2-Methyl-2-thiopseudourea → 2-Methylthio-thiopyranopyrimidine

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Reaction Steps

According to the above reaction scheme, ethyl 3-oxotetrahydrothiopyran-2-carboxylate is reacted with S-methylisothiourea in the presence of a basic catalyst such as potassium hydroxide, sodium hydroxide, potassium carbonate, sodium carbonate, sodium hydride, sodium methoxide, sodium ethoxide and the like, in a solvent such as methanol, ethanol, isopropyl alcohol, N,N-dimethylformamide to produce a 2-methylthio-thiopyranopyrimidine compound (V), and the resulting compound (V) is then heated under acidic conditions, preferably in a mixture of acetic acid and water to produce a 2,4-dihydroxythiopyranopyrimidine compound (VI). Subsequently, the resulting 2,4-dihydroxy compound (VI) is reacted with phosphorus oxychloride in the absence or presence of a tertiary amine such as N,N-dimethylaniline, N,N-diethylaniline and the like to obtain the starting material of the formula (III).

Provenance & Evidence