8-bromo-1,4-dioxaspiro[4.5]decane

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

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

Procedure: Carbon tetrabromide (11.0 g, 33.2 mmol) was added to a solution of triphenylphosphine (8.70 g, 33.2 mmol), imidazole (2.47 g, 36.3 mmol), and 1,4-dioxaspiro[4.5]decan-8-ol (5.0 g, 31.6 mmol) in DCM (150 mL) under argon at 0° C. The ice bath was removed and the mixture was stirred for 24 h at RT. The solvent was removed in vacuo to give an oil that was purified by silica gel chromatography to give 8-Bromo-1,4-dioxaspiro[4.5]decane. The ice bath was removed The solvent was removed in vacuo to give an oil that was purified by silica gel chromatography

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

Procedure: This compound is prepared in a manner analogous to that of Step B of Example 6, using 22.1 grams (0.09 mole) of the Grignard reagent of 8-bromo-1,4-dioxaspiro[4.5]decane and 17.4 grams (0.10 mole) of 3-trifluoromethylbenzaldehyde in tetrahydrofuran. Upon completion of the reaction, the reaction mixture is poured into a mixture of 100 grams of ice, 100 mL of an aqueous solution saturated with ammonium chloride, and 200 mL of diethyl ether. This mixture is filtered and the organic layer is separated. The organic layer is concentrated under reduced pressure, yielding [(1,4-dioxaspiro[4.5]decan-8-yl)(3-trifluoromethylphenyl)]methanol. This compound is prepared in a manner analogous to that of Step B of Example 6 Upon completion of the reaction This mixture is filtered the organic layer is separated The organic layer is concentrated under reduced pressure

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

Procedure: This compound is prepared in a manner analogous to that of Step B of Example 6, using 22.1 grams (0.09 mole) of the Grignard reagent of 8-bromo-1,4-dioxaspiro[4.5]decane and 17.4 grams (0.10 mole) of 3-trifluoromethylbenzaldehyde in tetrahydrofuran. Upon completion of the reaction, the reaction mixture is poured into a mixture of 100 grams of ice, 100 mL of an aqueous solution saturated with ammonium chloride, and 200 mL of diethyl ether. This mixture is filtered and the organic layer is separated. The organic layer is concentrated under reduced pressure, yielding [(1,4-dioxaspiro[4.5]decan-8-yl)(3-trifluoromethylphenyl)]methanol. This compound is prepared in a manner analogous to that of Step B of Example 6 Upon completion of the reaction This mixture is filtered the organic layer is separated The organic layer is concentrated under reduced pressure

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

Procedure: A stirred solution of 17.4 grams (0.11 mole) of 1,4-dioxaspiro[4.5]decan-8-ol (prepared as in Step B of Example 8) and 46.2 grams (0.14 mole) of freshly recrystallized carbon tetrabromide in 100 mL of methylene chloride is cooled to about 0° C., and a solution of 32.3 grams (0.12 mole) of triphenylphosphine in 50 mL of methylene chloride is added dropwise. Upon completion of addition, the reaction mixture is allowed to warm to ambient temperature where it is stirred for about 18 hours. After this time the reaction mixture is concentrated to about one quarter of the original volume. The concentrate is then passed through a pad of silica gel. Elution is accomplished with heptane. The eluate is concentrated under reduced pressure, yielding 8-bromo-1,4-dioxaspiro[4.5]decane. Upon completion of addition After this time the reaction mixture is concentrated to about one quarter of the original volume Elution The eluate is concentrated under reduced pressure

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

Procedure: When the bridging group is carbonyl, the Grignard reagent of 8-bromo-1,4-dioxaspiro[4.5]decane is first prepared. The precursor 8-bromo-1,4-dioxaspiro[4.5]decane is prepared by the method of E. I. Snyder (JOC, 36, 403 (1971)). The Grignard reagent is in turn reacted with an appropriately substituted or unsubstituted benzaldehyde, for example, 3-trifluoromethylbenzaldehyde and then treated with aqueous ammonium chloride, yielding [(1,4-dioxaspiro[4.5]decan-8-yl)(phenyl)]methanol. The so-prepared alcohol is treated with sodium hydride in toluene, and then is reacted with phenylmethyl bromide, yielding phenylmethyl [(1,4-dioxaspiro[4.5]decan-8-yl)(phenyl)]methyl ether. The 1,4-dioxaspiro functional group is then cleaved from the so-prepared molecule with acetic acid and water, as previously described, affording the corresponding phenylmethyl [(cyclohexanon-4-yl)(phenyl)]methyl ether. The ether is then reacted with cyanoguanidine, as previously described, yielding the appropriate 2,4-diamino-6-[(phenylmethoxy)(phenyl)methyl]-5,6,7,8-tetrahydroquinazoline. The tetrahydroquinazoline is then cleaved with hydrogen gas in the presence of 5% palladium on charcoal, yielding the corresponding [(2,4-diamino-5,6,7,8-tetrahydroquinazolin-6-yl)(phenyl)]methanol. Using the method of D. Swern (Tetrahedron, 34, 1651-1660 (1978)), the methanol is oxidized with oxalyl chloride and dimethyl sulfoxide in methylene chloride, yielding the targeted 2,4-diamino-6-phenylcarbonyl-5,6,7,8-tetrahydroquinazoline. Example 9 provides a detailed description of how this reaction is conducted.

