Collection of Czechoslovak Chemical Communications published new progress about 19959-71-8. 19959-71-8 belongs to pyrazoles-derivatives, auxiliary class Pyrazole,Pyridine, name is 4-(1H-Pyrazol-4-yl)pyridine, and the molecular formula is C8H7N3, SDS of cas: 19959-71-8.
Arnold, Z. published the artcileSynthetic reactions of dimethylformamide. XVI. Formylalion of γ-picoline, SDS of cas: 19959-71-8, the publication is Collection of Czechoslovak Chemical Communications (1963), 863-8, database is CAplus.
cf. CA 59, 439h. Treatment of γ-picoline (I) with (Me2NCH:NMe2)+ClO4– (II) gave 4-(β-dimethylaminovinyl)pyridine (III) which reacted with IICONMe2 (DMF) and COCl2 to give α-(4-pyridyl)-β-dimethylaminoacrolein (IV), also obtained by treatment of I with DMF and COCl2 or POCl3. Alk. hydrolysis of IV afforded 4-pyridylmalonic dialdehyde (V). V with N2H4 gave 4-(4-pyridyl)pyrazole (VI), with H2NCONHNH2 (VII), 4-(4-pyridyl)pyrazole-1-carboxamide (VIII), with H2NCSNHNH2 (IX), α-(4-pyridyl)-β-thiosemicarbazinoacrolein (X), and with NH3, 5-(4-pyridyl)pyrimidine (XI). To a mixture obtained from 0.26 g. Na and 100 ml. liquid NH3, 1.86 g. I was added at -60°, followed, after 15 min., by 4 g. powd. II. After cooling and stirring for 15 addnl. min., the NH3 was evaporated, the residue treated with 20 ml. C6H6 and 3 ml. H2O, the aqueous layer extracted with C6H6, the extract washed with H2O, dried, filtered, and evaporated to give 1.55 g. (52%) III, m. 101-2° (MeCOEt at -60°). Adding 1.5 g. III to a solution prepared by adding 5 ml. 3N COCl2 in CHCl3 to 3.65 g. DMF in 25 ml. CHCl3, stirring the mixture 30 min. at room temperature, refluxing 6 hrs., treating with a saturated solution of K2CO3, extracting with 1:1 C6H6-EtOH, evaporating, and extracting the residue with C6H6 gave 1.4 g. (79%) IV, Rf 0.65 (Whatman Number 4 paper in MeCOEt-H2O), m. 90-2° (MeCOEt at -70°), also obtained by adding 1.86 g. I to a reagent prepared from 21.9 g. DMF and 9.2 g. POCl3, heating the mixture 6 hrs. at 70°, adding it to 70 ml. saturated solution of K2CO3 covered with 30 ml. 1:1 C6H6EtOH, filtering the salts, extracting the filtrate with the above mixture, drying the extract with anhydrous K2CO3, evaporating, extracting the residue with C6H6, and evaporating to dryness in vacuo, yield 3.2 g. (91%) crude, 2.4 g. (68%) pure. IV was also obtained in 51% yield by stirring a mixture of 0.93 g. I in 3 ml. CHCl3, 7.3 g. DMF in 25 ml. CHCl3, and 10 ml. 3N COCl2 in CHCl3 1 hr. at room temperature and 5 hrs. at reflux. Heating 0.176 g. IV with 0.11 g. 50% KOH and a few drops H2O to 70°, cooling the mixture, precipitating with concentrated KOH a potassium salt of V, filtering it off with suction, dissolving in H2O, and acidifying the solution gave V, m. >320° (H2O), also obtained in 80% yield by heating a mixture of 21.9 g. DMF, 9.2 g. POCl3, and 1.86 g. I 6 hrs. at 70°, cooling, treating with 70 g. ice and a solution of 12 g. NaOH in 20 ml. H2O at 20°, heating the mixture 10 min. at 90°, cooling, and acidifying with 1:1 HCl to pH 7. Treatment of 0.15 g. V with an equal amount of 90% N2H4 afforded VI, m. 198-9° (H2O). Mixing a solution of 0.15 g. V in 6 ml. N HCl with a solution of 0.11 g. VII.HCl in 3 ml. N HCl gave VIII, m. 230°. Similar treatment of V with 0.09 g. IX gave X, m. 200°. Heating 0.3 g. V with 10 ml. NH3 in EtOH 3 hrs. at 120° in a stainless steel autoclave, filtering the mixture with activated C, and evaporating in vacuo gave 0.12 g. XI, m. 107.5-8.5° (MeCOEt).
Collection of Czechoslovak Chemical Communications published new progress about 19959-71-8. 19959-71-8 belongs to pyrazoles-derivatives, auxiliary class Pyrazole,Pyridine, name is 4-(1H-Pyrazol-4-yl)pyridine, and the molecular formula is C8H7N3, SDS of cas: 19959-71-8.
Referemce:
https://en.wikipedia.org/wiki/Pyrazole,
Pyrazoles – an overview | ScienceDirect Topics