1-Methyl-1H-pyrrole-2-carbaldehyde → 4H,5H-thieno(3,2-c)pyridin-4-one

Participants

Reaction Steps

The synthesis of this compound was accomplished with the same sequence of reactions as used to prepare IIIc, except that the starting material (X) is 3-thiophenecarboxaldehyde. The multiple step preparation of the positional isomer IIIc' was complicated, however, in that the Curtius-type rearrangement reaction (Example 4) gave the desired VI intermediate compound in low yield as the major product of this reaction was a sym-triazine by-product which resulted from trimerization of the isocyanate intermediate. Nonetheless, application of the reactions outlined in Scheme 1 resulted in production of the IIIc' product, which was a brown gum and was used without further purification.

Provenance & Evidence