188782-82-3Relevant academic research and scientific papers
Conversion of 7-Methoxy-3,4-dihydro-2H-1-benzopyran-2-one into the corresponding dimethyl ortho ester
Bourke, David G.,Collins, David J.
, p. 3863 - 3878 (2007/10/03)
7-Methoxy-3,4-dihydro-2H-1-benzopyran-2-one 2 was converted into 3-(2'-tert-butyldimethylsilyloxy-4'-methoxyphenyl)-N-methyl-N-phenylpropanamide 25 and reaction of this with methyl trifluoromethanesulfonate, followed by reaction with sodium methoxide, gave 2,2,7-trimethoxy-2H- 1-benzopyran 1a in 55% overall yield from 25. A similar methylation/methoxide sequence using 3-(2'-benzyloxy-4-methoxyphenyl)-N-methyl-N-phenylpropanamide 18 gave a mixture which contained trimethyl 3-(2'-benzyloxy-4'-methoxyphenyl)orthopropanoate 20a and reaction of this mixture with a solution of sodium in tert-butanol gave a product in which 2,2,7-trimethoxy-2H-1-benzopyran 1a was detected, but not isolable.
