AN ULTRASOUND MEDIATED GREEN SYNTHESIS OF 2-PYRAZOLINE DERIVATIVES

2021 ◽  
pp. 36-39
Author(s):  
Shrivastava Birendra ◽  
Upasna Upasna ◽  
Arora Satish Chander
Keyword(s):  
Acetic Acid ◽  
Green Synthesis ◽  
19Th Century ◽  
Heterocyclic Compounds ◽  
Unsaturated Aldehydes ◽  
Aldehydes And Ketones ◽  
The 19Th Century

Pyrazolines are prominent nitrogen-containing heterocyclic compounds and therefore, various procedures have been worked out for their synthesis. After the pioneering work of Fischer and Knoevenagel in the 19th century, the reaction of α, β-unsaturated aldehydes and ketones with phenylhydrazine in acetic acid by reuxing became one of the most popular methods for the preparation of 2-pyrazolines. Aseries of substituted 2- pyrazolines was synthesized by ultrasound irradiated method to nd out cleaner/ greener approaches.

Grammatical Descriptions in Manchu Grammar Books from the Qing Dynasty

2019 ◽  
Vol 41 (1) ◽  
pp. 39-55
Author(s):  
Takashi Takekoshi
Keyword(s):  
19Th Century ◽  
Qing Dynasty ◽  
The Qing Dynasty ◽  
Chinese Scholars ◽  
High Degree ◽  
The 19Th Century

In this paper, we analyse features of the grammatical descriptions in Manchu grammar books from the Qing Dynasty. Manchu grammar books exemplify how Chinese scholars gave Chinese names to grammatical concepts in Manchu such as case, conjugation, and derivation which exist in agglutinating languages but not in isolating languages. A thorough examination reveals that Chinese scholarly understanding of Manchu grammar at the time had attained a high degree of sophistication. We conclude that the reason they did not apply modern grammatical concepts until the end of the 19th century was not a lack of ability but because the object of their grammatical descriptions was Chinese, a typical isolating language.

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