An Efficient Synthesis of 6′‐methyl‐1'H‐spiro[indoline‐3,4′‐pyrimidine]‐2,2′(3'H)‐dione Derivatives

Abstract

The reactions of isatins, urea and 1‐(piperidin‐1‐yl)butane‐1,3‐dione or 1‐morpholinobutane‐1,3‐dione have been developed for the preparation of spiroheterocycles compounds. It was found these reactions could be given higher yields and required shorter time in our process. In this synthesis, some useful groups, such as pyridyl and morpholinyl were introduced into the structures of the products. The compounds were confirmed by IR, 1H NMR, 13C NMR, and HRMS. Else, compounds 4i and 4r were additionally confirmed by X‐ray diffraction analysis. The other advantages of this procure were simple handling, high yields, and wide range substrates.