Synthesen in der Purinreihe, VI. Mitteil.¹⁾: Synthesen mit 4‐ und 5‐Amino‐uracil

Abstract

Breder ec k, Edenkofer : [ Jahrg. 88 60 ccm Wasser und 100 ccm Athano1 hinzugefugt und 2 Stdn. unter RiickfluB zum Sieden erhitzt. Anschliehnd dampfte man den Alkohol ab, versetzte mit 60 ccm 20-proz. w&Br. Natronlauge, kochte nochmals 2l/, Stdn. und filtrierte nach dem Abkiihlen von Spuren amorpher Substanz ab. Unter Riihren und Kiihlen wurde die alkahche Lijsung d m h troptenWeise Zugabe von etwa 45 ccm konz. Salzsiiure auf 1 gebmcht (Vorsicht, BlausiLure-Entwicklung!), noch Stde. auf 0 0 gekiihlt, dann das ausgefallene Heteroa u x i n abgesaugt und mit wenig eiskaltem Waaser gewaschen. Ausb. 3.39g (97% d.Th.) vom Schmp. 155-160O (Sintern ab 145O). Bus Waaaer erhiilt man XXVI in 75-80-proz. Ausbeute mit dem Schmp. 164-165O; keine Schmp.-Erniedrigung mit authent.80) XXVI vom gleichen Schmp. Aus Gmmin erhielten wir unter den gleichen Bedingungen nur etwa 30% reines Heteroauxin.

Novel reaction of uracil derivatives possessing electron-withdrawing groups at the 5-position with amines: exchange reaction between the N1-portion of uracils and amines

“…underwent the "-exchange reaction upon treatment with methylamine at 60 "C to give 5-carbamoyl-1,3-dimethyluracil (7b) (run 14), whose structure was confirmed by an alternative synthesis.' In the reactions with propylamine, butylamine, and ethanolamine, more drastic conditions (heating at 120 *C in a sealed tube) were required (runs [15][16][17]. On the other hand, treatment of 5-carbamoyl-l,3-dimethyluracil(7b), which has no phenyl group at the N'-position, with butylamine under various conditions resulted in the recovery of the starting material.…”

“…A mixture of compound (3) (0.50 g, 1.41 mmol) and triethylamine (0.47 g, 4.65 mmol) in ethanol (20 ml) was stirred at room temperature for 6 h. The resulting precipitate was filtered off and washed with ether to give compound (la) (0.24 g, 92%), which was identical with an authentic sample. 16 Reaction with ethylamine. A mixture of compound (3) (0.32 g, 0.9 mmol) and aqueous ethylamine (70%) (0.58 g, 9 mmol) in ethanol (20 ml) was stirred at room temperature for 10 h. The solvent was removed under reduced pressure and the residue was chromatographed on a silica gel column with chloroformmethanol (100: 1) as the eluant to give compounds (la) (0.05 g, 27%) and (li) (0.14 g, 71%).…”

“…The resulting precipitate was filtered off and recrystallized from acetic acid to give the title compound (14b) ( (0.50 g, 1.8 mmol) and cyclohexylamine (3.60 g, 36 mmol) in ethanol (17 ml) was refluxed for 1.5 h. The resulting precipitate was filtered off and recrystallized from acetic acid to give the title compound (14) (14200) (Found: c , 51.1; H, 5.15; N, 18.65. C16H19N506 5-Cyano-6-methyl-1 -phenyluracil (Ha).-A suspension of compound (16) (see later) (0.29 g, 1.12 mmol) in ethanolic sodium ethoxide [prepared from Na (0.23 g, 10 mg-atom) in absolute ethanol (30 ml)] was stirred at room temperature for 12 h. The solvent was removed under reduced pressure and the residue was dissolved. in water.…”

Pyrimidine derivatives and related compounds. Part 48. Uracil ring transformation: conversion of 5-nitrouracils into 5-carbamoyluracils

“…> 300 "C (lit.," > 300 "C) (Found: C, 55. 75 Cl1H15N303: C, 55.7; H, 6.35; N, 17.7%); S[(CD3),SO] 1.05-2',3',5'-Tri-O-benzoyl-3-methyl-5-nitrouridine (7).-A mixture of the 5-nitrouridine ( 6)" (3.0 g, 5 mmol) and dimethylformamide dimethyl acetal (1.78 g, 15 mmol) in dimethylformamide (7 ml) was stirred at room temperature for 30 min. The solvent was removed under reduced pressure and the residue was subjected to column chromatography (silica gel, chloroform) to afford 2',3',5'-tri-O-benzoyl-3-methyl-5-nitrouridine (7) (2.55 g, 83%).…”

Thermal studies on Ni(II), Cu(II) and Pd(II) complexes of 6-amino-5-formyluracil and its N-methyl derivatives

“…For this reason and in connection with our studies on the synthesis, characterization and thermal behaviour of derivatives of biological importance [14][15][16][17][18][19][20][21][22], we describe here the thermal behaviour of tJour pyrimidine derivatives, 6-amino-5-formyluracil (HFU), 6-amino-l-methyl-5-formyluracil (1-HFU), 6-amino-3-m~thyl-5-formyluracil (3-HFU) and 6-amino-l,3-dimethyl-5-formyluracil (HDFU), and the new Ni(II), Cu(II) and Pd(II) complexes of these pyrimidine derivatives. Experimental HFU and its N-methylated derivatives were synthesized according to Pfleiderer [22], using 6-aminouracil and its methylated derivatives as starting materials [23][24]. The results of elemental analysis are given in Table 1.…”