NISCAIR Online Periodicals Repository Collection: IJC-B Vol.50B(12) December 2011]

Direct conversion of (R)-epichlorohydrin to (S)-3-aminopropane-1,2-diol: An important chiral C-3 building block

Title: Direct conversion of (R)-epichlorohydrin to (S)-3-aminopropane-1,2-diol: An important chiral C-3 building block

Authors: Bhavani, Ch; Babu, K Chandra; Naresh, E; Sridhar, P; Madhusudhan, G

Abstract: A new and effective method for the preparation of optically active (S)-3-amino-1,2-propanediol 1 has been established starting from (R)-epichlorohydrin 2. The synthetic approach involves the reaction of (R)-epichlorohydrin 2 with acetone catalyzed by boron trifluoride etherate (BF₃·OEt₂) to give the (R)-4-(chloromethyl)-2,2-dimethyl-1,3-dioxolane, 5. Replacing the chloro group in (R)-5 with amino group by azidation followed by reduction gives ((S)-2,2-dimethyl-1,3-dioxolan-4-yl)methanamine 7. Acetal deprotection of the obtained (S)-7 with MeOH.HCl gives (S)-3-aminopropane-1,2-diol·HCl.

Page(s): 1807-1811

Synthesis and antimicrobial activity of novel spiro-isoxazolyl oxazolidin-4-one-[5,5¹]-1,2,4-oxadiazolines and thiazolidin-4-one-[5,5¹]-1,2,4-oxadiazolines

Title: Synthesis and antimicrobial activity of novel spiro-isoxazolyl oxazolidin-4-one-[5,5¹]-1,2,4-oxadiazolines and thiazolidin-4-one-[5,5¹]-1,2,4-oxadiazolines

Authors: Rajanarendar, E; Reddy, A Siva Rami; Reddy, K Govardhan; Raju, S

Abstract: The synthesis of novel isoxazolyl 1,6-dioxa-2,4,9-triazaspiro[5,5¹]-non-2-ene-8-ones 4 and isoxazolyl 1-oxa-6-thia-2,4,9-triazaspiro[5,5¹]-non-2-ene-8-ones 6 analogs is described. Reaction of N-1-(3,5-dimethyl-4-isoxazolyl)-2-chloroacetamide 2 with arylisocyanates yields 3-(3,5-dimethyl-4-isoxazolyl)-2-arylimino-1,3-oxazolan-4-ones 3. Cycloaddition of 3 with benzonitrile oxides furnishes novel spiro isoxazolyl oxazolidin-4-one[5,5¹]-1,2,4-oxadiazolines 4. Reaction of 2 with arylisothiocyanates affords 3-(3,5-dimethyl-4-isoxazolyl)-2-arylimino-1,3-thiazolan-4ones 5. Cycloaddition of 5 with benzonitrile oxides yields novel spiro isoxazolyl thiazolidin-4-one[5,5¹]-1,2,4-oxadiazolines 6. All the new products have been characterized by elemental analyses, IR, ¹H NMR and mass spectral studies. Compounds 4 and 6 have been screened for their antimicrobial activity.

Page(s): 1800-1806

Microwave assisted synthesis of some novel pyrazole substituted benzimidazoles and evaluation of their biological activities

Title: Microwave assisted synthesis of some novel pyrazole substituted benzimidazoles and evaluation of their biological activities

Authors: Kalirajan, R; Rathore, Leela; Jubie, S; Gowramma, B; Gomathy, S; Sankar, S

Abstract: A series of novel and significant compounds containing pyrazole substituted benzimidazoles 4a-h and 5a-h have been synthesized from o-phenylenediamine under microwave irradiation. The structures of the newly synthesized compounds have been confirmed on the basis of elemental analysis and spectral data. Some of the synthesized compounds 4b, 4h, 5d, 5f exhibit significant antibacterial activity. The compounds 5b, 5f exhibit good antifungal activity. Compounds 5a and 5b have shown good anticancer activity and the compound 4a exhibits significant anti tubercular activity.

Page(s): 1794-1799

Molecular and crystal structure of 8-acetoxy goniofufurone from Goniothalamus wyanaadensis, Bedd.

Title: Molecular and crystal structure of 8-acetoxy goniofufurone from Goniothalamus wyanaadensis, Bedd.

Authors: Ajithabai, M D; Rameshkumar, B; Jayakumar, G; Varma, Luxmi; Nair, Mangalam S

Abstract: Lactones, sterol, acetogenin and alkaloid are isolated for the first time from Goniothalamus wyanaadensis, Annonaceae. Structures are elucidated by spectral studies. Single crystal X-ray diffraction data of 8-acetoxy goniofufurone is reported.

Page(s): 1786-1793

NISCAIR Online Periodicals Repository Collection: IJC-B Vol.50B(12) December 2011]

Direct conversion of (R)-epichlorohydrin to (S)-3-aminopropane-1,2-diol: An important chiral C-3 building block

Synthesis and antimicrobial activity of novel spiro-isoxazolyl oxazolidin-4-one-[5,51]-1,2,4-oxadiazolines and thiazolidin-4-one-[5,51]-1,2,4-oxadiazolines

Microwave assisted synthesis of some novel pyrazole substituted benzimidazoles and evaluation of their biological activities

Molecular and crystal structure of 8-acetoxy goniofufurone from Goniothalamus wyanaadensis, Bedd.

Synthesis and antimicrobial activity of novel spiro-isoxazolyl oxazolidin-4-one-[5,5¹]-1,2,4-oxadiazolines and thiazolidin-4-one-[5,5¹]-1,2,4-oxadiazolines