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  • 1 National Institute of Advanced Industrial Science and Technology (AIST) Ibaraki Tsukuba 305–8565, Japan
  • 2 Present address. T.H.: HGST Japan, Ltd., 1, Kirihara, Fujisawa, Kanagawa 252–8588, Japan; M.K.: Asahi Kasei Fibers Co., 5–4960, Nakagawara, Nobeoka, Miyazaki 882–0031, Japan; T.S.: UNISOKU Co. Ltd., 2-4-3, Kasugano, Hirakata, Osaka 573–0131, Japan; C.L.: Shanghai Institute of Technology, 100 Haiquan Rd., Shanghai, 201418, China
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A microchannel reactor was used for suppressing undesirable side reactions in a photochemical reaction. A two-step photolysis, flavone (1) → flavanone (2) → salicylic acid (3b), was conducted in a microchannel reactor using a two-phase photolysis, that is, 1 and NaBH4 were dissolved in immiscible H2O and hexane, respectively, and photolyses were conducted at their interface. The two-step photolysis product 3b was obtained as a major product. In contrast, photolysis in homogeneous EtOH solution gave flavanol (4) as a major product. The thermal side reaction 2 → 4 was suppressed completely by the interface photolysis, and a greater than 25-fold increase was observed in the selectivity of 3b.

Supplementary Materials

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