Cyclization of N,N'-diethylurea (I) with cyanoacetic acid (II) in hot acetic anhydride gives 6-amino-1,3-diethyluracil (III) which is nitrosated with NaNO2/HOAc in water to yield 6-amino-1,3-diethyl-5-nitrosouracil (IV). The reduction of (IV) with Na2S2O4 and K2CO3 in concentrated aqueous ammonia affords 5,6-diamino-1,3-diethyluracil (V), which is condensed with either 3-(3,4-dimethoxyphenyl)-2(E)-propenoyl chloride (VI) in EtOH/water or 3-(3,4-dimethoxyphenyl)-2(E)-propenoic acid (VII) and 3-[3-(diethylamino)propyl]-1-ethylcarbodiimide (EDAC) in dioxane/water to provide the corresponding amide (VIII). Cyclization of (VIII) by means of NaOH in the same solvent furnishes the xanthine derivative (IX), which is finally methylated with methyl iodide and K2CO3 in DMF.

Acylation of 5,6-diamino-1,3-dimethyluracil (I) with 4-methoxy-2,3-dimethylcinnamic acid (II) in the presence of EDC gave amide (III). This was then cyclized under basic conditions to afford the styryltheophylline derivative (IV). Finally, methylation of (IV) with iodomethane and K2CO3 furnished the title caffeine derivative.

Cyclization of N,N'-diethylurea (I) with cyanoacetic acid (II) in hot acetic anhydride gives 6-amino-1,3-diethyluracil (III) which is nitrosated with NaNO2/HOAc in water to yield 6-amino-1,3-diethyl-5-nitrosouracil (IV). The reduction of (IV) with Na2S2O4 and K2CO3 in concentrated aqueous ammonia affords 5,6-diamino-1,3-diethyluracil (V), which is condensed with either 3-(3,4-dimethoxyphenyl)-2(E)-propenoyl chloride (VI) in EtOH/water or 3-(3,4-dimethoxyphenyl)-2(E)-propenoic acid (VII) and 3-[3-(diethylamino)propyl]-1-ethylcarbodiimide (EDAC) in dioxane/water to provide the corresponding amide (VIII). Cyclization of (VIII) by means of NaOH in the same solvent furnishes the xanthine derivative (IX), which is finally methylated with methyl iodide and K2CO3 in DMF.

Acylation of 5,6-diamino-1,3-dimethyluracil (I) with 4-methoxy-2,3-dimethylcinnamic acid (II) in the presence of EDC gave amide (III). This was then cyclized under basic conditions to afford the styryltheophylline derivative (IV). Finally, methylation of (IV) with iodomethane and K2CO3 furnished the title caffeine derivative.

Cyclization of N,N'-diethylurea (I) with cyanoacetic acid (II) in hot acetic anhydride gives 6-amino-1,3-diethyluracil (III) which is nitrosated with NaNO2/HOAc in water to yield 6-amino-1,3-diethyl-5-nitrosouracil (IV). The reduction of (IV) with Na2S2O4 and K2CO3 in concentrated aqueous ammonia affords 5,6-diamino-1,3-diethyluracil (V), which is condensed with either 3-(3,4-dimethoxyphenyl)-2(E)-propenoyl chloride (VI) in EtOH/water or 3-(3,4-dimethoxyphenyl)-2(E)-propenoic acid (VII) and 3-[3-(diethylamino)propyl]-1-ethylcarbodiimide (EDAC) in dioxane/water to provide the corresponding amide (VIII). Cyclization of (VIII) by means of NaOH in the same solvent furnishes the xanthine derivative (IX), which is finally methylated with methyl iodide and K2CO3 in DMF.

Cyclization of N,N'-diethylurea (I) with cyanoacetic acid (II) in hot acetic anhydride gives 6-amino-1,3-diethyluracil (III) which is nitrosated with NaNO2/HOAc in water to yield 6-amino-1,3-diethyl-5-nitrosouracil (IV). The reduction of (IV) with Na2S2O4 and K2CO3 in concentrated aqueous ammonia affords 5,6-diamino-1,3-diethyluracil (V), which is condensed with either 3-(3,4-dimethoxyphenyl)-2(E)-propenoyl chloride (VI) in EtOH/water or 3-(3,4-dimethoxyphenyl)-2(E)-propenoic acid (VII) and 3-[3-(diethylamino)propyl]-1-ethylcarbodiimide (EDAC) in dioxane/water to provide the corresponding amide (VIII). Cyclization of (VIII) by means of NaOH in the same solvent furnishes the xanthine derivative (IX), which is finally methylated with methyl iodide and K2CO3 in DMF.

This compound has been obtained by methylation of 1,3-diethyl-8-[2(E)-(4-hydroxy-3-methoxyphenyl)vinyl]-7-methylxanthine (I) (KF-23325) with 11C methyl iodide and NaOH in DMF.

Cyclization of N,N'-diethylurea (I) with cyanoacetic acid (II) in hot acetic anhydride gives 6-amino-1,3-diethyluracil (III) which is nitrosated with NaNO2/HOAc in water to yield 6-amino-1,3-diethyl-5-nitrosouracil (IV). The reduction of (IV) with Na2S2O4 and K2CO3 in concentrated aqueous ammonia affords 5,6-diamino-1,3-diethyluracil (V), which is condensed with either 3-(3,4-dimethoxyphenyl)-2(E)-propenoyl chloride (VI) in EtOH/water or 3-(3,4-dimethoxyphenyl)-2(E)-propenoic acid (VII) and 3-[3-(diethylamino)propyl]-1-ethylcarbodiimide (EDAC) in dioxane/water to provide the corresponding amide (VIII). Cyclization of (VIII) by means of NaOH in the same solvent furnishes the xanthine derivative (IX), which is finally methylated with methyl iodide and K2CO3 in DMF.

Cyclization of N,N'-diethylurea (I) with cyanoacetic acid (II) in hot acetic anhydride gives 6-amino-1,3-diethyluracil (III) which is nitrosated with NaNO2/HOAc in water to yield 6-amino-1,3-diethyl-5-nitrosouracil (IV). The reduction of (IV) with Na2S2O4 and K2CO3 in concentrated aqueous ammonia affords 5,6-diamino-1,3-diethyluracil (V), which is condensed with either 3-(3,4-dimethoxyphenyl)-2(E)-propenoyl chloride (VI) in EtOH/water or 3-(3,4-dimethoxyphenyl)-2(E)-propenoic acid (VII) and 3-[3-(diethylamino)propyl]-1-ethylcarbodiimide (EDAC) in dioxane/water to provide the corresponding amide (VIII). Cyclization of (VIII) by means of NaOH in the same solvent furnishes the xanthine derivative (IX), which is finally methylated with methyl iodide and K2CO3 in DMF.