Synthesis of 2-Methylsulfanyl-1H-imidazoles as Novel Non-nucleoside Reverse Transcriptase Inhibitors (NNRTIs)

alpha-Aminoketone hydrochlorides 2a-d were synthesized by Dakin-West reaction from L-phenylalanine and L-cyclohexylalanine followed by hydrolysis in acidic medium. Treatment of 2a-d with aqueous potassium thiocyanate afforded 1, 3-imidazole-2-thiones 3a-d which were alkylated with methyl iodide to give 2-methylsulfanyl-1H-imidazoles 4a-d with 4-benzyl/4-cyclohexylmethyl and 5-ethyl/5-isopropyl substituents. Coupling of 4a-d with ethoxymethyl chloride or benzyloxymethyl chloride furnished N-1 5a-d and N-3 6a-h alkylated products. The synthesised compounds were tested for their activity against HIV-1. The most active compounds have a cyclohexylmethyl group in the 5-position of 6 and showed an activity against HIV-1 comparable to the activity of Nevirapine.