6-chloro-2,3-dihydrochromen-4-one

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

Procedure: A solution of 6-chloro-3,4-dihydro-4-oxo-2H-1-benzopyran (3.285 g), N,N-dimethylformamide dimethyl acetal (8.568 g), and triethylamine (2.727 g) in benzene (36 ml) was refluxed with stirring for 1 hour and then about three-fourths of the solvent was distilled slowly at atmospheric pressure over a period of approximately 1 hour. To the residue was added benzene (36 ml) and the solvent was distilled again. The residue was dissolved in a mixture of chloroform and ethyl acetate, treated with activated charcoal, and evaporated in vacuo. The residual solid was washed with a mixture of diethyl ether and ethyl acetate to give 6-chloro-3,4-dihydro-3-dimethylaminomethylene-4-oxo-2H-1-benzopyran (2.73 g). about three-fourths of the solvent was distilled slowly at atmospheric pressure over a period of approximately 1 hour To the residue was added benzene (36 ml) the solvent was distilled again The residue was dissolved in a mixture of chloroform and ethyl acetate treated with activated charcoal evaporated in vacuo The residual solid was washed with a mixture of diethyl ether and ethyl acetate

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

Procedure: A solution of 6-chloro-3,4-dihydro-4-oxo-2H-1-benzopyran (3.285 g), N,N-dimethylformamide dimethyl acetal (8.568 g), and triethylamine (2.727 g) in benzene (36 ml) was refluxed with stirring for 1 hour and then about three-fourths of the solvent was distilled slowly at atmospheric pressure over a period of approximately 1 hour. To the residue was added benzene (36 ml) and the solvent was distilled again. The residue was dissolved in a mixture of chloroform and ethyl acetate, treated with activated charcoal, and evaporated in vacuo. The residual solid was washed with a mixture of diethyl ether and ethyl acetate to give 6-chloro-3,4-dihydro-3-dimethylaminomethylene-4-oxo-2H-1-benzopyran (2.73 g). about three-fourths of the solvent was distilled slowly at atmospheric pressure over a period of approximately 1 hour To the residue was added benzene (36 ml) the solvent was distilled again The residue was dissolved in a mixture of chloroform and ethyl acetate treated with activated charcoal evaporated in vacuo The residual solid was washed with a mixture of diethyl ether and ethyl acetate

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

Procedure: The title compound was prepared from 6-chloro-4-chromanone (9.0 g, 0.049 mole) and thallium trinitrate (0.074 mole) absorbed onto K10 clay (75 g) by the method of Description 1, as a yellow solid (1.51 g, 16%). absorbed onto K10 clay (75 g) by the method of Description 1, as a yellow solid (1.51 g, 16%)

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

Procedure: The title compound was prepared from 6-chloro-4-chromanone (9.0 g, 0.049 mole) and thallium trinitrate (0.074 mole) absorbed onto K10 clay (75 g) by the method of Description 1, as a yellow solid (1.51 g, 16%). absorbed onto K10 clay (75 g) by the method of Description 1, as a yellow solid (1.51 g, 16%)

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

Procedure: A solution of 6-chloro-3,4-dihydro-4-oxo-2H-1-benzopyran (3.285 g), N,N-dimethylformamide dimethyl acetal (8.568 g), and triethylamine (2.727 g) in benzene (36 ml) was refluxed with stirring for 1 hour and then about three-fourths of the solvent was distilled slowly at atmospheric pressure over a period of approximately 1 hour. To the residue was added benzene (36 ml) and the solvent was distilled again. The residue was dissolved in a mixture of chloroform and ethyl acetate, treated with activated charcoal, and evaporated in vacuo. The residual solid was washed with a mixture of diethyl ether and ethyl acetate to give 6-chloro-3,4-dihydro-3-dimethylaminomethylene-4-oxo-2H-1-benzopyran (2.73 g). about three-fourths of the solvent was distilled slowly at atmospheric pressure over a period of approximately 1 hour To the residue was added benzene (36 ml) the solvent was distilled again The residue was dissolved in a mixture of chloroform and ethyl acetate treated with activated charcoal evaporated in vacuo The residual solid was washed with a mixture of diethyl ether and ethyl acetate

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

Procedure: A solution of 6-chloro-3,4-dihydro-4-oxo-2H-1-benzopyran (3.285 g), N,N-dimethylformamide dimethyl acetal (8.568 g), and triethylamine (2.727 g) in benzene (36 ml) was refluxed with stirring for 1 hour and then about three-fourths of the solvent was distilled slowly at atmospheric pressure over a period of approximately 1 hour. To the residue was added benzene (36 ml) and the solvent was distilled again. The residue was dissolved in a mixture of chloroform and ethyl acetate, treated with activated charcoal, and evaporated in vacuo. The residual solid was washed with a mixture of diethyl ether and ethyl acetate to give 6-chloro-3,4-dihydro-3-dimethylaminomethylene-4-oxo-2H-1-benzopyran (2.73 g). about three-fourths of the solvent was distilled slowly at atmospheric pressure over a period of approximately 1 hour To the residue was added benzene (36 ml) the solvent was distilled again The residue was dissolved in a mixture of chloroform and ethyl acetate treated with activated charcoal evaporated in vacuo The residual solid was washed with a mixture of diethyl ether and ethyl acetate

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

Procedure: A solution of 6-chloro-3,4-dihydro-4-oxo-2H-1-benzopyran (3.285 g), N,N-dimethylformamide dimethyl acetal (8.568 g), and triethylamine (2.727 g) in benzene (36 ml) was refluxed with stirring for 1 hour and then about three-fourths of the solvent was distilled slowly at atmospheric pressure over a period of approximately 1 hour. To the residue was added benzene (36 ml) and the solvent was distilled again. The residue was dissolved in a mixture of chloroform and ethyl acetate, treated with activated charcoal, and evaporated in vacuo. The residual solid was washed with a mixture of diethyl ether and ethyl acetate to give 6-chloro-3,4-dihydro-3-dimethylaminomethylene-4-oxo-2H-1-benzopyran (2.73 g). about three-fourths of the solvent was distilled slowly at atmospheric pressure over a period of approximately 1 hour To the residue was added benzene (36 ml) the solvent was distilled again The residue was dissolved in a mixture of chloroform and ethyl acetate treated with activated charcoal evaporated in vacuo The residual solid was washed with a mixture of diethyl ether and ethyl acetate

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

Procedure: The title compound was prepared from 6-chloro-4-chromanone (9.0 g, 0.049 mole) and thallium trinitrate (0.074 mole) absorbed onto K10 clay (75 g) by the method of Description 1, as a yellow solid (1.51 g, 16%). absorbed onto K10 clay (75 g) by the method of Description 1, as a yellow solid (1.51 g, 16%)