No abstract

A facile synthetic approach to 3'-substituted-5-cyclopropanespirohydantoins has been developed and used to synthesize some new spirohydantoins. The key aspect is the preparation of -carboethoxy isocyanate basing on Curtius rearrangement, which can be ring-closed to the expected spirohydantoins after the reaction with various amines and hydrazines. Interestingly the cyclopropane ring doesn't open during the whole process.

Hydantoin derivatives R 0210Synthesis and Potential Anticonvulsant Activity of New N-3-Substituted 5,5-Cyclopropanespirohydantoins. -Steps 2 and 3 in the one-pot reaction to α-carboethoxy ureas (IV) include a Curtius rearrangement. The in situ generated isocyanates are then trapped by amines (III). Following ring closure leads to the desired cyclopropanespirohydantoins of type (V) which are tested for their anticonvulsant activity in relation to phenytoin as reference drug. Several compounds, e.g. all derivatives (V), exhibit promising activity. -(ZHU, Q.; PAN, Y.; XU, Z.; LI, R.; QIU, G.; XU, W.; KE, X.; WU, L.; HU*, X.; Eur.