52944-50-0Relevant academic research and scientific papers
Hydroformylation and hydrocarbethoxylation of 1,2-dicarbethoxy-1,2,3,6-tetrahydropyridazine and 1,2-dicarbethoxy-1,2,3,4-tetrahydropyridazine
Menchi, G.,Paganelli, S.,Matteoli, U.,Scrivanti, A.,Botteghi, C.
, p. 229 - 235 (1993)
The unsaturated compounds 1,2-dicarbethoxy-1,2,3,6-tetrahydropyridazine 1 and 1,2-dicarbethoxy-1,2,3,4-tetrahydropyridazine 2 have been hydroformylated and hydrocarbethoxylated in the presence of some well known cobalt, rhodium, palladium and platinum catalysts.The hydroformylation reaction can be tuned by a suitable choice of the catalyst precursor and reaction conditions, thus allowing the synthesis with high selectivity of one of the two possible isomeric aldehydes.The carbonylation reaction is less synthetically useful, since it shows low activity andunsatisfactory chemo- and regio-selectivity.However, the ester 1,2,4-tricarbethoxyhexahydropyridazine 10 can be prepared in good yield from olefin 1 by using the complex as the catalyst precursor.
An ATR-FTIR study on the effect of molecular structural variations on the CO2 absorption characteristics of heterocyclic amines, part II
Robinson, Kelly,McCluskey, Adam,Attalla, Moetaz I.
experimental part, p. 2331 - 2341 (2012/10/07)
This paper reports on an ATR-FTIR spectroscopic investigation of the CO2 absorption characteristics of a series of heterocyclic diamines: hexahydropyrimidine (HHPY), 2-methyl and 2,2-dimethylhexahydropyrimidine (MHHPY and DMHHPY), hexahydropyridazine (HHPZ), piperazine (PZ) and 2,5- and 2,6-dimethylpiperazine (2,6-DMPZ and 2,5-DMPZ). By using in situ ATR-FTIR the structure-activity relationship of the reaction between heterocyclic diamines and CO2 is probed. PZ forms a hydrolysis-resistant carbamate derivative, while HHPY forms a more labile carbamate species with increased susceptibility to hydrolysis, particularly at higher CO2 loadings (>0.5 mol CO2/mol amine). HHPY exhibits similar reactivity toward CO2 to PZ, but with improved aqueous solubility. The α-methyl-substituted MHHPY favours HCO3- formation, but MHHPY exhibits comparable CO2 absorption capacity to conventional amines MEA and DEA. MHHPY show improved reactivity compared to the conventional α-methyl- substituted primary amine 2-amino-2-methyl-1-propanol. DMHHPY is representative of blended amine systems, and its reactivity highlights the advantages of such systems. HHPZ is relatively unreactive towards CO 2. The CO2 absorption capacity CA (mol CO 2/mol amine) and initial rates of absorption RIA (mol CO2/mol amine min-1) for each reactive diamine are determined: PZ: CA=0.92, RIA=0.045; 2,6-DMPZ: C A=0.86, RIA=0.025; 2,5-DMPZ: CA=0.88, R IA=0.018; HHPY: CA=0.85, RIA=0.032; MHHPY: CA=0.86, RIA=0.018; DMHHPY: CA=1.1, R IA=0.032; and HHPZ: no reaction. Calculations at the B3LYP/6-31+G* and MP2/6-31+G* calculations show that the substitution patterns of the heterocyclic diamines affect carbamate stability, which influences hydrolysis rates. Copyright
Process for producing hexahydropyridazine and hexahydropyridazine-1,2-dicarboxy derivative
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, (2008/06/13)
The present invention provides a process for producing a hexahydropyridazine-1,2-dicarboxy derivative represented by the general formula: STR1 wherein R1 and R2 represent each independently an alkyl group, by reacting a hydrazinedicarboxy derivative represented by the general formula: wherein R1 and R2 have the same meaning as mentioned above, with a dihalogenobutane represented by the general formula: wherein X1 and X2 represent each independently a halogen atom, in the presence of an alkali metal hydroxide, characterized in that the above reaction is effected in an aprotic polar solvent, and a process for producing a hexahydropyridazine, characterized by decarboxylating the thus obtained hexahydropyridazine-1,2-dicarboxy derivative (3) without isolation in the presence of an alkali metal hydroxide and a hydrogen-denoting compound.
Synthesis of (±)tetrahydromyricoidine
Song, Jiangao,Hesse, Manfred
, p. 6797 - 6804 (2007/10/02)
A total synthesis of the spermidine alkaloid (±)-tetrahydromyricoidine (6) was achieved by using two ring enlargement reactions. The difficulties experienced in the second ring enlargement step, a transamidation reaction with a medium ring sized lactam bearing two bulky groups are discussed. These were overcome by altering the reaction sequence and the transamidation reaction was successfully carried out by at first deprotection of the Boc function. spermidine alkaloids; (±)-tetrahydromyricoidine; ring enlargement.
