7-Chloromethyl 17R-Drospirenone

7-Chloromethyl 17R-Drospirenone is a stereospecific synthetic derivative of drospirenone featuring a 7-chloromethyl substitution on the 17α-pregnane scaffold. The 17R configuration at the sulfur-containing thione group distinguishes its spatial orientation relative to the parent hormone. This impurity arises from selective chloromethylation at C-7 during API synthesis, retaining the 13-ethyl, 3-oxo, and 17-thione functionalities critical to drospirenone’s pharmacophore. Its structural similarity to the parent compound enables use as an HPLC reference standard for impurity profiling in quality control workflows.