Chloroacetyl chloride → Methyl 3-oxo-3,4-dihydro-2H-1,4-benzoxazine-6-carboxylate

Participants

Reaction Conditions

Reaction Steps

In a 250 ml three-necked round-bottomed flask were placed methyl 3-amino-4-hydroxybenzoate (5 g, 30 mmole), benzyltriethylammonium chloride (6.8 g, 30 mmole), chloroform (75 ml) and powdered sodium bicarbonate (10.1 g, 120 mmole). The resulting mixture was cooled down to 0° C. and a solution of chloroacetyl chloride (4.1 g, 36 mmole) in chloroform (20 ml) was added dropwise at such a rate as to keep the reaction temperature between 0° C. to 3° C. After the addition was complete the reaction mixture was stirred at 0° C. for another 90 minutes, followed by slow heating to 55° C., kept at that temperature for 8 hours, and finally stirred at room temperature overnight. The solvent was removed in a rotary evaporator, the resulting crude product was taken up in water, shaken and filtered yielding, after drying in a vacuum oven, 5.8 g of the expected methyl 1,4-benzoxazine-3-one-6-carboxylate which was used in the next step without further purification.

Provenance & Evidence