The Reactions of 6-(Hydroxymethyl)-2,2-dimethyl-1-azaspiro[4.4]nonanes with Methanesulfonyl Chloride or PPh3-CBr4

Activation of a hydroxyl group towards nucleophilic substitution via reaction with methanesulfonyl chloride or PPh3-CBr4 system is a commonly used pathway to various functional derivatives. The reactions of (5R(S),6R(S))-1-X-6-(hydroxymethyl)-2,2-dimethyl- 1-azaspiro[4.4]nonanes 1a–d (Х = O·; H; OBn, OBz) with MsCl/NR3 or PPh3-CBr4 were studied. Depending on substituent X, the reaction afforded hexahydro-1H,6H-cyclopenta[c]pyrrolo[1,2-b]isoxazole (2) (for X = O), a mixture of 2 and octahydrocyclopenta[c]azepines (4–6) (for X = OBn, OBz), or perhydro-cyclopenta[2,3]azeto[1,2-a]pyrrol (3) (for X = H) derivatives. Alkylation of the latter with MeI with subsequent Hofmann elimination afforded 2,3,3-trimethyl-1,2,3,4,5,7,8,8a-octahydrocyclopenta[c]azepine with 56% yield.

NbCl5-Mg Reagent System in Regio- and Stereoselective Synthesis of (2Z)-Alkenylamines and (3Z)-Alkenylols from Substituted 2-Alkynylamines and 3-Alkynylols

The reduction of N,N-disubstituted 2-alkynylamines and substituted 3-alkynylols using the NbCl5–Mg reagent system affords the corresponding dideuterated (2Z)-alkenylamine and (3Z)-alkenylol derivatives in high yields in a regio- and stereoselective manner through the deuterolysis (or hydrolysis). The reaction of substituted propargylamines and homopropargylic alcohols with the in situ generated low-valent niobium complex (based on the reaction of NbCl5 with magnesium metal) is an efficient tool for the synthesis of allylamines and homoallylic alcohols bearing a 1,2-disubstituted double bond. It was found that the well-known approach for the reduction of alkynes based on the use of the TaCl5-Mg reagent system does not work for 2-alkynylamines and 3-alkynylols. Thus, this article reveals a difference in the behavior of two reagent systems—NbCl5-Mg and TaCl5-Mg, in relation to oxygen- and nitrogen-containing alkynes. A regio- and stereoselective method was developed for the synthesis of nitrogen-containing E-β-chlorovinyl sulfides based on the reaction of 2-alkynylamines with three equivalents of methanesulfonyl chloride in the presence of stoichiometric amounts of niobium(V) chloride and magnesium metal in toluene.

Efficient Synthesis of Sulfinate Esters and Sulfinamides via Activated­ Esters of p-Toluenesulfinic Acid

Sulfinate esters were prepared by the process of activating p-toluenesulfinic acid with either cyanuric chloride, methanesulfonyl chloride, or 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDC-HCl). Activation of p-toluenesulfinic acid with cyanuric chloride led to the formation of sulfinate esters that were accompanied by the formation of the corresponding sulfones. The use of methanesulfonyl chloride for activation via methanesulfonic p-toluenesulfinic anhydride afforded mixtures of sulfinate esters and methanesulfonates. The use of the carbodiimide EDC proved to yield the best results with the highly selective formation of the target sulfinate esters. The use of trimethylacetic p-toluenesulfinic anhydride or cyanuric chloride to achieve the synthesis of sulfinamides proved to be ineffective due to poor chemoselectivity of the nucleophilic attack on the activated p-toluenesulfinic acid anhydride. Ultimately, the use of EDC-HCl to form the sulfinamides proved to be the best pathway for synthesis.

A one-pot multistep cyclization yielding thiadiazoloimidazole derivatives

A versatile synthetic procedure is described to prepare the benzimidazole-fused 1,2,4-thiadiazoles 2a–c via a methanesulfonyl chloride initiated multistep cyclization involving the intramolecular reaction of an in-situ generated carbodiimide with a thiourea unit. The structure of the intricate heterocycle 2a was confirmed by single-crystal X-ray analysis and its mechanism of formation supported by DFT computations.

Synthesis of a Cholesterylated Compound Containing Carboxyl Functional with PEG2000 Chain for Hepatic Targeting Liposome Ligand

A carboxyl functional cholesterylated compound for hepatic targeting liposome ligand T1 was synthesized. Cholesterol as starting material, after esterification with p-toluenesulfonyl chloride to get cholesterol tosylate M4, then etherification with tetraethylene glycol to get hydroxyl functional M3, M3 react react with methanesulfonyl chloride to get M2, M2 was elongated by reaction with PEG2000 to get M1 and M1 react with succine anhydride get T1. The target compounds afford cholesterylated hepatic targeting liposome ligands.

Orthoamide und Iminiumsalze, LXXXV [1]. Die Synthese von starken Formylierungsmitteln im präparativen Großmaßstab: N,N,N',N'- Tetraformylhydrazin und Formyl-aalen [Tris(diformylamino)methan] / Orthoamides and Iminium Salts LXXXV [1]. The Synthesis of Strong Formylating Reagents on a Large Preparative Scale: N;N;N';N'-Tetraformylhydrazine and Formyl-aalen [Tris(diformylamino)methane]

N;N;N';N'-Tetraformylhydrazine (3) can be pepared in good yields by heating of N;N'-diformylhydrazine (5) with N;N-diformylacetamide (6). The reaction of methanesulfonyl chloride with sodium diformamide (10) in a molar ratio of 2 : 5 in acetonitrile affords tris(diformylamino)methane (formyl-aalen, 2). Both reactions were used to prepare 3 and 2 in large quantities (ca. 200 to 400 g). A mechanism is proposed for the formation of 2 from methanesulfonyl chloride and 10.