Reaction #40391

Reaction equation

water

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

ethyl 4-[4-(2-amino-2-methylpropyl)phenoxy]butyrate

oxalic acid

→

ethyl 4-(4-{2-[2-(6-benzyloxy-3-oxo-3,4-dihydro-2H-benzo[1,4]oxazin-8-yl)2-hydroxyethylamino]-2-methylpropyl}phenoxy)butyrate

Solvents

diethyl ether

ethyl acetate

Conditions

Workup

1. 1
   Otherthe solid precipitated
2. 2
   Filtrationfiltered
3. 3
   Washwashed with diethyl ether

Procedure

1.20 g (3.36 mmol) of benzyloxy-8-(2-ethoxy-2-hydroxyacetyl)-4H-benzo[1,4]oxazin-3-one and 0.90 g (3.22 mmol) of ethyl 4-[4-(2-amino-2-methylpropyl)phenoxy]butyrate are reacted in the manner described for Example 8(d). The crude product is dissolved in 10 mL ethyl acetate and 10 mL water and combined with oxalic acid with stirring. The solution is diluted with diethyl ether and the solid precipitated is suction filtered and washed with diethyl ether. Yield: 1.20 g (54%, oxalate); melting point 223° C.-227° C.

Source