2,3-Dichloro-5,6-dicyano-1,4-benzoquinone → 2-Aminobenzo[b]thiophene-3-carboxamide

Participants

Reaction Conditions

Reaction Steps

To obtain a final product with a 3H-pyrimido[4,5-b]benzo[d]thiophen-4-one heterotricyclic core moiety, the 2-amino-4,5,6,7-tetrahydrobenzo[b]thiophene-3-carboxamide (or derivative thereof) intermediate is mixed with an oxidizing agent such as of 2,3-dicyano-5,6-dichloro-parabenzoquinone (DDQ) in a non-polar solvent such as toluene at room temperature. The reaction is mixed for a few hours at moderate heat (e.g. 40° C.). The solvent is then removed under reduced pressure, and the residue is filtered and then optionally purified by column chromatography (e.g., on a silica gel with elution by a 8:2 mixture of dichloromethane and ethylacetate) to yield 2-aminobenzo[b]thiophene-3-carboxamide (or derivative thereof). This intermediate is then reacted according to the general procedure described above, in place of the 2-amino-4,5,6,7-tetrahydrobenzo[b]thiophene-3-carboxamide intermediate (see Scheme 3(b)).

Provenance & Evidence