Are there alternatives to Azathioprine Impurity 9 (CAS: 872-49-1) in synthesis?

While Azathioprine Impurity 9 (CAS: 872-49-1) is a critical component in certain synthesis processes, alternatives such as other sulfur-containing impurities or analogs can be considered. Common alternative reagents include thiourea and other sulfur-containing compounds that can be used as substitutes based on the specific synthesis requirements and compatibility.