A well-known Hantzsch reaction for the synthesis of 1,4-dihydropyridine was performed in an eco-friendly manner using concentrated solar radiation. Solvent and catalyst-free approach with excellent yield is the key feature. The present mild, green, and energy-efficient method tolerates the various substrates. Multi-gram scale up (50 mmol), shorter reaction time, simple work-up procedure and high atom efficiency are the added advantages of this reported protocol.

中文翻译：

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太阳能作为制备规模以及无溶剂和无催化剂的Hantzsch反应的可再生能源

使用集中的太阳辐射以生态友好的方式进行了众所周知的用于合成1,4-二氢吡啶的Hantzsch反应。关键特性是无溶剂和无催化剂方法，具有极高的收率。当前的温和，绿色和节能方法可耐受各种基材。数克级放大（50 mmol），更短的反应时间，简单的后处理程序和高原子效率是该报道方案的附加优点。