Phosgene → 4-Methylbenzimidazolone

Participants

Reaction Steps

The 5-amino-5,6-dihydro-4H-imidazo(4,5,1-ij)quinolin-2-ones of the invention may also be prepared by the route shown in Scheme 6. 3-Methyl-1,2-benzenediamine is reacted with carbonyl diimidazole or phosgene to give 4-methylbenzimidazolone (XXXVI). This is refluxed with phosphorus oxychloride to give XXXVII which is protected and reacted with N-bromosuccinimine to give compound XXXIX. This is coupled with VIIb and the resulting adduct LX is hydrolyzed to LI. Reduction with lithium aluminum hydride alcohol LXII which was treated with carbon tetrabromide/triphenylphosphine to give compound 51. Compound 51 was refluxed in acetic acid to effect conversion to compound 6.

Provenance & Evidence