1,4-BENZODIOXIN-2N3H)-ONE AND SOME OF ITS DERIVATIVES

The methods of synthesis of 1,4-benzodioxin-2(3H)-one have been reexam ined. Frequently quoted in the literature the method of Ghosh has been found to give impure (2-hydroxyphenoxy)acetic acid rather than the la ctone. Using various methods some simple derivatives of the title lact one substituted in the benzene ring have been prepared and characteriz ed. The bromination of the lactone with NBS gives predominantly 7-brom o-1,4-benzodioxin-2(3H)-one under electrophilic conditions, while 6-br omo-1,4-benzodioxin-2(3H)-one is obtained as a major isomer under phot olytic conditions.