Reaction #2320131

Reaction equation

hydroxylamine hydrochloride

2-ethoxy-3-methyl-3,4,5,6-tetrahydrobenzo[h]chromene

→

5,6-dihydrobenzo[h]quinoline

Yield 48.3%

Solvents

acetonitrile

Conditions

Workup

1. 1
   TemperatureThe reaction mixture was heated
2. 2
   Temperatureat reflux under nitrogen
3. 3
   OtherEvaporation of the acetonitrile
4. 4
   workup.DISTILLATIONfollowed by vacuum distillation of the product
5. 5
   Otheryielded 34.5 g of a crude product that
6. 6
   Otherwas further purified by silica gel chromatography with 5/95 ethyl acetate/hexane as the eluent

Procedure

To a suspension of hydroxylamine hydrochloride (46.1 g, 0.663 mol) in 1070 mL of acetonitrile was added 2-ethoxy-3-methyl-3,4,5,6-tetrahydrobenzo[h]chromene (140 g, 0.265 mol) from step two. The reaction mixture was heated at reflux under nitrogen with stirring for 16 h. Evaporation of the acetonitrile, followed by vacuum distillation of the product yielded 34.5 g of a crude product that was further purified by silica gel chromatography with 5/95 ethyl acetate/hexane as the eluent, yielding 23.2 g (45%) of 5,6-dihydrobenzo[h]quinoline as a yellow liquid.

Source