Reaction #724814

Reaction equation

MCPBA

1G

2-(3,4-dihydro-2,5-dimethyl-2H-1-benzopyran-8-yl)hydrazinecarboxylic acid

→

(3,4-Dihydro-2,5-dimethyl-2H-1-benzopyran-8-yl)diazenecarboxylic acid methyl ester

Solvents

methylene chloride

methylene chloride

Conditions

Workup

1. 1
   Washwashed with 10% aqueous sodium carbonate solution
2. 2
   DryingThe resulting methylene chloride solution was dried (MgSO4)
3. 3
   Otherthe solvent was evaporated
4. 4
   OtherThe residue was purified by column chromatography over silica gel
5. 5
   workup.ADDITIONv:v mixture of THF, ethyl acetate and hexane as eluent
6. 6
   Otherto give 1

Procedure

A solution of 13.8 g of MCPBA in 100 ml of methylene chloride was added drop-by-drop over 10 minutes to a stirred solution of 16.1 g of 1G in 150 ml of methylene chloride at room temperature. The resulting mixture was stirred and refluxed (35° C.) for 30 minutes, then washed with 10% aqueous sodium carbonate solution. The resulting methylene chloride solution was dried (MgSO4), and the solvent was evaporated. The residue was purified by column chromatography over silica gel, using a 1:4:20 v:v:v mixture of THF, ethyl acetate and hexane as eluent, to give 1, as a brick red solid, m.p.: 95°-97° C.

Source