3,4‐Dihydroquinazoline derivatives have been known to be the novel and potent T‐type calcium channel blockers. From a systematic variation of 3,4‐dihydroquinazoline derivative 5c (KYS05043), plausible SAR results were established. It was revealed that a 5‐(dimethylamino)pentylamino group at R1, a biphenyl group at R2, and a benzyl amido group at R3 in the 3,4‐dihydroquinazoline backbone are closely related with the channel selectivity (T/N‐type) as well as the potency based on the discovery of 6k (KYS05090).

中文翻译：

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T 型钙通道阻滞剂的合成和 SAR 研究。第二部分

已知 3,4-二氢喹唑啉衍生物是新型有效的 T 型钙通道阻滞剂。根据 3,4-二氢喹唑啉衍生物 5c (KYS05043) 的系统变异，建立了合理的 SAR 结果。结果表明，3,4-二氢喹唑啉骨架中R1的5-(二甲氨基)戊氨基、R2的联苯基和R3的苄基氨基与通道选择性(T/N型)密切相关。以及基于 6k (KYS05090) 发现的效力。