2931.59.00.20 - O-Isopropyl methylphosphonochloridate

This HTS classification, 2931.59.00.20, specifically designates O-Isopropyl methylphosphonochloridate. This compound is characterized by the presence of a methylphosphonyl group esterified with an isopropyl alcohol moiety, and further featuring a chlorine atom directly bonded to the phosphorus. Its inclusion within the broader category of "Other organo-phosphorous derivatives" highlights its unique structural configuration that does not align with more specific phosphonofluoridate or difluoride subheadings.

It is crucial to distinguish O-Isopropyl methylphosphonochloridate from its sibling entries. For instance, while sibling 2931.59.00.10 also involves O-alkyl methylphosphonofluoridates, the key difference lies in the presence of fluorine instead of chlorine as the halogen atom attached to the phosphorus. Similarly, 2931.59.00.15 covers alkyl phosphonyl difluorides, which have two fluorine atoms and lack the isopropyl ester linkage. The classification of 2931.59.00.20 is precise due to the specific combination of an isopropyl ester and a chloridate functional group.

As this is a leaf node within the HTS, there are no further subcategories for this specific code. Classification at this level is definitive for O-Isopropyl methylphosphonochloridate, and goods imported or exported under this designation will be subject to the tariff rates and regulations associated with this precise chemical entity. Understanding the specific chemical structure, particularly the identity of the ester group (isopropyl) and the halogen (chlorine), is paramount for accurate classification.