Syntheses of Potential Degradation Products of Phenylephrine in OTC Products

Compound 1 and 2 are potential major degradants in over the counter (OTC) products containing phenylephrine HCl and dexbrompheniramine maleate or chlorpheniramine maleate. Compound 2 matches the unknown peak in the solution of stressed active and excipient and thus was identified as the correct degradation product. Whether the degradation product is racemic or chiral is not known. This article describes synthesis of both compounds. Compound 2 will be useful as an analytical standard for quantitative analysis of the major degradant in OTC products of phenylephrine HCl and dexbrompheniramine maleate or chlorpheniramine maleate.