Cecilia Polo

Synthesis of 1-Arylthiocarbonyl-4-isopropylamino-2,5-dihydro-1H-imidazole-2-thiones, a Novel Class of Imidazole Derivatives

The reaction between N-isopropylisocyanoacetamide and arylsulfenyl thiocyanates provides a useful route to 1-arylthiocarbonyl-4-isopropylamino-2,5-dihydro-1H-imidazole-2-thiones, a novel class of imidazole derivatives, whose structure was determined by X-ray analysis

One pot synthesis of 1,2,3-benzodithiazol-6-ones

Abstract The reaction of p -benzoquinone-4-oximes with disulfur dichloride affords the red 6 H -1,2,3-benzodithiazol-6-ones. Some ring chlorination occurs, but 2,6-substituents are retained in the products except for a tert -butyl group, which is, exceptionally, replaced by chlorine. 1,4-Naphthoquinone 4-oxime and 1,2-naphthoquinone 2-oxime similarly give the red 4-chloro-5 H -naphtho[1,2- d ][1,2,3]dithiazol-5-one and the blue 9-chloro-4 H -naphtho[2,3- d ][1,2,3]dithiazol-4-one respectively. A unified set of mechanisms is proposed for all of the reactions.

A facile synthesis of 1-aryl-2-artylthio-1H-imidazoles

The reaction between the hitherto unknown 2,2-diethoxy-1-isocyanoethane with sulfenyl chlorides and arylamines afforded isothioureas which were cyclized to give the title compounds

Synthesis of 2,4-Diarylthio-5-N-alkyl-N-phenylaminooxazoles. A Novel Class of Oxazole Derivatives

The reaction between N-alkylisocyanoacetanilides, arylsulfenyl chlorides and NEt 3 afforded 2,4-diarylthio-5-N-phenylaminooxazoles, a hitherto unknown class of oxazole derivatives

A short synthesis of potential juvenoids based on the isoxazole chemistry

3,4,5-Trisubstituted isoxazoles (1) and (4) afforded, after chromic oxidation and borohydride reduction, (±)-3-methyl-6-(3-methyl-5-phenylisoxazol-4-yl)-6-hydroxyhexanoic acid (2) or (±)-1-(3-methyl-5-phenylisoxazol-4-yl)-3,4-dihydro-1H-2-benzopyran-3-one (5) which were reduced to (±)-(Z/E)-3-methyl-7-benzoyl-8-oxonon-6-enoic acid (3) and (E)-2-(2-[2-benzoyl-3-oxobut-1-enyl]phenyl)acetic acid (6) with molybdenum hexacarbonyl. Lactone (5) afforded a single E-diasteroisomer of acid (6). Catalytic hydrogenation of 5 afforded selectively isoxazole (7) which was reduced with molybdenum hexacarbonyl to 2-(2-[2-benzoyl-3-oxobutyl]phenyl)acetic acid (8). Structures of products are related with those of some juvenoids

One-pot synthesis and chemistry of bis[1,2]dithiolopyrroles

Hunig’s base and S 2 Cl 2 give the fused 1,4-thiazines 1 and (in the presence of formic acid) 2 and 3, each of which readily extrudes sulfur, selectively and quantitatively, to give the fused pyrroles 4, 5 and 6 respectively; at higher temperatures Hunig’s base and S 2 Cl 2 can be converted into the pyrroles in one pot, and the cycloadducts 8 and 10 are thus readily available in two steps.

Regioselectivity in the 3,5-dialkylation of 3,5-dimethyl-4-(methylcyclo-hexen-1-yl)isoxazole

3,5-Dimethyl-4-(4-methylcyclohexen-1-yl)isoxazole reacts with β-methallyl chloride and either lithium isopropylcyclohexylamide or n-buthyl-lithium in THF to afford the three alkylation products II, III, IV, in yields controled by the ratio of isoxazole:base:halide