Anticoccidial agents. 1. Synthesis and anticoccidial activity of 4-deoxypyridoxol and its esters

Abstract

Convenient methods for the syntheses of 4-deoxypyridoxol (2, R = CHs) and -methylpyridoxol (1) from pyridoxine were developed. as-0-Monoacyl-4-deoxypyridoxols were, in general, obtained by selective hydrolysis of 3,a5-0diacyl-4-deoxypyridoxols. 4-Deoxypyridoxol and its esters were found to exhibit anticoccidial activity against Eimeria acervulina.

Modification at the 2-Position of 4-Deoxypyridoxol and α4-Norpyridoxol

“…After removal of the catalyst, the filtrate was concentrated illto dryness to give a crystalline product, which was recrystallized from EtOH-EtzO to give a 2 -methyl-4-deoxypyridoxol HCI (10, 0.5 g), mp 174~ 17rc. NMR il~~I~: 1 …”

“…In the present paper, we describe the synthesis of the analogs of 4-deoxypyridoxol and a 4 -norpyridoxol in which the methyl group at position 2 is replaced by an ethyl, hydrogen, hydroxymethyl or methoxy group. 1 R=Me…”

“…Firstly a 2 -methyl-4-deoxypyridoxol (10) was prepared from 4-deoxypyridoxol (1, by the method 1 ) essentially identical with that applied to the synthesis of a 2 -methylpyridoxol: 4-deoxypyridoxol (1) was converted to the dibenzyl ether (3) with benzyl chloride and sodium hydride in dimethylformamide, which was subsequently oxidized with m-chloroperbenzoic acid in chloroform; rearrangement with acetic anhydride, hydrolysis with hydrochloric acid, and oxidation with manganese dioxide furnished the 2-formyl derivative (7). The Grignard reaction of the 2-formyl comt Studies on Anticoccidial Agents.…”

Synthesis of 4-Propenyl-α4-norpyridoxols through Claisen Rearrangement

“…IR )! :;-'~j~l cm- 1 (Xl) To a stirred solution of the alcohol (X, 0.70 g) in dry benzene (10 m!) was added dropwise SOCl z (0.7 mI).…”

“…The extract was washed with water, and dried and the solvent was evaporated to leave an oil, which was chromatographed over silica gel to yield 19.0 g of lIb as an oil. NMR o~~~ la: 1 …”