylsilyl)-substituted 5-lithio-N-methylimidazoles. [22,23] Replacement of the hydroxy group by the amino moiety to reach the racemic analogue of 1 was initially achieved in two steps by first treating 20 with thionyl chloride to provide 6-[chloro(4-chlorophenyl)(1-methyl-1H-imidazol-5-yl)methyl]-4-(3-chlorophenyl)-1-methyl-2(1H)-quinolinone (22) and then substituting the chlorine atom in 22 by aqueous ammonia to give 23 (Scheme 5). On a preparative scale this procedure was further improved by performing the chlorination step in N,N-dimethylimidazolidinone and by using ammonia in methanol at a lower temperature.…”

“…Water (64 mL) and aqueous NaOH 50% (7.8 mL) were added to the organic layer which was stirred at room temperature for 1 h. The layers were separated and the organic layer concentrated under reduced pressure to yield 51.08 g (75.6%) of 4-(3-chlorophenyl)-6-[(4-chlorophenyl)hydroxy(1-methyl-1H-imidazol-5-yl)methyl]-1-methyl-2(1H)-quinolinone (20). (22). The product was used without purification in the next step.…”

“…The mixture was stirred at 40°C overnight. The solvent was evaporated to dryness to give 3.49 g of 6-[chloro(4-chlorophenyl)-(1-methyl-1H-imidazol-5-yl)methyl]-4-(3-chlorophenyl)-1-methyl-2(1H)quinolinone monohydrochloride (22). The product was used without purification in the next step.…”

Silylimidazolium Hexafluorophosphate Salts as Synthetic Precursors to N-Heterocyclic Carbene Pentafluorophosphorus Adducts

“…On the other hand, we considered 5-silylimidazolium salts 1 as alternative precursors, reasoning that the imidazol-5-ylidene 5 (an “abnormal NHC” , ) initially generated upon desilylation could equilibrate to the more stable “normal NHC” , in the presence of a catalytic weak Brønsted acid like 1 (Figure b) or 7 (see Figure ). 5-Silylimidazolium salts 1 can be readily synthesized by alkylation or arylation of 5-silylimidazoles, ,, or by lithiation-silylation of imidazol-2-ylidenes − (Figure c).…”