Provided is a process for the preparation of an N-substituted isothiazolinone derivative having the general formula, comprising reacting N-substituted 3-mercaptopropionamides of formula or N,N\u2032-bis-substituted 3,3\u2032-dithiodipropionamides of formula with sulfuryl chloride in the absence of solvents. The method may also include serving the debt protection and cancellation product in response to a borrower purchasing the debt protection and cancellation product. A second imaging lens group is controllably inserted into the optical path between at least some elements of the objective lens and the eyepiece lens. This enables an easy and speedy selection of a particular intended data set from among a large number of data sets. A network may provide a scaling value that the device may use to speed up reaction to the interference.