thiourea and isothiocyanic-acid

In this work, a one-pot, telescopic approach is described for the combinatorial library of thiazolidine-2-imines. The synthetic manipulation proceeds smoothly via the reaction of 2-aminopyridine/pyrazine/pyrimidine with substituted isothiocyanates followed by base catalyzed ring closure with 1,2-dibromoethane to obtain thiazolidine-2-imines with broad substrate scope and high functional group tolerance. The synthetic strategy merges well with the thiourea formation followed by base catalyzed ring closure reaction for the thiazolidine-2-imine synthesis in a more modular and straightforward approach. The synthetic procedure reported herein represents a cleaner route toward thiazolidine-2-imines as compared to traditional methodologies. Moreover, the biological significance of combinatorially synthesized thiazolidin-2-imines has been investigated for their use as possible inhibitors for acetyl cholinesterase through molecular docking studies.

Topics: Acetylcholinesterase; Aminopyridines; Anticonvulsants; Antineoplastic Agents; Antitubercular Agents; Catalysis; Cholinesterase Inhibitors; Ethylene Dibromide; Humans; Imines; Isothiocyanates; Microwaves; Pyrazines; Pyrimidines; Small Molecule Libraries; Structure-Activity Relationship; Thiazolidines; Thiourea

Base-controlled regioselective synthesis of 2-imino thiazolines and 2-thioxoimidazolin-4-ones was achieved to use a one-pot reaction between chiral amino esters, isothiocyanates, and α-bromoketones/alkyl halides. This three-component coupling reaction in acetonitrile provides 2-imino thiazolines, whereas the formation of 2-thioxoimidazolin-4-ones was observed under basic conditions at ambient temperature. The corresponding products were obtained in good to excellent yield with broad substrate scope. Isolation of thiourea and thiohydantoin intermediates disclosed the course of the reaction mechanism.

Topics: Esters; Imidazolidines; Imines; Isothiocyanates; Ketones; Molecular Structure; Oxidation-Reduction; Stereoisomerism; Thiazoles; Thiohydantoins; Thiourea

Methods for the site-specific modification of proteins are useful for introducing biological probes into proteins and engineering proteins with novel activities. Herein, we genetically encode a novel noncanonical amino acid (ncAA) that contains an aryl isothiocyanate group which can form stable thiourea crosslinks with amines under mild conditions. We show that this ncAA (pNCSF) allows the selective conjugation of proteins to amine-containing molecular probes through formation of a thiourea bridge. pNCSF was also used to replace a native salt bridge in myoglobin with an intramolecular crosslink to a proximal Lys residue, leading to increased thermal stability. Finally, we show that pNCSF can form stable intermolecular crosslinks between two interacting proteins.

Topics: Amines; Amino Acids; Isothiocyanates; Molecular Structure; Myoglobin; Thiourea

An efficient one-pot, three-component synthesis of 2-imino-1,3-thiazolidines and 2-imino-1,3-thiazolines using ionic liquid-tethered 2-aminobenzimidazoles was reported. The protocol includes reaction of ionic liquid attached 2-aminobenzimidazoles with isothiocyanates to afford isothioureas, followed by its base induced inter and intramolecular nucleophilic displacement reactions with 1,2-dichloroethane (EDC) which results in thiazolidine ring formation. In the next to the last step, the ionic liquid support was removed by methanolysis to deliver 2-imino-1,3-thiazolidines, which were sequentially oxidized with manganese(III) triacetate to yield 2-imino-1,3-thiazolines. The salient feature of this method is the use of 1,2-dichloroethane as a synthetic equivalent for α-haloketone to avoid the use of toxic halogenating reagents.

Topics: Benzimidazoles; Ethylene Dichlorides; Imines; Ionic Liquids; Isothiocyanates; Molecular Structure; Thiazoles; Thiourea

Monitoring of mechanochemical thiocarbamoylation by in situ Raman spectroscopy revealed the formation of aryl N-thiocarbamoylbenzotriazoles, reactive intermediates deemed unisolable in solution. The first-time isolation and structural characterization of these elusive molecules demonstrates the ability of mechanochemistry to access otherwise unobtainable intermediates and offers a new range of masked isothiocyanate reagents.

Topics: Crystallography, X-Ray; Indicators and Reagents; Isothiocyanates; Models, Molecular; Spectrum Analysis, Raman; Thiourea; Triazoles

Isothiocyanates form adducts with a multitude of biomolecules, and these adducts need analytical methods. Likewise, analytical methods for hydrophilic isothiocyanates are needed. We considered reaction with ammonia to form thiourea derivatives. The hydrophilic, glycosylated isothiocyanate moringin, 4-(α-L-rhamnopyranosyloxy)benzyl isothiocyanate, was efficiently derivatized to the thiourea derivative by incubation with ammonia. The hydrophobic benzyl isothiocyanate was also efficiently derivatized to the thiourea derivative. The thiourea group provided a UV absorbing chromophore, and the derivatives showed expectable sodium and hydrogen adducts in ion trap mass spectrometry and were suitable for liquid chromatography analysis. Reactive dithiocarbamate adducts constitute the major type of reactive ITC adduct expected in biological matrices. Incubation of a model dithiocarbamate with ammonia likewise resulted in conversion to the corresponding thiourea derivative, suggesting that a variety of matrix-bound reactive isothiocyanate adducts can be determined using this strategy. As an example of the application of the method, recovery of moringin and benzyl isothiocyanate applied to cabbage leaf discs was studied in simulated insect feeding assays. The majority of moringin was recovered as native isothiocyanate, but a major part of benzyl isothiocyanate was converted to reactive adducts.

