Derivatives of 1,3,5-oxadiazine are of considerable interest for pharmacy, medicine and agriculture due to their wide spectrum of biological activity. These heterocyclic compounds exhibit antimicrobial, anti-inflammatory, antitumor and insecticidal properties, which makes them promising structures for the creation of new medicinal and agrochemical preparations. This work presents a step-by-step synthesis of a new derivative of 1,3,5-oxadiazine. In the first step, by reacting N-(1-amino-2,2,2-trichloroethyl)acetamide with 2-bromobenzoyl isothiocyanate, a previously undescribed thiourea, N-((1-acetamido-2,2,2-trichloroethyl)carbamothioyl)-2-bromobenzamide, was obtained. In the next step, this compound was treated with dicyclohexylcarbodiimide (DCC), resulting in cyclization and the formation of a new derivative of 1,3,5-oxadiazine - N-(1-(((2E,4E)-6-(2-bromophenyl)-3-cyclohexyl-2-(cyclohexylimino)-2,3-dihydro-4H-1,3,5-oxadiazin-4-ylidene)amino)-2,2,2-trichloroethyl)acetamide. The reaction was carried out in acetonitrile at reflux for one hour. Presumably, in the first step of the transformation, under the action of DCC, the elimination of a hydrogen sulfide molecule occurs with the formation of an intermediate carbodiimide derivative - N-(((1-acetamido-2,2,2-trichloroethyl)imino)methylene)-2-bromobenzamide. This intermediate then undergoes a [4+2] cycloaddition reaction with another DCC molecule to form the desired 1,3,5-oxadiazine product in 82% yield. Its structure was confirmed by NMR spectroscopy (¹H and ¹³C).