This paper presents the efficient synthesis of 2-amino-4H-benzo[b]pyrans using mesoporous poly-melamine-formaldehyde as a polymeric heterogeneous catalyst. According to the principals of green chemistry, the reaction was performed by the planetary ball milling process at ambient and neat conditions. The heterogeneous catalyst could be reused up to five runs with no reducing of catalytic efficiency. A variety of substituted 2-amino-4H-benzo[b]pyrans were obtained in good to excellent yields under eco-friendly conditions. Other advantages of the current methodology include short reaction time, wide substrate-scope, and use of a metal-free polymeric catalyst. Also, the current method avoids the use of hazardous reagents and solvents, tedious workup and multi-step purification. This work revealed that porous organic polymers containing Lewis base sites having acceptor-donner hydrogen bonding functional groups, and high porosity could play a vital role in the promotion of the one-pot multicomponent reactions in the solid-phase synthesis.

中文翻译：

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富氮多孔有机聚合物在球磨工艺固相合成 2-氨基-4H-苯并[b]吡喃支架中的应用。

本文介绍了使用介孔聚三聚氰胺甲醛作为聚合物多相催化剂的 2-氨基-4H-苯并[b] 吡喃的有效合成。根据绿色化学原理，该反应通过行星式球磨工艺在环境和纯净条件下进行。多相催化剂最多可重复使用五次，而不会降低催化效率。在环境友好的条件下，以良好到极好的收率获得了各种取代的 2-氨基-4H-苯并 [b] 吡喃。当前方法的其他优点包括反应时间短、底物范围广以及使用无金属聚合物催化剂。此外，目前的方法避免了使用危险试剂和溶剂、繁琐的后处理和多步纯化。