3-amino-2,3-dihydrochromen-4-one;hydrochloride

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

Procedure: Chloroacetyl chloride (41.6 g, 368 mmol) was added to a solution of 3-amino-chroman-4-one hydrochloride (67 g, 335 mmol) and triethylamine (102 g, 1.01 mol) in tetrahydrofuran (700 ml) and the mixture was stirred for one hour. The solution was partitioned between water and ethyl acetate. The organic layer was washed with brine, dried over magnesium sulfate, and concentrated under reduced pressure. The residue was purified by silica gel column chromatography (eluent; 5-10% methanol in chloroform) to afford 2-chloro-N-(4-oxo-chroman-3-yl)-acetamide (22.6 g, 94.3 mmol, 28%) as white crystals. The solution was partitioned between water and ethyl acetate The organic layer was washed with brine dried over magnesium sulfate concentrated under reduced pressure The residue was purified by silica gel column chromatography (eluent; 5-10% methanol in chloroform)

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

Procedure: Chloroacetyl chloride (41.6 g, 368 mmol) was added to a solution of 3-amino-chroman-4-one hydrochloride (67 g, 335 mmol) and triethylamine (102 g, 1.01 mol) in tetrahydrofuran (700 ml) and the mixture was stirred for one hour. The solution was partitioned between water and ethyl acetate. The organic layer was washed with brine, dried over magnesium sulfate, and concentrated under reduced pressure. The residue was purified by silica gel column chromatography (eluent; 5-10% methanol in chloroform) to afford 2-chloro-N-(4-oxo-chroman-3-yl)-acetamide (22.6 g, 94.3 mmol, 28%) as white crystals. The solution was partitioned between water and ethyl acetate The organic layer was washed with brine dried over magnesium sulfate concentrated under reduced pressure The residue was purified by silica gel column chromatography (eluent; 5-10% methanol in chloroform)

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

Procedure: Chloroacetyl chloride (41.6 g, 368 mmol) was added to a solution of 3-amino-chroman-4-one hydrochloride (67 g, 335 mmol) and triethylamine (102 g, 1.01 mol) in tetrahydrofuran (700 ml) and the mixture was stirred for one hour. The solution was partitioned between water and ethyl acetate. The organic layer was washed with brine, dried over magnesium sulfate, and concentrated under reduced pressure. The residue was purified by silica gel column chromatography (eluent; 5-10% methanol in chloroform) to afford 2-chloro-N-(4-oxo-chroman-3-yl)-acetamide (22.6 g, 94.3 mmol, 28%) as white crystals. The solution was partitioned between water and ethyl acetate The organic layer was washed with brine dried over magnesium sulfate concentrated under reduced pressure The residue was purified by silica gel column chromatography (eluent; 5-10% methanol in chloroform)