96232-69-8Relevant academic research and scientific papers
Regioselective and efficient halogenation of 4,5-unsubstituted alkyl 3-hydroxypyrrole/3-hydroxythiophene-2-yl-carboxylates
Castillo-Aguilera, Omar,Depreux, Patrick,Halby, Ludovic,Azaroual, Nathalie,Arimondo, Paola B.,Goossens, Laurence
, p. 2537 - 2541 (2017/06/13)
Substituted heterocycles, such as pyrrole and thiophene, are commonly found in the field of pharmaceutical and material sciences. Here we studied the reactivity of 4,5-unsubstituted alkyl 3-hydroxypyrrol-2-yl-carboxylates and 4,5-unsubstituted alkyl 3-hydroxythiophen-2-yl-carboxylates in different halogenation conditions, due to their interest as building blocks in the synthesis of bioactive compounds and materials. We describe herein the regioselective monohalogenation of 3-hydroxypyrroles and 3-hydroxythiophenes in mild conditions with common halogenation agents. The selectivity of the halogenation was studied. Optimized one-step reaction conditions were found for monobromination and monochlorination. Finally, we observed that bromination with N-bromosuccinimide (NBS) took place at the C4 position of the heterocycle, while chlorination with SO2Cl2 led to C5-halogenated derivatives.
Organic compounds and their use as pharmaceuticals
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, (2008/06/13)
Compounds of the following formula have pharmacutical properties: STR1 in which R1 and R2 independently are hydrogen, halo, nitro, amino, C2-5 acylamino, C1-4 alkyl, C1-4 alkoxy, C1-4 alkylthio, C1-4 alkylsulphonyl, N-substituted heterocyclyl, optionally substituted phenyl, optionally substituted phenylthio, optionally substituted phenylsulphonyl or optionally substituted phenylsulphonamido, or R1 and R2 together form a C3-5 alkylene bridge, R3 is C1-4 alkyl or C2-4 alkenyl, and X is (i) --(CH2)n N(R4)2 where each R4 independently is C1-4 alkyl, C2-4 alkenyl or optionally substituted C6 H5 CH2 --, and n is 1, 2 or 3, or (ii) a 5- to 8-membered alicyclic group containing one or two nitrogen atoms and directly attached to the amido nitrogen or attached by a C1-3 alkylene chain; and salts thereof.
