Secondary amine-initiated three-component synthesis of 3,4-dihydropyrimidinones and thiones involving alkynes, aldehydes and thiourea/urea

• Jie-Ping Wan,
• Yunfang Lin,
• Kaikai Hu and
• Yunyun Liu

Beilstein J. Org. Chem. 2014, 10, 287–292, doi:10.3762/bjoc.10.25

• aldehydes, electron deficient alkynes and ureas/thioureas have been smoothly performed to yield a class of unprecedented 3,4-dihydropyrimidinones and thiones (DHPMs). The reactions are initiated by the key transformation of an enamine-type activation involving the addition of a secondary amine to an alkyne

Reaction of 2,2,4,4-tetrakis(trifluoromethyl)-1,3-dithiethane with N-vinyl compounds

• Viacheslav A. Petrov and
• Will Marshall

Beilstein J. Org. Chem. 2013, 9, 2615–2619, doi:10.3762/bjoc.9.295

• of thione 5 formation is not clear at this point. The formation of the corresponding thiones in the reaction of 1 with N-alkylimidazoles was found to be common in nature. Experimental 1H NMR and 19F NMR spectra were recorded on a Bruker DRX-500 (499.87 MHz) instrument by using CFCl3 or TMS as an

Synthesis of the reported structure of piperazirum using a nitro-Mannich reaction as the key stereochemical determining step

• James C. Anderson,
• Andreas S. Kalogirou,
• Michael J. Porter and
• Graham J. Tizzard

Beilstein J. Org. Chem. 2013, 9, 1737–1744, doi:10.3762/bjoc.9.200

• stereochemistry between the two protons, which confirmed the anti-relative stereochemistry of 21. The observed coupling constant between the same two protons was 8.2 Hz (averaged) and was similar to other imidazolidine-2-thiones we have prepared that have been corroborated by single crystal X-ray crystallography

A facile, rapid, one-pot regio/stereoselective synthesis of 2-iminothiazolidin-4-ones under solvent/scavenger-free conditions

• Murugan Sathishkumar,
• Sangaraiah Nagarajan,
• Poovan Shanmugavelan,
• Murugan Dinesh and
• Alagusundaram Ponnuswamy

Beilstein J. Org. Chem. 2013, 9, 689–697, doi:10.3762/bjoc.9.78

• -triazoles [25], 1,2,3-triazolylchalcones [26], and 1,2,3-triazolyldihydropyrimidine-2-thiones [27], we herein present a one-pot solvent/scavenger-free synthetic protocol for 2-iminothiazolidin-4-ones. This environmentally benign method avoids toxic organic solvents and acid scavengers, the details of which

Synthesis of 2,3-dihydronaphtho[2,3-d][1,3]thiazole-4,9-diones and 2,3-dihydroanthra[2,3-d][1,3]thiazole-4,11-diones and novel ring contraction and fusion reaction of 3H-spiro[1,3-thiazole-2,1'-cyclohexanes] into 2,3,4,5-tetrahydro-1H-carbazole-6,11-diones

• Lidia S. Konstantinova,
• Kirill A. Lysov,
• Ljudmila I. Souvorova and
• Oleg A. Rakitin

Beilstein J. Org. Chem. 2013, 9, 577–584, doi:10.3762/bjoc.9.62

• complex can convert N-substituted 2-methyl-1H-indoles to [1,2]dithiolo[4,3-b]indole-3(4H)-thiones [15]. A reaction of naphthoquinone 3a with a fivefold excess of complex 8 in chlorobenzene for 0.5 h at −20 °C with subsequent treatment with Et3N and heating at 100 °C for another 0.5 h, led to a blue solid

• then extended to other anthraquinone derivatives 4. Fused anthraquinonothiazole-2-thiones 10 were isolated in yields ranging from moderate to low together with chlorinated products 9 (with higher yields in most cases). To confirm the structure of anthraquinonothiazoles 10 we treated thiazole 2c with

• DABCO, attacks the less bulky methyl group giving thiazoles, which are subsequently transformed to thiazole-2-thiones 10 by the further action of S2Cl2 and Hünig’s base. Further study of the reaction between 2-[cyclohexyl(methyl)amino]naphthoquinone 1d and complex 8 in chlorobenzene allowed us to

