Reaction #40386

Reaction equation

acetone

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

2-(4-ethoxyphenyl)-1,1-dimethylethylamine

sodium borohydride

→

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

Solvents

ethanol

acetic acid

Conditions

Workup

1. 1
   workup.STIRRINGstirred for 30 minutes
2. 2
   Otherevaporated down
3. 3
   OtherThe organic phase is separated off
4. 4
   Washwashed with water
5. 5
   Dryingdried with sodium sulfate
6. 6
   workup.DISSOLUTIONThe residue is dissolved again in ethyl acetate
7. 7
   workup.ADDITIONdiluted with diethyl ether
8. 8
   OtherThe solid precipitated
9. 9
   Filtrationfiltered
10. 10
    Washwashed with diethyl ether

Procedure

2.14 g (6.0 mmol) of 6-benzyloxy-8-(2-ethoxy-2-hydroxyacetyl)-4H-benzo[1,4]oxazin-3-one and 1.0 g (5.2 mmol) of 2-(4-ethoxyphenyl)-1,1-dimethylethylamine are stirred in 40 mL ethanol for one hour at 50° C.-80° C. After cooling to ambient temperature, 0.23 g (6.0 mmol) of sodium borohydride are added and the mixture is stirred for a further hour. The reaction mixture is combined with 5 mL acetone, stirred for 30 minutes, acidified with glacial acetic acid, and evaporated down. The residue is combined with water and ethyl acetate and made alkaline. The organic phase is separated off, washed with water, dried with sodium sulfate, and freed from solvent in vacuo. The residue is dissolved again in ethyl acetate and water, combined with concentrated hydrochloric acid, and diluted with diethyl ether. The solid precipitated is suction filtered and washed with diethyl ether. White solid. Yield: 2.0 g (61%, hydrochloride); melting point: 214° C.-216° C.

Source