ethyl 3,4-dihydro-2H-1,4-benzoxazine-3-carboxylate

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 4.0 g of 3(R,S)-ethoxycarbonyl-3,4-dihydro-2H-1,4-benzoxazine (Example 20)) are stirred together with 0.8 g of magnesium powder in 100 ml of methanol at room temperature for 2 h. When the exothermic reaction has ended, the mixture is concentrated, the residue is taken up in methylene chloride and the organic phase is washed with 0.1N hydrochloric acid. After customary working up, the crude product is purified over 250 g of silica gel (mobile phase B): Rf (B)=0.26. When the exothermic reaction the mixture is concentrated the organic phase is washed with 0.1N hydrochloric acid the crude product is purified over 250 g of silica gel (mobile phase B)

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 4.0 g of 3(R,S)-ethoxycarbonyl-3,4-dihydro-2H-1,4-benzoxazine (Example 20)) are stirred together with 0.8 g of magnesium powder in 100 ml of methanol at room temperature for 2 h. When the exothermic reaction has ended, the mixture is concentrated, the residue is taken up in methylene chloride and the organic phase is washed with 0.1N hydrochloric acid. After customary working up, the crude product is purified over 250 g of silica gel (mobile phase B): Rf (B)=0.26. When the exothermic reaction the mixture is concentrated the organic phase is washed with 0.1N hydrochloric acid the crude product is purified over 250 g of silica gel (mobile phase B)