New simple synthesis of ring-fused 4-alkyl-4H-3,1-benzothiazine-2-thiones: Direct formation from carbon disulfide and (E)-3-(2-aminoaryl)acrylates or (E)-3-(2-aminoaryl)acrylonitriles

• Qiuping Ding,
• Yuqing Lin,
• Guangni Ding,
• Fumin Liao,
• Xiaoyan Sang and
• Yi-Yuan Peng

Beilstein J. Org. Chem. 2013, 9, 460–466, doi:10.3762/bjoc.9.49

• their preparation have been reported in the literature [9][10][11][12][13][14][15]. 4-Alkyl-4H-3,1-benzothiazine-2-thiones are an important class of 4H-3,1-benzothiazine derivatives. Therefore, 4-alkyl-4H-3,1-benzothiazine-2-thione derivatives are also of potential biological importance. However, only a

Advances in synthetic approach to and antifungal activity of triazoles

• Kumari Shalini,
• Nitin Kumar,
• Sushma Drabu and
• Pramod Kumar Sharma

Beilstein J. Org. Chem. 2011, 7, 668–677, doi:10.3762/bjoc.7.79

• -benzyl]-4-aryl-1,2,4-triazole-3-thiones were synthesized by Ezabadi et al., and evaluated for in vitro antifungal activity against Aspergillus flavus, Aspergillus versicolor, Aspergillus ochraceus, Aspergillus niger, Trichoderma viride and Penicillium funiculosum. Of the compounds obtained, 5-[2-(N,N

Asymmetric synthesis of tertiary thiols and thioethers

• Jonathan Clayden and
• Paul MacLellan

Beilstein J. Org. Chem. 2011, 7, 582–595, doi:10.3762/bjoc.7.68

• of enone 46. Organocatalytic conjugate addition to nitroalkenes 49. Preparation of β-amino acid 54. Sulfur migration within oxazolidine-2-thiones 56. Preparation of thiols 62 by self-regeneration of stereocentres. Synthesis of (5R)-thiolactomycin. Preparation of tertiary thiols and thioethers via α

Redox-active tetrathiafulvalene and dithiolene compounds derived from allylic 1,4-diol rearrangement products of disubstituted 1,3-dithiole derivatives

• Filipe Vilela,
• Peter J. Skabara,
• Christopher R. Mason,
• Thomas D. J. Westgate,
• Asun Luquin,
• Simon J. Coles and
• Michael B. Hursthouse

Beilstein J. Org. Chem. 2010, 6, 1002–1014, doi:10.3762/bjoc.6.113

• the discovery of an unexpected rearrangement of 4,5-bis(2-arylhydroxymethyl)-1,3-dithiole-2-thiones (2) in the presence of acid catalysts [4]. As well as the expected dihydrofuran, formed by a nucleophilic ring-closing reaction, other compounds were also produced depending on the nature of the aryl

• (0.1 M), with a scan rate of 100 mV s−1. Acid-catalysed behaviour of 4,5-bis(2-arylhydroxymethyl)-1,3-dithiole-2-thiones 2. The proposed mechanism for the formation of 3. The proposed mechanism for the decomposition of 13 in the presence of perchloric acid. Reagents and conditions: (i) LDA (1 equiv

Zeolite catalyzed solvent- free one-pot synthesis of dihydropyrimidin- 2(1H)-ones – A practical synthesis of monastrol

• Mukund G. Kulkarni,
• Sanjay W. Chavhan,
• Mahadev P. Shinde,
• Dnyaneshwar D. Gaikwad,
• Ajit S. Borhade,
• Attrimuni P. Dhondge,
• Yunnus B. Shaikh,
• Vijay B. Ningdale,
• Mayur P. Desai and
• Deekshaputra R. Birhade

Beilstein J. Org. Chem. 2009, 5, No. 4, doi:10.3762/bjoc.5.4

• sensitive functional groups like the NO2, Cl, OH, OCH3 and conjugated double bonds affect neither the course nor the yield of the reaction. The scope of the reaction was further expanded when the reaction was carried out successfully using thiourea to provide the corresponding dihydropyrimidin-2(1H)-thiones

• (4m–4p). These thiones are also of much interest with regard to biological activity. One of the well-known examples of dihydropyrimidin-2-(1H)-thiones is the compound monastrol (4n), a potent inhibitor of kinesin Eg5 (Figure 1). We could achieve the synthesis of this compound in one step using 3