89080-61-5

Upstream product

• 99-61-6 3-nitro-benzaldehyde 
• 105-45-3 acetoacetic acid methyl ester 
• 39562-17-9 methyl 2-(3-nitrophenylmethylene)acetoacetate 

Downstream Products

• 173597-69-8 1,4-Dihydro-1-(methoxycarbonyl-methyl)-2,6-dimethyl-4-(3-nitrophenyl)pyridin-3,5-dicarbonsaeuredimethylester 
• 173597-67-6 3,5-Bis(methoxycarbonyl)-1,4-dihydro-2,6-dimethyl-4-(3-nitrophenyl)-1-pyridyl-essigsaeure 
• 89080-37-5 1-hydroxy-2,6-dimethyl-4-(3-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylic acid dimethyl ester 

Relevant academic research and scientific papers

A mild and convenient one-pot synthesis of 4-aryl-n-oh-hantzsch esters

A general methodology to prepare a series of 4-Aryl-N-OH Hantzsch esters was developed. The key factor is to control the first-step of Michael addition at 0 °C. The method was practical to produce symmetrical and unsymmetric N-OH-Hantzsch esters in moderate yield. This class of compounds might have use in medicinal and material science.

Synthesis and reactions of 3,5-bis(methoxycarbonyl)-1,4-dihydro-2,6-dimethyl-4-nitrophenyl-1-pyri dyl acetic acids

Hantzsch synthesis with methyl acetoacetate, 2- or 3-nitrobenzaldehyde and glycine as amine component yields the N-alkylated 1,4-dihydropyridines (DHP) 2. 2b and the esters 3b, c thereof are also obtained from the reaction of the tetracarbonyl compound 1b with glycine or the methylester hydrochloride and pyridine, respectively. The acids 2 cyclize with pyridiniumbromide perbromide (PBPB) to form the oxazolo[3,2-a]pyridines 4-6, while the monobromo and bis(monobromo) substitution products 7 and 8 are acquired from the esters 3. Heating 7b in acetic acid yields the biphenylglycine ester 9. 7b cyclizes with hydroxylamine to form the pyrrolo[3,4-b]pyridine 10. With potassium carbonate the pyrido[2,1-c][1,4]oxazine 11 is obtained, whose structure is proven by an independent way of synthesis following the acetate 12 and its product of hydrolysis 13 as intermediates. The pyrrolidine 14, the thioacetate 15 and the chloride 16 are achieved by reaction of further nucleophiles with 7b. 8b, treated with pyridine, yields the bispyridinium dibromide 17. Heating the DHP 3b with trifluoroacetic anhydride leads to the pyrano[4,3-b]pyridine 18. The stability of the DHP is investigated by anodic oxidation using difference pulse polarography.