Reaction #724813

Reaction equation

methyl chloroformate

1F

8-hydrazino-3,4-dihydro-2,5-dimethyl-2H-1-benzopyran

N,N-diisopropyl-N-ethylamine

→

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

Solvents

THF

Conditions

Workup

1. 1
   Extractionextracted with ether
2. 2
   DryingThe extract was dried (MgSO4)
3. 3
   Concentrationconcentrated to dryness

Procedure

A stirred mixture of the 1F, 200 ml of THF and 12.4 g of N,N-diisopropyl-N-ethylamine was chilled to 0° C. and 9.1 g of methyl chloroformate was added, drop-by-drop, over five minutes. The mixture was poured over ice water and extracted with ether. The extract was dried (MgSO4) and concentrated to dryness, to give the methyl ester of 2-(3,4-dihydro-2,5-dimethyl-2H-1-benzopyran-8-yl)hydrazinecarboxylic acid (1G), as an amber syrup.

Source