2,3-dihydrothiochromen-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:

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

Procedure: A solution of 23.9 g of 4-thiochromanone, 30 ml of 3-buten-2-ol and 240 mg of p-toluenesulfonic acid in 30 ml of 2,2-dimethoxy-propane and 240 ml of anhydrous toluene was boiled under reflux for 20 hours. The reaction mixture was subsequently concentrated in a vacuum and purified by column chromatography on silica gel (hexane/diethyl ether 5:1). 15.3 g (48%) of (RS)-2-(2-buten-1-yl)-4-thiochromanone were obtained as a yellow oil. under reflux for 20 hours The reaction mixture was subsequently concentrated in a vacuum purified by column chromatography on silica gel (hexane/diethyl ether 5:1)

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

Procedure: A solution of 23.9 g of 4-thiochromanone, 30 ml of 3-buten-2-ol and 240 mg of p-toluenesulfonic acid in 30 ml of 2,2-dimethoxy-propane and 240 ml of anhydrous toluene was boiled under reflux for 20 hours. The reaction mixture was subsequently concentrated in a vacuum and purified by column chromatography on silica gel (hexane/diethyl ether 5:1). 15.3 g (48%) of (RS)-2-(2-buten-1-yl)-4-thiochromanone were obtained as a yellow oil. under reflux for 20 hours The reaction mixture was subsequently concentrated in a vacuum purified by column chromatography on silica gel (hexane/diethyl ether 5:1)

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

Procedure: Reduction of thiochroman-4-one with lithium aluminum hydride by the method of Preparation O, Part (iii), affords thiochroman-4-ol in like manner. This is taken up in acetic acid containing a molar excess of acetic anhydride, the mixture heated at reflux for three hours, cooled, ethanol added to quench the excess anhydride and the mixture hydrogenated by the method of Example 11.

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

Procedure: Reduction of thiochroman-4-one with lithium aluminum hydride by the method of Preparation O, Part (iii), affords thiochroman-4-ol in like manner. This is taken up in acetic acid containing a molar excess of acetic anhydride, the mixture heated at reflux for three hours, cooled, ethanol added to quench the excess anhydride and the mixture hydrogenated by the method of Example 11.

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

Procedure: The 3,4-dihydro-2-(dimethylaminomethylene)-4-thia-1(2H)-naphthalenone starting material was prepared from thiochroman-4-one (4.93 g, 26.8 mmol) and N,N-dimethylformamide diethyl acetal (23 ml, 133.8 mmol) to give the desired product as golden yellow crystals (5.15 g) m.p. 96-97°. MS (ES+) 220 (MH+, 100%).

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

Procedure: The 3,4-dihydro-2-(dimethylaminomethylene)-4-thia-1(2H)-naphthalenone starting material was prepared from thiochroman-4-one (4.93 g, 26.8 mmol) and N,N-dimethylformamide diethyl acetal (23 ml, 133.8 mmol) to give the desired product as golden yellow crystals (5.15 g) m.p. 96-97°. MS (ES+) 220 (MH+, 100%).

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

Procedure: A solution of potassium hydroxide (0.5 g) in methanol (5 ml) was added to a solution of thiochroman-4-one (0.93 g) and 5-methyl-1-(triphenylmethyl)-1H-imidazole-4-carboxaldehyde (2 g) in methanol (25 ml), and the resulting solution was stirred at 50° for 3.5 h. The resultant precipitate was filtered off, washed with methanol (20 ml) and dried to give the title compound (2.1 g), m.p. 225°-226°. The resultant precipitate was filtered off washed with methanol (20 ml) dried