In general, if the atoms that make up the ring contain heteroatoms, such rings become heterocycles, and organic compounds containing heterocycles are called heterocyclic compounds. An article called Derivatives of pyrrylazobenzenearsonic acids, published in 1950, which mentions a compound: 2199-44-2, Name is Ethyl 3,5-Dimethyl-2-pyrrolecarboxylate, Molecular C9H13NO2, Computed Properties of C9H13NO2.
cf. C.A. 45, 9526a. The synthesis is essentially the same as previously described. 2,4-Dimethyl-3,5-carbethoxypyrrole (I) was prepared by the method of Knorr. I was saponified in 10% KOEt, and converted to 2,4-dimethyl-3-carbethoxy-5-pyrrolecarboxylic acid (II) by the method of Küster, et al. (C.A. 16, 3895). Decarboxylation of II by dry distillation gave 2,4-dimethyl-3-carbethoxypyrrole (III). I was also treated with concentrated H2SO4 by the method of Fischer and Walach (C.A. 20, 1620) to give 2,4-dimethyl-5-carbethoxy-3-pyrrolecarboxylic acid, which was decarboxylated by heating at atm. pressure to 2,4-dimethyl-5-carbethoxypyrrole (IV). Attempts to couple diazotized 4, 3-H2N(O2N)C6H3AsO3H2 and III were not successful; a resinous product, which could not be purified, was obtained, and III was isolated from the reaction mixture Attempts to couple a salt of diazotized 3,4-H2N(HO)C6H3AsO3H2 (V) with IV were also unsuccessful. p-H2NC6H4AsO3H2 (4.34 g.) in 50 cc. H2O containing 1.63 cc. concentrated H2SO4 was diazotized with 20 cc. N NaNO2 at 0-5° and the product filtered into 3.34 g. III in 200 cc. absolute EtOH. 4-(3-Carbethoxy-2,4-dimethyl-5-pyrrylazo)benzenearsonic acid (VI) precipitated as an orange-yellow powder. VI was filtered, rinsed with water, dissolved in aqueous NaOH, and the solution clarified with active C; acidification with dilute HCl gave 4.3 g. VI, orange-yellow microcrystals, decompose 210°, slightly soluble in water, somewhat more soluble in EtOH, nearly insoluble in C6H6 and ether, and soluble in dioxane; crystallization from dioxane gave well-formed needles. VI was precipitated from alk. solution with dilute acids. VI was stable in air under light. V (4.66 g.) in 70 cc. H2O containing 5.8 cc. concentrated H2SO4 was diazotized as above and the product filtered into 3.34 g. III in 200 cc. absolute EtOH. 2-(3-Carbethoxy-2,4-dimethyl-5-pyrrylazo)-1-phenol-4-arsonic acid (VII) precipitated, and addnl. amounts of VII were obtained on diluting with H2O. VII was then dissolved in N NaOH, the solution clarified with active C, added to 0.1 N HCl with constant stirring, and the precipitate was filtered, washed with H2O, dried, and recrystallized twice from dioxane to yield 7.2 g. VII, yellow needles, decompose 160°. VII was stable in air under light. (p-H2NC6H4)2As(:O)OH (1.46 g.) in 30 cc. H2O containing 3.7 cc. concentrated HCl was diazotized as above with 10 cc. N NaNO2 and the solution added dropwise at 5° or lower to 1.67 g. III in 70 cc. EtOH containing 5 g. NaOAc, previously dissolved in a small volume of H2O, to yield di-Et 5, 5′-[arsinobis(p-phenyleneazo)]bis[2,4-dimethyl-3-pyrrolecarboxylate] (VIII). VIII was filtered, washed with cold H2O, dried in vacuo, and recrystallized from dioxane and then from ether to yield 1 g. VIII, dark orange microcrystals, m. 151° (decomposition). VIII was soluble in EtOH, dioxane, and CHCl3. p-H2NC6H4AsO3H2 (2.17 g.) in 25 cc. H2O containing 0.81 cc. concentrated H2SO4 was diazotized with 10 cc. N NaNO2 and the product filtered into 1.67 g. IV in 200 cc. absolute EtOH; when the solution was clear 15 g. NaOAc in a small amount of H2O was added with cooling, and, after 1 hr., 4 l. H2O was added to precipitate 4-(5-carbethoxy-2,4-dimethyl-3-pyrrylazo)benzenearsonic acid (IX), yellow-orange powder. IX was twice dissolved in alkali and reprecipitated by dilute HCl, washed with water, and dried in vacuo to yield 1.2 g. IX, darkens 100°, m. 185° (decomposition), IX was soluble in EtOH and dioxane, and stable in air under light.
Here is a brief introduction to this compound(2199-44-2)Computed Properties of C9H13NO2, if you want to know about other compounds related to this compound(2199-44-2), you can read my other articles.
Reference:
Thiazolidine – Wikipedia,
Thiazolidine – ScienceDirect.com