Abstract: The present invention relates to an IEEE1588 protocol negative testing method, comprises steps of: connecting a IEEE1588 tester and a slave clock DUT to establish a real-time closed-loop feedback mechanism; taking the IEEE1588 tester as a master clock, and establishing a stable time synchronization with the slave clock DUT; obtaining the timing offset or path delay of the slave clock DUT before disturbance; assembling an abnormal message in a frame and sending it to the slave clock DUT; calculating the timing offset or path delay increment after disturbance of the abnormal message; determining whether there is a sudden change in the timing offset or path delay of the slave clock DUT, wherein if there is no sudden change, the test passes; otherwise the test fails.

Abstract: The invention provides two process for synthesizing substituted aminothiazolone compounds as inhibitors of 11-?-hydroxy steroid dehydrogenase type 1. The processes allow the stereoselective synthesis of the desired compounds without the use of stoichiometric amounts of chiral catalysts.