- Preparation method of 3-hydroxy-4-methoxy-2-nitrobenzoic acid
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The invention discloses a preparation method of 3-hydroxy-4-methoxy-2-nitrobenzoic acid, and belongs to the field of synthesis of medical intermediates. The preparation method comprises the followingsteps: starting from 3-alkoxy-4-acetoxybenzaldehyde (1), carrying out a nitration reaction process to obtain an intermediate (2), removing acetyl from the intermediate (2) to obtain an intermediate (3), methylating to obtain an intermediate (4), oxidizing the intermediate (4) to obtain an intermediate (5), deprotecting the intermediate (5), and recrystallizing to remove the isomer, thereby obtaining the 3-hydroxy-4-methoxy-2-nitrobenzoic acid (6). The method is simple, convenient and stable to operate, high in yield, environment-friendly, low in production cost and suitable for industrial large-scale production, and products in all steps are easy to separate.
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Paragraph 0050-0052; 0057-0059; 0064-0066
(2020/07/12)
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- Asymmetric, stereocontrolled total synthesis of paraherquamide A
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The first total synthesis of paraherquamide A, a potent anthelmintic agent isolated from various Penicillium sp. with promising activity against drug-resistant intestinal parasites, is reported. Key steps in this asymmetric, stereocontrolled total synthesis include a new enantioselective synthesis of (α-alkylated-β-hydroxyproline derivatives to access the substituted proline nucleus and a highly diastereoselective intramolecular S N2′ cyclization to generate the core bicyclo[2.2.2]diazaoctane ring system.
- Williams, Robert M.,Cao, Jianhua,Tsujishima, Hidekazu,Cox, Rhona J.
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p. 12172 - 12178
(2007/10/03)
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