2,3-Dichloro-5,6-dicyano-1,4-benzoquinone → 2-Aminobenzo[b]thiophene-3-carboxamide
Reaction equation
[NH2:1][C:2]1[S:6][C:5]2[CH2:7][CH2:8][CH2:9][CH2:10][C:4]=2[C:3]=1[C:11]([NH2:13])=[O:12].C(C1C(=O)C(Cl)=C(Cl)C(=O)C=1C#N)#N>C1(C)C=CC=CC=1>[NH2:1][C:2]1[S:6][C:5]2[CH:7]=[CH:8][CH:9]=[CH:10][C:4]=2[C:3]=1[C:11]([NH2:13])=[O:12]Participants
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Conditions
- Temperature
- 40 °C
Procedure
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)).
Workup
- additionThe reaction is mixed for a few hours
- customThe solvent is then removed under reduced pressure
- filtrationthe residue is filtered
- customoptionally purified by column chromatography (e.g.
- washon a silica gel with elution
- additionby a 8:2 mixture of dichloromethane and ethylacetate)
Sources & evidence
- ORD record
- ord-9112636cc59b4070b3943b1faf7a3b51
- Source dataset
- uspto-grants-2012_05
- Patent number
- US08168639B2
Reaction notes
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