26934-29-2Relevant academic research and scientific papers
Ring size and substituent steric effects in cyclic ketene-N,O/S-acetal trifluoroacetylations
De Silva, Hondamuni I.,Song, Yingquan,Henry, William P.,Pittman Jr., Charles U.
supporting information; experimental part, p. 2965 - 2970 (2012/07/30)
Trifluoroacetylations of cyclic ketene-N,O/S-acetals exhibit a ring size effect. The five-membered rings 2,4,4-trimethyl-2-oxazoline, 2-methyl-2-oxazoline, and 2-methyl-2-thiazoline, each form cyclic ketene-N,O/S-acetal intermediates which then react with trifluoroacetic anhydride to give β-monotrifluoroacetylation products. Conversely, the six-membered ring 2-methyl-2-oxazine gives its β,β- bistrifluoroacetylation product. In situ-generated five-membered ring N-Me cyclic ketene-N,O-acetals, 3,4,4-trimethyl-2-methylene-oxazolidine, and 3-methyl-2-methylene-oxazolidine, and six-membered ring 3-methyl-2-methylene-1, 3-oxazinane were each β,β-bistrifluoroacetylated. However, 3-methyl-2-methylene-oxazolidine also afforded a γ-lactam by an iodide-catalyzed rearrangement of its β,β-bistrifluoroacetylated derivative. In situ-generated 3-methyl-2-methylene-thiazolidine gives both β-mono- and β,β-bistrifluoroacetylation products and no lactam, in contrast to its N,O-analog 3-methyl-2-methyleneoxazolidine.
Versatile synthesis of secondary 2-amino thiols and/or their disulfides via thiazolinium salts
Mercey, Guillaume,Lohier, Jean-Francois,Gaumont, Annie-Claude,Levillain, Jocelyne,Gulea, Mihaela
supporting information; experimental part, p. 4357 - 4364 (2011/02/24)
Commercially available β-amino alcohols have been transformed into various secondary β-amino thiols and/or their disulfides by using methyl dithioacetate as a source of sulfur. The transformation involves a thiazolinium salt as a versatile key intermediate, which enables easy modulation of the product structure by varying the substituents on the hetero-cycle and the N-alkylating agent.
Generation of cyclic ketene-N,X-acetals (X = O, S) from 2-alkyl-1,3-oxazolines and 2-alkyl-1,3-thiazolines. Reactions with acid chlorides, 1,3-diacid chlorides and N-(chlorocarbonyl) isocyanate
Zhou, Aihua,Pittman Jr., Charles U.
, p. 37 - 48 (2007/10/03)
2-Alkyl-1,3-oxazolines, 2-alkyl-1,3-thiazolines, and the corresponding cyclic ketene-N,X-acetals (X = O, S) derived from them were reacted with monoacid chlorides, diacid chlorides, triacid chlorides. A series of these carbon-carbon bond-forming reactions and cyclizations to both substituted 2,3-dihydrooxazolo[3,2-a]pyridine-5,7-diones and 2,3-dihydrothiazolo[3,2-a] pyridine-5,7-diones proceeded under mild reaction conditions. Cyclic ketene-N,X-acetal intermediates play important roles in all these reactions. Related cyclizations with N-(chlorocarbonyl) isocyanate formed substituted 2,3-dihydrooxazolo[3,2-c]pyrimidine-5,7-diones and 2,3-dihydrothiazolo[3,2-c] pyrimidine-5,7-diones. Georg Thieme Verlag Stuttgart.
Reactions of 2-methylthiazolines and N-methyl cyclic ketene-N,S-acetals with acid chlorides
Zhou, Aihua,Pittman, Charles U.
, p. 8899 - 8903 (2007/10/03)
Carbon-carbon bond formation occurs under mild conditions when 2-methylthiazolines react with acid chlorides to form N-acyl-β-keto cyclic ketene-N,S-acetals. N-Methyl cyclic ketene-N,S-acetals, generated from 2-methyl-thiazolines, can react further with acid chlorides to form N-methyl-β-keto cyclic ketene-N,S-acetals.
Research on radioprotective agents: Δ-2 Thiazolines and homologous derivatives
Robbe,Fernandez,Chapat,et al.
, p. 16 - 24 (2007/10/02)
Compounds derived from Δ-2 thiazoline, Δ-2 thiazolinium iodoalkylate and 4,5-dihydro-1,3 thiazine have been prepared and evaluated as potential antiradiation agents in mice. They generally have a low toxicity and significant radioprotective activity.
