Reaction #552205

Reaction equation

methyl chloroformate

1E

2,3-dihydro-2,4-dimethyl-7-hydrazinobenzofuran

N,N-diisopropylethylamine

→

2-(2,3-dihydro-2,4-dimethylbenzofuran-7-yl)hydrazinecarboxylic acid methyl ester

Solvents

THF

Conditions

Workup

1. 1
   Extractionextracted with ether
2. 2
   DryingThe extract was dried (MgSO4)
3. 3
   Otherthe solvent was evaporated
4. 4
   Otherchromatographed on silica gel
5. 5
   workup.ADDITIONv:v mixture of tetrahydrofuran, ethyl acetate and hexane as eluent

Procedure

15.6 g of 1E was mixed with 150 ml of THF and 11.3 g of N,N-diisopropylethylamine. The mixture was cooled to -5° C. and 9.1 g of methyl chloroformate was added drop-by-drop to the stirred mixture, stirred at 0° C. for two hours, then poured over ice water and extracted with ether. The extract was dried (MgSO4) and the solvent was evaporated. The residue was column chromatographed on silica gel, using a 1:4:20 v:v:v mixture of tetrahydrofuran, ethyl acetate and hexane as eluent, to give 2-(2,3-dihydro-2,4-dimethylbenzofuran-7-yl)hydrazinecarboxylic acid methyl ester (1F), as a tan solid, m.p.: 90°-92° C.

Source