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Synthesis of Imidazole Derivatives Using 2‐Unsubstituted 1 H ‐Imidazole 3‐Oxides
Author(s) -
Mlostoń Grzegorz,
Celeda Małgorzata,
Prakash G. K. Surya,
Olah George A.,
Heimgartner Heinz
Publication year - 2000
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/(sici)1522-2675(20000412)83:4<728::aid-hlca728>3.0.co;2-b
Subject(s) - chemistry , imidazole , combinatorial chemistry , medicinal chemistry , organic chemistry
The reaction of 1,4,5‐trisubstituted 1 H ‐imidazole 3‐oxides 1 with Ac 2 O in CH 2 Cl 2 at 0 – 5° leads to the corresponding 1,3‐dihydro‐2 H ‐imidazol‐2‐ones 4 in good yields. In refluxing Ac 2 O, the N ‐oxides 1 are transformed to N ‐acetylated 1,3‐dihydro‐2 H ‐imidazol‐2‐ones 5 . The proposed mechanisms for these reactions are analogous to those for N ‐oxides of 6‐membered heterocycles ( Scheme 2 ). A smooth synthesis of 1 H ‐imidazole‐2‐carbonitriles 2 starting with 1 is achieved by treatment with trimethylsilanecarbonitrile (Me 3 SiCN) in CH 2 Cl 2 at 0 – 5° ( Scheme 3 ).