排序方式: 共有11条查询结果,搜索用时 19 毫秒
1.
Sankareswaran Srimurugan Paulsamy Suresh Thirukkallam Kanthadai Varadarajan 《合成通讯》2013,43(15):2483-2490
A facile method for the synthesis of (2R,3R)‐1,4‐dimethoxy‐1,1,4,4‐tetrasubstituted‐2,3‐butanediols involving oxidative cleavage of benzylidene acetal as a key step is described. These sterically hindered diols unusually formed cyclic sulfites as the major product under methanesulfonylation reaction conditions. 相似文献
2.
In this study, an improved process for the synthesis of etorphine and dihydroetorphine from codeine with an overall yield of 2.7% and 1.5% respectively is described. The structure of 19‐propylthevinol 7 was verfied by X‐ray structure analysis. This result is promising for synthesizing various morphine‐based drugs. 相似文献
3.
Sankareswaran Srimurugan Thirukkallam Kanthadai Varadarajan 《Tetrahedron letters》2005,46(18):3151-3155
Microwave irradiation of various dialdehydes and chiral diamines afforded chiral macrocyclic imines in moderate to good yields. Linked dialdehydes predominantly form [2+2] macrocycles whereas dialdehydes without linkers yield [3+3] macrocycles. This is the first report of template-free synthesis of calixsalen-type macrocycles formed in shorter reaction times under microwave conditions. In all the reactions, the salts of chiral diamines were used in contrast to the free diamines normally employed. 相似文献
4.
Paulsamy Suresh Sankareswaran Srimurugan Ravindra T. Dere R. Venkat Ragavan Vadiraj Suphala Gopinath 《Tetrahedron: Asymmetry》2013,24(11):669-676
A series of new chiral binol based [1+1] macrocyclic Schiff bases have been synthesized in high yields in short reaction times via cyclo-condensation of dialdehydes with long tethers and chiral diamines. Macrocyclic Mn(salen) complexes containing N2O2 salen units incorporated with spacers of increased tether lengths were synthesized and characterized. The newly synthesized catalyst system was successfully employed for the enantioselective epoxidation of unfunctionalized olefins with high yields and good enantioselectivity. 相似文献
5.
Madhava Rao Mannam Srimurugan S. Pramod Kumar R. S. Prasad K 《Journal of heterocyclic chemistry》2019,56(8):2179-2191
A new series of 1‐(5‐(benzylsulfinyl)‐3‐methyl‐1,3,4‐thiadiazol‐2(3H)‐ylidene)‐thiourea/urea derivatives ( 1a – j ) were designed and synthesized. For the first time, (i) a new process was developed for N‐methylation of 1,3,4‐thiadiazole moiety using dimethyl carbonate an environmentally benign reagent in presence of N,N,N′,N′‐tetramethylethylenediamine and (ii) the sulfide was selectively oxidized to sulfoxide in higher yield by using chlorine (g) in aqueous acetic acid media under mild reaction condition. The synthesized compounds ( 1a – j ) were investigated for their antimicrobial activities. The tested compounds ( 1a – j ) were exhibited moderate to excellent antibacterial activities against both Gram‐positive and Gram‐negative bacterial strains. The same compounds exhibited good antifungal activities against selected fungal strains. Particularly, the compounds 1b , 1d , 1h , and 1i were proved to be promising leads exhibiting both antibacterial and antifungal activities compared with standard drugs, ciprofloxacin, and fluconazole. The presence of 1,3,4‐thiadiazole moiety has a significant role in the display of antimicrobial activity. In addition, the presence of both sulfinyl and thiourea or urea functionalities has enhanced the activity as per obtained antimicrobial activity data. 相似文献
6.
Srimurugan S Viswanathan B Varadarajan TK Varghese B 《Organic & biomolecular chemistry》2006,4(16):3044-3047
Efficient synthesis of chiral [2 + 2] macrocyclic tetraimines which display calixarene-like crystal structures has been described, with short reaction times under microwave irradiation. 相似文献
7.
Sankareswaran Srimurugan Paulsamy Suresh Hari N. Pati 《Journal of inclusion phenomena and macrocyclic chemistry》2007,58(3-4):383-388
A novel double thicalix[4]arene possessing two amide sites was prepared. The binding behavior with Ag+ has been examined by 1H NMR titration experiment. The association constants K
ass of the amide sites are quite similar (K
ass = 2.10 × 104 M−1 and K
ass = 2.00 × 104 M−1), suggesting that the two amide sites work independently. 相似文献
8.
Srimurugan S Suresh P Babu B Hiriyanna SG Pati HN 《Chemical & pharmaceutical bulletin》2008,56(3):383-384
Tritylated tetrazole of 2a underwent unusual detritylation under basic reaction condition during the synthesis of methyl ether of olmesartan medoxomil 1. The unusual detritylation was found to be a common feature in the case of all tetrazole containing Sartan molecules (3-7). 相似文献
9.
Sankareswaran Srimurugan Chi-Ju Su Hun-Chi Shu Kaliyappan Murugan Chinpiao Chen 《Monatshefte für Chemie / Chemical Monthly》2012,14(2):171-174
Abstract
This work describes a convenient and improved process for the synthesis of desomorphine from codeine. The proposed method affords the highly pure opiate without the aid of chromatographic purification, and provides a simple route for the synthesis of [2H3] deuterium-labeled desomorphine. 相似文献10.
Silicomolybdic acid that is supported on silica gel (50 wt %) efficiently catalyzes the high-yielding Hosomi-Sakurai allylation of carbonyl compounds by allyltrimethylsilane in the presence of benzyl alcohol. The reaction rates of inactive substrates and the yields were greatly increased when preformed acetals were used as substrates. 相似文献