Isonicotinic acid methyl ester

The des-ethyl derivative 251 of Flavopereirine was prepared similarly starting from 2-chloro isonicotinic acid methyl ester 250 (Scheme 81). The resulting hydrochloride was converted into the pseudo-cross-conjugated... 

Picolinic acid methyl ester, L Nicotinic acid methyl ester, L Isonicotinic acid methyl ester, L... 

A thioamide of isonicotinic acid has also shown tuberculostatic activity in the clinic. The additional substitution on the pyridine ring precludes its preparation from simple starting materials. Reaction of ethyl methyl ketone with ethyl oxalate leads to the ester-diketone, 12 (shown as its enol). Condensation of this with cyanoacetamide gives the substituted pyridone, 13, which contains both the ethyl and carboxyl groups in the desired position. The nitrile group is then excised by means of decarboxylative hydrolysis. Treatment of the pyridone (14) with phosphorus oxychloride converts that compound (after exposure to ethanol to take the acid chloride to the ester) to the chloro-pyridine, 15. The halogen is then removed by catalytic reduction (16). The ester at the 4 position is converted to the desired functionality by successive conversion to the amide (17), dehydration to the nitrile (18), and finally addition of hydrogen sulfide. There is thus obtained ethionamide (19)... 

C H6N20 1453-82-3) see Cefsulodin isonicotinic acid 2-(2-carboxyethyl)hydrazide methyl ester (CinllnN, ), 90872-10-9) see Nialamide isonicotinoyl chloride... 

Isonicotinic acid hydrazide (isoniazid 275), a drug used in treating tuberculosis269, has been 1 -labelled264 by introduction of a [nC]cyano group at the 2-position of the pyridine ring of l-methoxy-4-methoxcarbonyl pyridinium methyl sulphate and subsequent treatment of the 1 -labelled methyl ester 276 with hydrazine hydrate. The reaction has been carried out on a solid support (silica gel) to yield methyl 2[11C]cyano-isonicotinate in 32.4+12% (EOB) yield. 275 was obtained in 10% (EOB), radiochemical... 

Isoniazid, U5P. Isonicotinic acid hydru/.ide. isonicoti-nyl hydrazide. or INH (Nydrazid) (K curs as a nearly culoi-less crystalline solid that is very soluble in water. It is prepared by reacting the methyl ester of isonicotinic acid iih hydrazine. 

Green RW and Tong HK, The constitution of the pyridine monocarboxylic acids in their isoelectric forms, JACS, 78,4896-4900 (1956). Used a glass electrode standardized with phflialate solution (pH = 4.00) and the Guntelberg equation to correct for I. Estimated the microconstants from spectrophotometric data on the acid and its methyl ester pJ A, 2.11 pK, 3.13 pJ o 4.77 pKo, 3.75 where the subscripts represent the following equilibria A, diprotonated to zwitterion B, diprotonated to neutral C, zwitterion to fully deprotonated D, neutral to fully deprotonated. Also reported the corresponding data for picolinic and isonicotinic acids. 

---