Lamotrigine → HCID 178511371, compound

Participants

Reaction Steps

The synthesis of lamotrigine is illustrated in Reference Example 1. 2,3-Dichlorobenzoyl cyanide, which is intermediate 1.4 in that synthesis, may contain up to 10% of 2,3-dichlorobenzoic anhydride as a contaminant. When the 2,3-dichlorobenzoyl cyanide is treated with a solution of aminoguanidine bicarbonate in sulphuric acid, which is step (d) in Reference Example 1, the adduct (Z)-2-(2,3-dichlorophenyl)-2-(guanidinoimino)acetonitrile (intermediate 1.5) is produced. The anhydride contaminant can then react with the latter adduct to form (Z)-2-(2,3-dichlorophenyl)-2-[N′-(2,3-dichlorobenzoyl)guanidinoimino]acetonitrile, which is the direct precursor to compound B. Cyclisation of the precursor in propan-1-ol under reflux yields compound B.

Provenance & Evidence