Studies of bioactive heterocycles: amino Claisen rearrangement of 4-N-(4-aryloxybut-2-ynyl),N-methylaminocoumarins

Thermal amino-Claisen rearrangement of 4-N-(aryloxybut-2-ynyl),N-methyl-aminocoumarins (8a–e) in refluxing o-dichlorobenzene gave 4-aryloxymethylene-1-methyl-1,2,3-trihydropyrido[3,2-c][1]benzopyran-5-ones (9a–e) in 56–72% isolated yields. Substrates (8a–f) were prepared from 4-chlorocoumarin (6a,b) and N-(4-ary-loxybutynyl),N-methylamine (7a–f) in 68–77% yields.