NISCAIR Online Periodicals Repository Collection: IJC-B Vol.51B(08) [August 2012]

Green synthesis of novel isoxazoline derivatives using N-methyl-α-chloro nitrone and their antibacterial activities

Sun, 29 Jul 2012 22:58:59 GMT

Title: Green synthesis of novel isoxazoline derivatives using N-methyl-α-chloro nitrone and their antibacterial activities

Authors: Chakraborty, Bhaskar; Sharma, Prawin Kumar; Samanta, Amalesh

Abstract: Microwave assisted 1,3-dipolar cycloaddition reaction of N-methyl-α-chloro nitrone with various alkynes as dipolarophile have been studied and found to afford diastereomeric novel isoxazoline derivatives with high selectivity. All the synthesized compounds have been screened for their antibacterial activity and are found to exihibit significant activity.

Page(s): 1180-1185

Ultrasound and microwave assisted rapid and sustainable route to synthesis of benzothiazine derivatives

Sun, 29 Jul 2012 22:58:59 GMT

Title: Ultrasound and microwave assisted rapid and sustainable route to synthesis of benzothiazine derivatives

Authors: Dabholkar, Vijay V; avande, Rahul P G

Abstract: Ultrasound and microwave assisted synthesis of 2-Meldrum-2H,4H-2-carbonyl methyl-3-oxo-1,4-benzothiazine 10, 2-dimi-done-2H,4H-2-carbonyl methyl-3-oxo-1,4-benzothiazine 11, 2H,4H-2-amino-[3-methyl pyrazol-5-one-1-yl]-carbonyl methyl-3-oxo-1,4-benzothiazine 12,2H,4H-2-amino-[3,5-dmethyl pyrazol-1-yl]-carbonyl methyl-3-oxo-1,4-benzothiazine 13 and 2H, 4H-2-amino-[3-phenyl, 5-methyl pyrazol-1-yl]-carbonyl methyl-3-oxo-1,4-benzothiazine 14 from 2-aminobenzenethiol and 1,3 diketo compounds containing active methylene group have been carried out. All the synthesized compounds have been investigated for their antibacterial activities. The result indicate that the compounds show convincing activities against Gram-positive bacteria (Bacillus subtilis and Streptococcus lactis) when compared with standard drug (ampicillin trihydrate). These compounds have been also synthesized by conventional method and their structures have been elucidated on the basis of spectral analyses and chemical reactions.

Page(s): 1173-1179

Zinc chloride promoted efficient and facile BOC protection of amines

Sun, 29 Jul 2012 22:58:59 GMT

Title: Zinc chloride promoted efficient and facile BOC protection of amines

Authors: Arifuddin, M; Lakshmikant, N; Rajasekar, N; Shinde, D B

Abstract: Amines are efficiently protected as their BOC derivatives under mild reaction conditions when reacted with BOC anhydride in presence of ZnCl₂. The present method is applicable to a variety of amines including aliphatic, aromatic as well as heteroaromatic amines. This protocol appears to be competitive and in some cases superior to previously reported procedures that work under basic conditions.

Page(s): 1168-1172

Iodine catalysed aza-Michael addition of carbamates to chalcones

Sun, 29 Jul 2012 22:58:59 GMT

Title: Iodine catalysed aza-Michael addition of carbamates to chalcones

Authors: Deuri, Sanjib; Kataki, Dolly; Phukan, Prodeep

Abstract: Iodine has been found to catalyze the aza-Michael reaction of chalcones with weaker nucleophile carbamates. Although iodine alone can promote the reaction, addition of TMSCl enhances the yield of the product. A variety of chalcones have been reacted with benzyl carbamate to produce b-amino-carbonyl compounds in high yield.

Page(s): 1163-1167