The OSM Blog

I have conducted a literature search using SciFinder to see if there is an existing straightforward method for the direct carbonylation of chloropyrazine. Finding such a method would be very useful because 6-chloropyrazine-2-carboxylic acid is a key intermediate in the synthesis of series four amides. It will need to be made in large quantities and in such a way that avoids lengthy experimental procedures and the purchase of expensive compounds.

Methods for the synthesis of 6-chloropyrazine-2-carboxylic acid have already been proposed (see Carbonylation Project - Appeal for a collaborator) and are currently being tested.

 The reaction literature search was conducted as follows:

1) I used the ‘Reaction Structure’ search tool in SciFinder.

2) I drew out the carbonylation reaction I wished to investigate.

I then searched using the search type ‘Allow variability only as specified’. As this did not return any results, I then selected ‘Substructure’ instead.

3) This search method was used for the following carbonylation reactions:

Reaction 1.

Reaction 2.

Reaction 3.

All searches for Reactions 1. and 2. returned either no results or unhelpful ones. However, the ‘exact’ and ‘substructure’ searches of Reaction 3. yielded some patented and literature methods which may be of interest:

In addition, from the answer set result for the ‘exact’ search for Reaction 3., I selected ‘Similar reactions’ and found other experimental procedures of note.

These are summarised here:

Also, I stumbled across another possible reaction pathway in this paper (DOI: 10.1039/C2NJ40791D). The reaction is outlined on p. 400 and is as follows:

This paper, Paladium-catalyzed carbonylation of N-heteroaromatic chloride, may also be of interest.