4.6- Diaryl-3,4-dihydropyrimidin-2 -thiones

The following syntheses all proceeded regioselectively 4,6-diaryl-3,4-dihydropyrimidine-2-thiones with 3-bromopropionic acid in a Ac20/AcOH system <2001MI407, 2000IJH49>, or with acrylonitrile in pyridine followed by hydrolysis <1996IJB915> resulted 6,8-diaryl-2,3-dihydro+//,6//-pyrirnido[2,l+][l,3]thiazin-4-ones in good yield 4-phenyl-5-carbethoxy-3,4-dihydropyrimidine-2-thiones with benzylidenemalonitrile in a NaOAc/AcOH system... 

Chalcones are good precursors for the synthesis of various heterocycles such as pyrimidines. Thus, their treatment with urea supported on neutral alumina under dry conditions and MWI produced 4,6-diaryl-3,4-dihydropyrimidin-2(l//)-ones 514, while on treatment with thiourea produced the corresponding 4,6-diaryl-3,4-dihyd-ropyrimidine-2(l//)-thiones 515 (Scheme 100). Shorter times (2-6 min instead of 4-5 h) and better yields (69-85% instead of 59-72%) of products were achieved compared to conventional heating (99SC3237). 

Golovach NM, Sukach VA, Vovk MV (2012) Synthesis of (5 )-(-)-l,4-Diaryl-6-methyl-4-trifluoromethyl-3,4-dihydropyrimidine-2(l/7)-thiones. Russ J Org Chem 48 430-433... 

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See also in sourсe #XX -- [ ]

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