Synthesis of Some New Substituted Imidazo (1, 2-a) Pyridines and Their 2-One Derivatives

2, 3-diaminopyridine (11)(a tri-nitrogen nucleophile) undergoes regioselective cyclocondensation reaction with nitrilimines (2, 10) affording 8-aminoimidazo [1, 2-a] pyridines (12) and 8-aminoimidazo [1, 2-a] pyridine-2-ones (13), respectively. The structures of the new compounds (12, 13) were deduced from their IR, MS and NMR spectral data

Kedudukan dan peranan wanita dalam kebudayaan suku bangsa Minangkabau

Buku ini menggambarkan bagaimana Kedudukan dan Peranan Wanita pada suku bangsa Minangkabau, mulai dari mengurus anak, kadang-kadang membantu perekonomian Rumah Tangga, menyediakan persiapan untuk upacara sampai memelihara harta pusaka, karena Minangkabau mengenal Sistem Matrilin eal, di mana wanita berhak atas ·harta warisan. Meskipun kaum pria turut mengelola harta warisan tersebut, tetapi mereka tidak berhak untuk menjual atau menggadaikannya, karena harus seizin saudara-saudara wanitanya atau saudara perempuannya. Jadi wanita di Minangkabau sangat berperan dan se lalu dimintai pendapatnya, serta tidak pernah ditinggalkan pada waktu berunding. Di sini tampak bahwa kedudukan wanita di Minangkabau sejak dulu telah sejajar dengan pria, bahkan dalam banyak hal peranan mereka lebih besar daripada pria. Mereka mempunyai hak-hak dan memegang peranan dalam kehidupan masyarakat Minangkabau, terutama peranannya dalam keluarga besar dan di rumah Gadang

Substituted 1, 2-thiazetidine 1, 1-dioxides. Synthesis and properties of N-alkylated and N-acylated derivatives of 1, 2-thiazetidine-3-acetic acid 1, 1-dioxide

1,2-Thiazetidine-3-acetic acid 1,1-dioxide was N-alkylated using bromoacetates, and N-acylated using either acyl chlorides, protected amino acid fluorides, or N-protected amino acid NCA, which seemed to be the most universal method. Most of the obtained “β-sultam peptides” were sensitive against humidity, they hydrolyzed forming sulfonic acids, and reactions with amines resulted in sulfonamides. Reactions of N-acylated products showed that the sulfonyl group was faster attacked than the imide structure

Substituted 1, 2-thiazetidine 1, 1-dioxides. Synthesis of (RS)-and (S)-1, 2-thiazetidine-3-acetic acid 1, 1-dioxide and its reactions with amino acids and dipeptides

(RS)-2-tert-Butyldimethylsilyl-1,2-thiazetidine-3-acetic acid 1,1-dioxide prepared from (RS)-S-benzyl-β-homocysteine was condensed via DCC/NHS with various L-amino acid esters or dipeptide esters yielding N-silylated β-sultam peptides. A β-sultam active ester was isolated as an intermediate. Desilylation with TBAF in THF yielded stable N-unsubstituted products, and deprotection of the benzyl esters was achieved by catalytic hydrogenation. (S)-S-Benzyl-β-homocysteine was obtained by fractional crystallization of the brucine salt of the racemate and transformed into benzyl (S)-1,2-thiazetidine-3-acetate, which was on the other hand synthesized by an enantiospecific route from ω-benzyl Boc-L-aspartate. Some β-sultam peptides were prepared from the (S)-enantiomer, and finally some β-sultam peptides containing D-Ala units were obtained

4-[2-(4-Fluoro­phen­yl)furan-3-yl]pyridine

In the crystal structure of the title compound, C15H10FNO, the furan ring makes dihedral angles of 40.04 (11) and 25.71 (11)° with the pyridine and 4-fluoro­phenyl rings, respectively. The pyridine ring makes a dihedral angle of 49.51 (10)° with the 4-fluoro­phenyl ring. Non-conventional C—H⋯F and C—H⋯N hydrogen bonds are effective in the stabilization of the crystal structure

4-[2-(4-Fluoro­phen­yl)-1H-pyrrol-3-yl]pyridine

In the crystal structure of the title compound, C15H11FN2, the pyrrole ring makes dihedral angles of 33.19 (9) and 36.33 (10)° with the pyridine and 4-fluoro­phenyl rings, respectively. The pyridine ring makes a dihedral angle of 46.59 (9)° with the 4-fluoro­phenyl ring. In the crystal structure, an N—H⋯N hydrogen bond joins the mol­ecules into chains

Crystal structures of pure 3-(4-bromo-2-chlorophenyl)-1-(pyridin-4-yl) benzo [4, 5] imidazo [1, 2-d][1, 2, 4] triazin-4 (3H)-one and contaminated with 3-(4-bromophenyl)-1 …

The side product of the cyclocondensation reaction between ethyl benzimidazole-2-carboxylate and the nitrile imine of the corresponding hydrazonyl chloride, C20H11BrClN5O, crystallized in two crystal forms. Form (1) is a co-crystal of the target compound (without any chlorine substituent) and a side product containing a Cl atom in position 2 of the bromophenyl group, C20H12BrN5O·0.143C20H11BrClN5O. (2) contains the pure side product. The slightly different conformation of the ring systems leads to a different packing of (1) and (2), but both crystal structures are dominated by π–π interactions