Herewith a new process concept for synthesis is presented which combines both UV-photoirradiation and high-p,T intensification (photo-high-p,T) in continuous flow. The application of this procedure to Vitamin D3 synthesis promotes thermal shifting of the equilibrium from the reaction intermediate to the product. This is enabled by microreactors which allow operation under harsh conditions such as the high temperature used here. This provides, to our best knowledge, a new kind of process combination (novel process window). As a result, in less than 1 min, 42% conversion of 7-dehydrocholesterol can be achieved giving a 17% yield and 40% selectivity of Vitamin D3. This approach enhances productivity by up to 2 orders of magnitude compared with the current capillary based vitamin D3 synthesis, because, under the microflow conditions, photochemistry can be performed at fairly high concentration and up to 20 times faster.

中文翻译：

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使用紫外线灯对维生素D3的合成进行微流高p，T强化。

因此，提出了一种新的合成工艺方法，该方法结合了紫外光照射和连续流动中的高p，T增强（photo-high-p，T）。该方法在维生素D3合成中的应用促进了平衡从反应中间体到产物的热转移。微型反应器可实现这一点，该微型反应器可在苛刻的条件下运行，例如此处使用的高温。据我们所知，这提供了一种新型的过程组合（新颖的过程窗口）。结果，在不到1分钟的时间内，可以实现42％的7-脱氢胆固醇转化率，从而获得17％的产率和40％的维生素D3选择性。与目前基于毛细管的维生素D3合成方法相比，该方法可将生产率提高多达2个数量级，因为在微流条件下，