25314-91-4

Upstream product

• 4637-24-5 N,N-dimethyl-formamide dimethyl acetal 
• 274-40-8 indolizine 
• 108-24-7 acetic anhydride 
• 75-36-5 acetyl chloride 
• 75487-74-0 2-methyl-1-(2-oxo-propyl)-pyridinium; bromide 
• 36805-97-7 N,N-dimethylformamide di-tert-butyl acetal 

Relevant academic research and scientific papers

Controlling chemoselectivity-application of DMF di-t-butyl acetal in the regioselective synthesis of 3-monosubstituted indolizines

Among a number of DMF dialkyl acetals investigated for the regioselective synthesis of 3-acylindolizines, the di-t-butyl acetal, via its iminium intermediate readily formed in situ, provides the highest chemoselectivity for the intermolecular cyclization of picolinium salts. DMF di-t-butyl acetal was applied to the syntheses of a variety of 3-acylated indolizines including alkyl, aryl, and heteroaryl substituents.

Plladium-catalyzed arylation and heteroarylation of indolizines

A highly effective protocol for palladium-catalyzed selective arylation and heteroarylation of indolizines at C-3 has been developed. Mechanistic studies unambiguously support an electrophilic substitution pathway for this transformation.

SYNTHESIS OF INDOLIZINES

Disclosed are methods of preparing substituted indolizines represented by the following formula: comprising reacting a substrate represented by the following formula: with either the cyclization reagent of the following formula: or, a reagent prepared by reacting the compound represented the formula below with an alkylating agent: The variables in the above formulas are defined herein.

Indolizines 4. The synthesis of new 3-vinylindolizines.

New 3-vinylindolizines have been synthesized by two methods.The first strategy calls for the Wittig olefination of 3-acylindolizines with methylenetriphenylphosphorane or methoxymethylenetriphenylphosphorane.The best yields are obtained when the ylid is formed at room temperature and the condensation in refluxing THF.The required 3-acylindolizines were obtained by direct acylation of indolizines or by 1,3-dipolar cyclo-additions to acylmethylpyridinium ylids.The following 3-isopropenylindolizines were made with good yields: unsubstituted (18, 85percent), 2-methyl (10, 98percent), 2-C6H5 (17, 95percent), 1-COOMe (20, 98percent), 1-COOMe-2-C6H5 (22, 91 percent), 1,2-di-COOMe (24, 58percent).Also synthesized are the following 3-α-styrylindolizines: 2-C6H5 (19, 99percent), 1-COOMe (21, 93percent), 1-COOMe-2-C6H5 (23, 87percent), 1,2-diCOOMe (25, 66percent). 3-(α-Methyl-β-methoxyvinyl)indolizines E (26, 40percent) and Z (27, 40percent) were also obtained.The second strategy involves the 1,3-dipolar cyclo-addition of dipolarophiles to allylpyridinium ylids.The following new 3-vinylindolizines have been synthesized: 1-carbomethoxy-3-vinylindolizine (30, 21percent), 1,2-dicarbomethoxy-3-vinylindolizine (31, 16percent), 1-carbomethoxy-3-β-styrylindolizine (33, 43percent), 3-β-styrylindolizine (34, 17percent), 1-carbomethoxy-3-(β-carbomethoxy)vinylindolizine 38 (31percent).

A new approach for the synthesis of fused pyrroles. The synthesis of acyl substituted pyrrolo[1,2-x]azines

N-Acetonyl- and N-phenacyl quaternary salts of α-methyl substituted heterocycles 16, 17, 21, 23 and 26 were converted with DMFDMA into the corresponding 3-acylpyrrolo[1,2-a]pyridine 18, 7-benzoylpyrrolo[1,2- c]pyrimidine 22, and 6-benzoylpyrrolo[1,2-a]pyrazine derivatives 24 and 27. A concurrent reaction produced methyl and phenyl substituted pyrrolo[1,2- x]azines 19, 20, 25 and 28.