Small Charged Rings. VII. Interconversion of Substituted β-Chloroethylamines and Aziridinium Salts^1-3

Abstract

Small Charged Rings. VII 821 was no longer present. The bulk of the reaction mixture was added dropwise with stirring to 100 ml. of anhydrous ether. The colorless solid was washed with ether: 0.62 g. (95%), identical with earlier preparations of 3-benzyl-2-methyl-l,3-diazaspiro-[4.5]dec-l-ene perchlorate.G.-A glass rod was dipped into 72% aqueous perchloric acid, shaken free of adhering drops of acid and then dripped into a suspension of 0.100 g. (0.27 mmole) of 3-benzyl-3-ethyl-2-methyl-laza-3-azoniaspiro[4.5]dec-1 -ene perchlorate in 10 ml. of water. The mixture was warmed on a steam bath until solution was complete (ca. 3 min., maximum temperature of mixture 78°), cooled, and extracted with four 5-ml. portions of ether. Evaporation of the aqueous solution gave 0.070 g. (92%) of solid product identical with other samples of 3-ethyl-2-methyl-l ,3-diazaspiro[4.51dec-1-ene perchlorate. The ether extract was dried (Na2S04), and concentration gave a few drops of an oil which on vapor phase chromatography (silicone rubber column, 175°) gave a single peak identical in retention time with that of benzyl alcohol under the same conditions. l-Benzyl-3-ethyl-2-methyl-3-aza-l-azoniaspiro[4.5]dec-l-ene Perchlorate (IV).-To a stirred suspension of 0.73 g. (2.6 mmoles) of 3-ethyl-2-methyl-l ,3-diazaspiro [4.5] dec-1 -ene perchlorate in 10 ml. of water were added 2.8 ml. of 1 N sodium hydroxide solution and 10 ml. of ether. The mixture was stirred for 15 min. and separated; the aqueous phase was further extracted with four 5-ml. portions of ether. The combined ether solution was dried (MgSÓ4) and treated with 0.321 ml. (462 mg.; 2.7 mmoles) of benzyl bromide. The sirupy residue (0.58 g.) resulting from evaporation of the solvent could not be made to crystallize: si¡« 1610 and 1555 cm.-1. A solution of the sirup in 17 ml. of methanol was treated with 344 mg. (1.66 mmoles) of silver perchlorate in 10 ml. of methanol. Filtration afforded 301 mg.(96%) of silver bromide. The methanol solution was concentrated and treated with ether. The sticky solid was recrystallized from ethyl acetate: 0.51 g. (83%); m.p. 120-121°; v™ 1615 and 1560 cm.-1; n.m.r.-values (CDC13, TMS) 2.66 (5H, aromatic protons), 5.31 (s, 2H, benzyl CH2), 6.16 (s, 2H, imidazolinium CH2), 6.34 (?,«/ = 7 c.p.s., 2H, CH2CH3), 7.77 (s 3H, 2-CH3), 7.9-8.9 (unresolved m, 10H, cyclohexane protons), and 8.67 p.p.m. (t, 3H, CH2CH3).

Synthesis of 2-chloro-N,N,N-trialkylethanaminium salts and related hydroxy-analogues as analytical standards for monitoring potential chemical warfare agent precursors

“…(quartet) and 3.92 ppm (singlet). 19 However, proton signals in 1,1-diethylaziridium cation were observed at 1.36 (triplet), 3.08 (singlet) and 3.28 (quartet) ppm. 19 Thus, the chemical shift of the singlet signal assigned to ring methylene protons is a clue to discriminate between the 3-or 6-membered rings.…”

“…19 However, proton signals in 1,1-diethylaziridium cation were observed at 1.36 (triplet), 3.08 (singlet) and 3.28 (quartet) ppm. 19 Thus, the chemical shift of the singlet signal assigned to ring methylene protons is a clue to discriminate between the 3-or 6-membered rings. We observed the signal in the range typical of piperazinium species which was also supported by 13 This chair-to-chair exchange is relatively fast at 27 °C, the temperature of NMR measurements, thus detection of the signal is difficult.…”

Zurückziehung: Stable Aziridinium Salts as Versatile Intermediates: Isolation and Regio‐ and Stereoselective Ring‐Opening and Rearrangement

“…[5] Research efforts have been made to characterize aziridinium salts, and formation of several aziridinium salts was induced by using heavy counter anions such as fluoroborate or perchlorate. [6] Herein, we describe the synthesis and characterization of a series of aziridinium salts obtained from the bromination of N,N-dicarboxymethylated b-amino alcohols. To our knowledge, this is the first report on the isolation of a series of stable aziridinium cations prepared directly from b-amino alcohols under mild conditions.…”

Phase-Transfer catalyzed alkylation of morpholine with 1,2-dichloroethane

“…Based on these data, we can assume that the reaction of 1-(2-chloroethyl)morpholine II with morpholine I occurs as a direct nucleophilic substitution of the chlorine atom by the S N 1 mechanism [3], but not through the formation of an intermediate compound IV [1,4]. …”