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

Procedure: When the bridging group is carbonyl, the Grignard reagent of 8-bromo-1,4-dioxaspiro[4.5]decane is first prepared. The precursor 8-bromo-1,4-dioxaspiro[4.5]decane is prepared by the method of E. I. Snyder (JOC, 36, 403 (1971)). The Grignard reagent is in turn reacted with an appropriately substituted or unsubstituted benzaldehyde, for example, 3-trifluoromethylbenzaldehyde and then treated with aqueous ammonium chloride, yielding [(1,4-dioxaspiro[4.5]decan-8-yl)(phenyl)]methanol. The so-prepared alcohol is treated with sodium hydride in toluene, and then is reacted with phenylmethyl bromide, yielding phenylmethyl [(1,4-dioxaspiro[4.5]decan-8-yl)(phenyl)]methyl ether. The 1,4-dioxaspiro functional group is then cleaved from the so-prepared molecule with acetic acid and water, as previously described, affording the corresponding phenylmethyl [(cyclohexanon-4-yl)(phenyl)]methyl ether. The ether is then reacted with cyanoguanidine, as previously described, yielding the appropriate 2,4-diamino-6-[(phenylmethoxy)(phenyl)methyl]-5,6,7,8-tetrahydroquinazoline. The tetrahydroquinazoline is then cleaved with hydrogen gas in the presence of 5% palladium on charcoal, yielding the corresponding [(2,4-diamino-5,6,7,8-tetrahydroquinazolin-6-yl)(phenyl)]methanol. Using the method of D. Swern (Tetrahedron, 34, 1651-1660 (1978)), the methanol is oxidized with oxalyl chloride and dimethyl sulfoxide in methylene chloride, yielding the targeted 2,4-diamino-6-phenylcarbonyl-5,6,7,8-tetrahydroquinazoline. Example 9 provides a detailed description of how this reaction is conducted.

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

Procedure: Carbon tetrabromide (11.0 g, 33.2 mmol) was added to a solution of triphenylphosphine (8.70 g, 33.2 mmol), imidazole (2.47 g, 36.3 mmol), and 1,4-dioxaspiro[4.5]decan-8-ol (5.0 g, 31.6 mmol) in DCM (150 mL) under argon at 0° C. The ice bath was removed and the mixture was stirred for 24 h at RT. The solvent was removed in vacuo to give an oil that was purified by silica gel chromatography to give 8-Bromo-1,4-dioxaspiro[4.5]decane. The ice bath was removed The solvent was removed in vacuo to give an oil that was purified by silica gel chromatography

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

Procedure: Carbon tetrabromide (11.0 g, 33.2 mmol) was added to a solution of triphenylphosphine (8.70 g, 33.2 mmol), imidazole (2.47 g, 36.3 mmol), and 1,4-dioxaspiro[4.5]decan-8-ol (5.0 g, 31.6 mmol) in DCM (150 mL) under argon at 0° C. The ice bath was removed and the mixture was stirred for 24 h at RT. The solvent was removed in vacuo to give an oil that was purified by silica gel chromatography to give 8-Bromo-1,4-dioxaspiro[4.5]decane. The ice bath was removed The solvent was removed in vacuo to give an oil that was purified by silica gel chromatography

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

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

Procedure: Carbon tetrabromide (11.0 g, 33.2 mmol) was added to a solution of triphenylphosphine (8.70 g, 33.2 mmol), imidazole (2.47 g, 36.3 mmol), and 1,4-dioxaspiro[4.5]decan-8-ol (5.0 g, 31.6 mmol) in DCM (150 mL) under argon at 0° C. The ice bath was removed and the mixture was stirred for 24 h at RT. The solvent was removed in vacuo to give an oil that was purified by silica gel chromatography to give 8-Bromo-1,4-dioxaspiro[4.5]decane. The ice bath was removed The solvent was removed in vacuo to give an oil that was purified by silica gel chromatography

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

Procedure: This compound is prepared in a manner analogous to that of Step B of Example 6, using 22.1 grams (0.09 mole) of the Grignard reagent of 8-bromo-1,4-dioxaspiro[4.5]decane and 17.4 grams (0.10 mole) of 3-trifluoromethylbenzaldehyde in tetrahydrofuran. Upon completion of the reaction, the reaction mixture is poured into a mixture of 100 grams of ice, 100 mL of an aqueous solution saturated with ammonium chloride, and 200 mL of diethyl ether. This mixture is filtered and the organic layer is separated. The organic layer is concentrated under reduced pressure, yielding [(1,4-dioxaspiro[4.5]decan-8-yl) (3-trifluoromethylphenyl)]methanol. Step D Synthesis of phenylmethyl [(1,4-dioxaspiro[4.5]decan-8-yl)(3-trifluoromethylphenyl)]methyl ether as an intermediate This compound is prepared in a manner analogous to that of Step B of Example 6 Upon completion of the reaction This mixture is filtered the organic layer is separated The organic layer is concentrated under reduced pressure