Topics: Chromatography, High Pressure Liquid; Chromatography, Liquid; Gas Chromatography-Mass Spectrometry; Glycosylation; Isothiocyanates; Molecular Structure; Tandem Mass Spectrometry; Thiocarbamates; Thiourea

Some new benzenesulfonylthiourea derivatives substituted with phthalazones (2a-q) were synthesized by refluxing the appropriate 4-aryl-1-oxophthalazin-2(1H)yl benzenesulfonamides with isothiocyanate in dry acetone over anhydrous K₂CO₃. All the synthesized compounds were characterized on the basis of IR, (1)H NMR, MS data and elemental analysis. These synthesized compounds (2a-q) at the dose of 20 mg/kg were tested for antihyperglycemic activity in the glucose-fed hyperglycemic normal rat model and among these compounds 2f and 2m showed modest antihyperglycemic activity.

Topics: Animals; Benzenesulfonates; Blood Glucose; Drug Design; Female; Glucose; Hyperglycemia; Hypoglycemic Agents; Isothiocyanates; Male; Phthalazines; Rats; Rats, Wistar; Structure-Activity Relationship; Thiourea

A Boranil fluorophore bearing a nitro-phenyl group has been selectively reduced to its anilino form and then successfully converted to amide, imine, urea, and thiourea derivatives which are fluorescent dyes. Its isolated isothiocyanate intermediate derivative was used in a model labeling experiment with Bovine Serum Albumin (BSA). The purified labeled-BSA exhibits strong luminescence (Φ(f) = 47%) in a phosphate buffer at pH = 7.4.

Topics: Boron Compounds; Fluorescent Dyes; Hydrogen-Ion Concentration; Isothiocyanates; Molecular Structure; Serum Albumin, Bovine; Thiourea; Urea

Synthesis and anti-melanoma activity of various naphthalimide analogs, rationally modified by introducing isothiocyanate (ITC) and thiourea (TU) functionalities, found in well-known anti-cancer agents, is described. The structure-activity relationship comparison of the novel agents in inhibiting cancer cell growth was evaluated in various melanoma cell lines. Both ITC and TU analogs effectively inhibited cell viability and induced apoptosis in various human melanoma cells. Nitro substitution and increase in alkyl chain length, in general, enhanced the apoptotic activity of ITC derivatives. All the new compounds were well tolerated when injected intraperitoneal (i.p.) in mice at effective doses at which both the ITC and TU derivatives inhibited melanoma tumor growth in mice following i.p. xenograft. The nitro substituted naphthalimide-ITC derivative 3d was found to be the most effective in inducing apoptosis, and in inhibiting melanoma cell and tumor growth.

Topics: Animals; Annexin A5; Antineoplastic Agents; Apoptosis; Cell Line, Tumor; Cell Proliferation; Cell Survival; Flow Cytometry; Humans; Hydrophobic and Hydrophilic Interactions; Injections, Intraperitoneal; Isothiocyanates; Melanoma; Mice; Mice, Nude; Naphthalimides; Neoplasm Transplantation; Skin Neoplasms; Structure-Activity Relationship; Thiourea

A traceless solid supported protocol for the synthesis of 2-aminobenzothiazoles is described, employing resin-bound acyl-isothiocyanate and a series of anilines. Cyclization of the resulting N-acyl, N'-phenyl-thioureas generates the 2-aminobenzothiazole scaffold, which can be further elaborated prior to hydrazine-mediated cleavage of the final products from the carboxy-polystyrene resin. A small, focused library of 2-aminobenzothiazoles was prepared.

Topics: Aniline Compounds; Benzothiazoles; Crystallography, X-Ray; Cyclization; Hydrazines; Isothiocyanates; Molecular Conformation; Thiourea

A new class of C-glycosyl amino acids displaying a thiourea segment as a linker has been designed and synthesized by addition of peracetylated glycosylmethyl isothiocyanates to an amine-functionalized amino acid (N(alpha)-Fmoc-beta-amino-l-alanine). Three pairs of compounds with alpha- and beta-galacto, alpha- and beta-gluco, and alpha- and beta-manno configuration have been prepared with yields ranging between 70 and 75%. The orthogonal set of protective groups (O-acetyl in the carbohydrate moiety and N-Fmoc in the amino acid residue) makes these compounds suitable substrates for the co-translational modification of natural peptides. The couplings of model hydroxy-free and perbenzylated glycosylmethyl isothiocyanates with the above N(alpha)-Fmoc-beta-amino-l-alanine and the N(alpha)-Boc-protected analogue have been carried out as well, thus broadening the scope of the coupling reaction. Nevertheless, there are limitations of this isothiocyanate-amine coupling in complex systems, and these are briefly discussed.

Topics: Alanine; Amines; Amino Acids; Carbohydrates; Combinatorial Chemistry Techniques; Isothiocyanates; Protein Modification, Translational; Stereoisomerism; Structure-Activity Relationship; Thiourea