Reaction #40397

Reaction equation

ethanolamine

6-benzyloxy-8-(2-ethoxy-2-hydroxyacetyl)-4H-benzo[1,4]oxazin-3-one

2-(2-chloro-4-fluorophenyl)-1,1-dimethylethylamine

lithium borohydride

boron tribromide

→

8-{2-[2-(2-chloro-4-fluorophenyl)-1,1-dimethylethylamino]-1-hydroxyethyl}-6-hydroxy-4H-benzo[1,4]oxazin-3-one

Solvents

dichloromethane

dichloromethane

dichloromethane

water

Conditions

Workup

1. 1
   Otherthus obtained
2. 2
   Otherto come up to ambient temperature
3. 3
   Filtrationfiltered through an EXTRELUT® column
4. 4
   Otherthe residue is purified by chromatography

Procedure

357 mg (1 mmol) of 6-benzyloxy-8-(2-ethoxy-2-hydroxyacetyl)-4H-benzo[1,4]oxazin-3-one and 202 mg (1 mmol) of 2-(2-chloro-4-fluorophenyl)-1,1-dimethylethylamine are reacted with lithium borohydride analogously to the method for Example 10(d). To debenzylate the ethanolamine thus obtained, it is dissolved in 3 mL of dichloromethane and cooled to −78° C. At this temperature, 2 mL of a 1 molar solution of boron tribromide in dichloromethane is added and the mixture is slowly allowed to come up to ambient temperature. The reaction mixture is combined with 10 mL dichloromethane and 3 mL water and filtered through an EXTRELUT® column. The eluate is freed from solvent and the residue is purified by chromatography. White solid. Yield: 70 mg (13%, trifluoroethyl acetate); mass spectroscopy: [M+H]+=409/11.

Source