Musante, Carlo published the artcileSome salts and derivatives of 3,5-diiodo-4(1H)-pyridone-1-acetic acid, Synthetic Route of 101-29-1, the publication is Gazzetta Chimica Italiana (1948), 873-80, database is CAplus.
The work was prompted by the growing importance of derivatives of 3,5-diiodo-4(1H)-pyridone-1-acetic acid (I) in radiol. HC:CI.CO.CI:CH.NH (II) was purified by dissolving in a min. of N NaOH, heating at 100°, and repptg. by a current of CO2. ClCH2CONEt2 (III) (4.5 g.), added slowly to 10.5 g. pure II in N NaOH, allowed to stand several hrs. (frequent agitation), and the precipitate purified by EtOH, yields 8.6 g. (62%) N,N-diethyl-3,5-diiodo-4(1H)-pyridone-1-acetamide, m. 231°. Pure HC:CBr.CO.CBr:CH.NH (IV) was prepared by allowing 5.56 g. pyridone in 40 cc. AcOH and 9.3 g. Br to stand 5 h., diluting with water, dissolving the precipitate in N NaOH, and repptg. by CO2. III (4 g.), added slowly to 5 g. IV, allowed to stand several hrs., and the precipitate purified by EtOH, yields approx. 5 g. 3,5-dibromo-N,N-diethyl-4(1H)-pyridoneacetamide, m. 224-5°. II (4.4 g.) in 20 cc. N NaOH agitated with 2.5 cc. Me2SO4, heated to 100°, allowed to stand 30 min., and the precipitate purified by water, yields 4 g. HC:CI.CO.CI:CH.NMe (V). Aqueous KMnO4 (400 cc. of 1%) added slowly to aqueous V (1 g. in 180 cc.), and the mixture steam-distilled, yields CHI3; the residue, filtered and concentrated, yields a solution containing an iodide (indicated by acidification with H2SO4 and addition of CHCl3 and Cl water). In contrast to this, II is not oxidized by KMnO4 under the same conditions. However, boiling II and aqueous KMnO4 several hrs. yield a little iodide and (CO2H)2. I (2 g.) and 15 cc. SOCl2, refluxed 2 h. (the solution turns red, then colorless), distilled, and the residue taken up in Et2O, dissolved in aqueous NaOH, and reprecipitated by CO2, yield II. Salts of I were prepared from alc. I and aqueous solutions of salts of the metals concerned. They are probably of normal electrovalent structure, of low solubility in water and organic solvents, and melt at high temperatures, with decomposition Salts: Ag, from AgNO3 (100% yield), m. 297°, turns brown in light; Pb, from acidic Pb(OAc)2, m. approx. 300°; Cd, from Cd(OAc)2, lustrous, m. 286°; mercuric, from Hg(OAc)2, m. 253°; cupric, from Cu(OAc)2, blue-green, m. 257°; Zn, from Zn(OAc)2, m. 285°; Co, from Co(NO3)2 buffered by NaOAc, rose color, turns brown at 200°, violet at 240°, blackish at 270°, and m. 295°; Ni, from Ni(OAc)2, light green (no m.p. given); ferric, from FeCl3, ocher-yellow, turns almost black 270°, m. 290°; La, from boiling aqueous LaCl3, turns brown approx. 270°, decompose around 300°, solubility in water 3.33 × 10-4 g.-mol./l. at 20°; Pr, from PrCl3, turns brown around 280-5°, decompose around 300°; Nd, from boiling aqueous (PhS)3Nd, begins to decompose 285°, decompose completely 300°; Sm, from boiling aqueous (PhS)3Sm, decompose around 300°; Gd, from boiling aqueous (PhSO3)3Gd, decompose around 300°, solubility in water 3.33 × 10-4 g.-mol./l. at 20°. Pb 3,5-dibromo-4(1H)-pyridone-1-acetate, (C7H4O3NBr2)2Pb, from Pb(OAc)2 and HC:CBr.CO.CBr:CH.NCH2CO2H, no m.p. given.
Gazzetta Chimica Italiana published new progress about 101-29-1. 101-29-1 belongs to iodides-buliding-blocks, auxiliary class Pyridine,Iodide,Carboxylic acid,Ketone, name is 2-(3,5-Diiodo-4-oxopyridin-1(4H)-yl)acetic acid, and the molecular formula is C7H5I2NO3, Synthetic Route of 101-29-1.
Referemce:
https://en.wikipedia.org/wiki/Iodide,
Iodide – an overview | ScienceDirect Topics – ScienceDirect.com