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A number of upper rim-functionalized calix[4]thiourea cyclohexanediamine derivatives have been designed, synthesized and used as catalysts for enantioselective Michael addition reactions between nitroolefins and acetylacetone. The optimal catalyst 2 with a mono-thiourea group exhibited good performance in the presence of water/toluene (v/v = 1:2). Under the optimal reaction conditions, high yields of up to 99% and moderate to good enantioselectivities up to 94% ee were achieved. Detailed experiments clearly showed that the upper rim-functionalized hydrophobic calixarene scaffold played an important role in cooperation with the catalytic center to the good reactivities and enantioselectivities.

A convenient synthesis of 4, 6-dihydro-2-methyl-pyrimidine can be obtained by cyclization reaction of acetamidine hydrochloride and diethyl malonate in the presence of sodium methoxide for a 91.2 % yield. 4, 6-Dihydro-2-methyl-5-nitropyrimidine can be achieved by nitration under the mixed acids of nitric acid, trichloroacetic acid and acetic acid in an 88.3 % yield and then the chlorination using phosphorus oxytrichloride can afford 4, 6-dichloro-2-methyl-5-nitropyrimidine with an 82.6 % yield.