US Patent 6906072 Piperazine compound and pharmaceutical composition containing the compound

The present invention provides a novel compound having a superior calcium antagonism, in particular, a neuron-selective calcium antagonism. Namely, it provides a compound represented by the following formula, a salt thereof or a hydrate of them.In the formula, Ar indicates an optionally substituted 5- to 14-membered aromatic ring etc.; the ring A indicates any one ring selected from a piperazine, a homopiperazine, a piperidine and the like; the ring B indicates an optionally substituted C3-14 on hydrocarbon ring etc.; E indicates a single bond, a group represented by the formula —CO—, etc.; X indicates a single bond, an oxygen atom etc.; R1 indicates a hydrogen atom, a halogen atom, a hydroxyl group etc.; and D1, D2, W1 and W2 are the same as or different from each other and each represents a single bond or an optionally substituted C1-6 alkylene chain.