2,2-dimethyl-3H-chromen-4-one

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

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

Procedure: Twenty five grams (25 g) of 2-hydroxyacetophenon, 10.7 g of acetone, and 5.5 g of pyrrolidine were added to 50 ml of toluene, and heated and refluxed. Twenty hours later, the temperature was returned to ambient temperature and the solvent was distilled off under reduced pressure, to which was added 100 ml of 1N hydrogen chloride. The extraction was carried out with 50 ml×3 of chloroform, followed by washing in water, drying over anhydrous magnesium sulfate, filtering off and condensation of the filtered solution. The residue was purified on a silica gel column the fraction containing the purified product were mixed together and the solvent therein was distilled off under reduced pressure to obtain 7 g of 3,4-dihydro-2,2-dimethyl-2H-benzo[b]pyran-4-one. heated refluxed Twenty hours was returned to ambient temperature the solvent was distilled off under reduced pressure, to which was added 100 ml of 1N hydrogen chloride The extraction by washing in water drying over anhydrous magnesium sulfate filtering off condensation of the filtered solution The residue was purified on a silica gel column the fraction containing the purified product were mixed together the solvent therein was distilled off under reduced pressure

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

Procedure: Twenty five grams (25 g) of 2-hydroxyacetophenon, 10.7 g of acetone, and 5.5 g of pyrrolidine were added to 50 ml of toluene, and heated and refluxed. Twenty hours later, the temperature was returned to ambient temperature and the solvent was distilled off under reduced pressure, to which was added 100 ml of 1N hydrogen chloride. The extraction was carried out with 50 ml×3 of chloroform, followed by washing in water, drying over anhydrous magnesium sulfate, filtering off and condensation of the filtered solution. The residue was purified on a silica gel column the fraction containing the purified product were mixed together and the solvent therein was distilled off under reduced pressure to obtain 7 g of 3,4-dihydro-2,2-dimethyl-2H-benzo[b]pyran-4-one. heated refluxed Twenty hours was returned to ambient temperature the solvent was distilled off under reduced pressure, to which was added 100 ml of 1N hydrogen chloride The extraction by washing in water drying over anhydrous magnesium sulfate filtering off condensation of the filtered solution The residue was purified on a silica gel column the fraction containing the purified product were mixed together the solvent therein was distilled off under reduced pressure

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

Procedure: Twenty five grams (25 g) of 2-hydroxyacetophenon, 10.7 g of acetone, and 5.5 g of pyrrolidine were added to 50 ml of toluene, and heated and refluxed. Twenty hours later, the temperature was returned to ambient temperature and the solvent was distilled off under reduced pressure, to which was added 100 ml of 1N hydrogen chloride. The extraction was carried out with 50 ml×3 of chloroform, followed by washing in water, drying over anhydrous magnesium sulfate, filtering off and condensation of the filtered solution. The residue was purified on a silica gel column the fraction containing the purified product were mixed together and the solvent therein was distilled off under reduced pressure to obtain 7 g of 3,4-dihydro-2,2-dimethyl-2H-benzo[b]pyran-4-one. heated refluxed Twenty hours was returned to ambient temperature the solvent was distilled off under reduced pressure, to which was added 100 ml of 1N hydrogen chloride The extraction by washing in water drying over anhydrous magnesium sulfate filtering off condensation of the filtered solution The residue was purified on a silica gel column the fraction containing the purified product were mixed together the solvent therein was distilled off under reduced pressure

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

Procedure: Twenty five grams (25 g) of 2-hydroxyacetophenon, 10.7 g of acetone, and 5.5 g of pyrrolidine were added to 50 ml of toluene, and heated and refluxed. Twenty hours later, the temperature was returned to ambient temperature and the solvent was distilled off under reduced pressure, to which was added 100 ml of 1N hydrogen chloride. The extraction was carried out with 50 ml×3 of chloroform, followed by washing in water, drying over anhydrous magnesium sulfate, filtering off and condensation of the filtered solution. The residue was purified on a silica gel column the fraction containing the purified product were mixed together and the solvent therein was distilled off under reduced pressure to obtain 7 g of 3,4-dihydro-2,2-dimethyl-2H-benzo[b]pyran-4-one. heated refluxed Twenty hours was returned to ambient temperature the solvent was distilled off under reduced pressure, to which was added 100 ml of 1N hydrogen chloride The extraction by washing in water drying over anhydrous magnesium sulfate filtering off condensation of the filtered solution The residue was purified on a silica gel column the fraction containing the purified product were mixed together the solvent therein was distilled off under reduced pressure

Conditions: temp:82.51; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A reaction mixture prepared from 10 mmol of 2,2-dimethyl-4-chromanone, 12 mmol of hydroxylamine hydrochloride in 5 ml of methanol and 5 ml of pyridine is heated with stirring over the course of 2 hours to 80-85° C., the solvent is distilled off on a rotary evaporator and the oily residue is crystallized under water. is heated the solvent is distilled off on a rotary evaporator the oily residue is crystallized under water

Conditions: temp:82.51; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A reaction mixture prepared from 10 mmol of 2,2-dimethyl-4-chromanone, 12 mmol of hydroxylamine hydrochloride in 5 ml of methanol and 5 ml of pyridine is heated with stirring over the course of 2 hours to 80-85° C., the solvent is distilled off on a rotary evaporator and the oily residue is crystallized under water. is heated the solvent is distilled off on a rotary evaporator the oily residue is crystallized under water

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

Procedure: The title compound was prepared from 2,2-dimethylchroman-4-one according to the method described in Example 2B. MS (LCMS) m/z 236 (M+H2O+CH3CN)+.

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

Procedure: Twenty five grams (25 g) of 2-hydroxyacetophenon, 10.7 g of acetone, and 5.5 g of pyrrolidine were added to 50 ml of toluene, and heated and refluxed. Twenty hours later, the temperature was returned to ambient temperature and the solvent was distilled off under reduced pressure, to which was added 100 ml of 1N hydrogen chloride. The extraction was carried out with 50 ml×3 of chloroform, followed by washing in water, drying over anhydrous magnesium sulfate, filtering off and condensation of the filtered solution. The residue was purified on a silica gel column the fraction containing the purified product were mixed together and the solvent therein was distilled off under reduced pressure to obtain 7 g of 3,4-dihydro-2,2-dimethyl-2H-benzo[b]pyran-4-one. heated refluxed Twenty hours was returned to ambient temperature the solvent was distilled off under reduced pressure, to which was added 100 ml of 1N hydrogen chloride The extraction by washing in water drying over anhydrous magnesium sulfate filtering off condensation of the filtered solution The residue was purified on a silica gel column the fraction containing the purified product were mixed together the solvent therein was distilled off under reduced pressure