Reaction #69980

Reaction equation

sodium hydrogencarbonate

4-[4-(1,4-dioxa-8-azaspiro[4.5]dec-8-yl)phenyl]-3,4-dihydro-2H-quinoxaline-1-carboxylic acid tert-butyl ester

hydrochloric acid

→

1-[4-(1,4-dioxa-8-azaspiro[4.5]dec-8-yl)phenyl]-1,2,3,4-tetrahydroquinoxaline

Yield 99.9%

Solvents

dichloromethane

dioxane

Conditions

Workup

1. 1
   ExtractionThe aqueous phase is extracted three times with dichloromethane
2. 2
   Dryingdried over sodium sulphate
3. 3
   Concentrationconcentrated under vacuum

Procedure

0.27 g of 4-[4-(1,4-dioxa-8-azaspiro[4.5]dec-8-yl)phenyl]-3,4-dihydro-2H-quinoxaline-1-carboxylic acid tert-butyl ester is placed in 3 ml of a 4N solution of hydrochloric acid in dioxane. The mixture is stirred at ambient temperature for 28 h. The reaction mixture is diluted with dichloromethane and then a saturated aqueous sodium hydrogencarbonate solution is added. The aqueous phase is extracted three times with dichloromethane. The organic phases are combined, dried over sodium sulphate and concentrated under vacuum. 0.21 g of 1-[4-(1,4-dioxa-8-azaspiro[4.5]dec-8-yl)phenyl]-1,2,3,4-tetrahydroquinoxaline is obtained.

Source