92210-61-2

Usage

InChI:InChI=1/C10H9NO4/c1-14-9-2-3-10-7(5-9)4-8(6-15-10)11(12)13/h2-5H,6H2,1H3

Upstream product

• 672-13-9 2-hydroxy-5-methoxybenzaldehyde 
• 3638-64-0 1-nitroethylene 
• 625-48-9 2-nitro-1-ethanol 

Downstream Products

• 1370549-72-6 (6aS,13cR)-9-benzyl-2-methoxy-6a-nitro-6,6a,7,8,9,13c-hexahydrochromeno[3,4-c]carbazole 
• 119755-63-4 6-methoxy-3-amino-3,4-dihydro-2H-1-benzopyran 

Relevant academic research and scientific papers

Asymmetric Synthesis of Functionalized Tricyclic Chromanes via an Organocatalytic Triple Domino Reaction

A highly stereoselective triple domino reaction for the synthesis of functionalized tricyclic chromane scaffolds has been developed. A secondary amine-catalyzed domino Michael/Michael/aldol condensation reaction between aliphatic aldehydes, nitro-chromene

1,4-addition of TMSCCl3 to nitroalkenes: Efficient reaction conditions and mechanistic understanding

Improved synthetic conditions allow preparation of TMSCCl3 in good yield (70 %) and excellent purity. Compounds of the type NBu4X [X=Ph3SiF2 (TBAT), F (tetrabutylammonium fluoride, TBAF), OAc, Cl and Br] act as catalytic promoters for 1,4-additions to a range of cyclic and acyclic nitroalkenes, in THF at 0-25 °C, typically in moderate to excellent yields (37-95 %). TBAT is the most effective promoter and bromide the least effective. Multinuclear NMR studies (1H, 19F, 13C and 29Si) under anaerobic conditions indicate that addition of TMSCCl3 to TBAT (both 0.13 M) at -20 °C, in the absence of nitroalkene, leads immediately to mixtures of Me3SiF, Ph3SiF and NBu4CCl3. The latter is stable to at least 0 °C and does not add nitroalkene from -20 to 0 °C, even after extended periods. Nitroalkene, in the presence of TMSCCl3 (both 0.13 M at -20 °C), when treated with TBAT, leads to immediate formation of the 1,4-addition product, suggesting the reaction proceeds via a transient [Me 3Si(alkene)CCl3] species, in which (alkene) indicates an Si O coordinated nitroalkene. The anaerobic catalytic chain is propagated through the kinetic nitronate anion resulting from 1,4 CCl3 - addition to the nitroalkene. This is demonstrated by the fact that isolated NBu4[CH2=NO2] is an efficient promoter. Use of H2C=CH(CH2)2CH=CHNO 2 in air affords radical-derived bicyclic products arising from aerobic oxidation. Understanding TMSCCl3: The synthesis and reactivity of TMSCCl3 has been investigated. The mechanism of 1,4-CCl3 addition to nitroalkenes begins with nitroalkene coordination, followed by the attack of an external fluoride ion, and does not involve the formation of NBu4[Me3SiFCCl3] (see figure).

Efficient conjugate addition of carbonyl compounds to 3-nitro-2H-chromenes in the presence of bases

The conjugate addition of aldehydes and ketones to 3-nitro-2H-chromenes under basic conditions has been explored. A series of inorganic and organic bases were examined. Proline combined with NaOAc was found to act as an efficient catalyst for the reaction

Substituted 3-amido and 3-amidoalkylbenzopyran derivatives: Synthesis and pharmacological activity as melatonin ligands

A novel series of melatonin analogues based on the benzopyran nucleus is described. These compounds are prepared in several steps from substituted 2-hydroxybenzaldehydes. Some of these derivatives competitively inhibit 2-[125I]iodomelatonin binding to chicken brain and ovine pars tuberalis membranes although with reduced affinity compared with melatonin.

New Direct Synthesis of 3-Nitro-2H-chromenes Using Nitroethylene

The treatment of substituted 2-hydroxybenzaldehydes by nitroethylene, prealably prepared or generated in situ within the reaction, in the presence of di-n-butylamine gave 3-nitro-2H-chromenes in fair to excellent yields.