Oxalyl‐isothiocyanate und Carbonyl‐halogenid‐isothiocyanate

Abstract

Synthesen von Ethoxalyl-isothiocyanat (l), Oxalyl-diisothiocyanat (3), Oxalyl-chlorid-isothiocyanat (4) und Oxalyl-bromid-isothiocyanat (16) werden beschrieben. Durch thermische Decarbonylierung von 4 bzw. 16 erhalt man das Carbonyl-chlorid-isothiocyanat (7) bzw. Carbonylbromid-isothiocyanat (17). Es werden einige Urnsetzungen der neuen Oxalyl-und Carbonyl-pseudohalogenide angegeben. Trichlormethyl-isocyaniddichlorid (12) wird in das Trichlormethyl-isothiocyanat (13) iibergefiihrt. Oxalyl Isothiocyanates and Carbonyl Halogenide IsothiocyanatesPreparations of ethoxalyl isothiocyanate (l), oxalyl diisothiocyanate (3), oxalyl chloride isothiocyanate (4), and oxalyl bromide isothiocyanate (16) are described. Thermal decarbonylation of 4 and 16 leads to carbonyl chloride isothiocyanate (7) and carbonyl bromide isothiocyanate (13, resp. Some reactions of the new oxalyl and carbonyl pseudohalogenides are given. Trichloromethyl isothiocyanate (13) is obtained from trichloromethyl isocyanide dichloride (12).Wir fanden, d& sich Oxalyl-halogenide mit Ammoniumrhodanid in fliissigem Schwefeldioxid in hohen Ausbeuten zu Oxalyl-isothiocyanaten umsetzen.So erhalt man aus Ethoxalyl-chlorid das Ethoxalyl-isothiocyanat (l), eine bei -18°C einige Monate stabile, im Vakuum unzersetzt destillierbare Fliissigkeit von scharfem, zu Tranen reizendem Geruch. Irn IR-Spektrum (Film) zeigt 1 eine intensive Isothiocyanatbande urn 1940 cm-' und zwei Carbonylschwingungen (1720, 1750 crn-I). Das "C-NMR-Spektrum (CDCI,, 313 K) weist u. a. einen Isothiocyanatkohlenstoff bei 6 = 153.2 auf. Mit Anilin reagiert Ethoxalyl-isothiocyanat (1) ausschlienlich unter Substitution der Isothiocyanatgruppe zum Anilid 2.

Spectroscopic Characterization and Constitutional and Rotational Isomerism of ClC(O)SCN and ClC(O)NCS

“…The 13 C NMR spectrum of ClC­(O)­SCN shows two singlets with chemical shifts of 158.9 and 105.6 ppm, which are assigned to the carbon atoms of the C­(O) and SCN groups, respectively (Figure S2). The 13 C NMR spectrum of ClC­(O)­NCS is in accordance with previous experiments (δ = 140.5 ppm (CO) and δ = 154.2 ppm (NCS)) . Both 13 C NMR spectra agree well with chemical shifts reported for related compounds .…”

“…The 13 C NMR spectrum of ClC(O)NCS is in accordance with previous experiments (δ = 140.5 ppm (CO) and δ = 154.2 ppm (NCS)). 10 Both 13 C NMR spectra agree well with chemical shifts reported for related compounds. 9 The UV− visible spectra of both gaseous isomers are shown in Figure S3.…”

“…Both, ClC­(O)­NCS and ClC­(O)­SCN, are colorless liquids at room temperature. The isothiocyanate isomer melts at −89 °C and the vapor pressure over the temperature range −54 to 20 °C follows the equation ln p v [atm] = −4650(42) (1/ T [K]) + 12.0(2) (Figure S1 in Supporting Information, uncertainty of the linear fit are quoted in parentheses), which leads an extrapolated boiling point of 115(2) °C. On the other hand, ClC­(O)­SCN melts at −6 °C, and its vapor pressure at 15 °C is 8 mbar.…”

A Crystallographic, Spectroscopic, and Computational Investigation of Carbonyl and Oxalyl Diisothiocyanate

“…Only one publication from 1981 describes its synthesis, which proceeds from oxalyl chloride and ammonium thiocyanate in liquid SO 2 , claiming the reaction in THF to be unfeasible (see Scheme 1). 6 Characterized only by 13 C nuclear magnetic resonance (NMR) and infrared (IR) spectroscopy, its further chemistry was not explored.…”

NG-Hydroxyguanidines from Primary Amines

“…The ideal reagent in this case would be BocNCS allowing for a straightforward deprotection of the product N G -hydroxyguanidine under mild acidic conditions. BocNCS, however, is not readily prepared via standard procedures (numerous attempts at acylation of KNCS with Boc 2 O or BocF 17 failed to yield BocNCS) and so we turned our attention to improving the preparation of CbzNCS. The reaction of benzyl chloroformate with KNCS has been previously described along with the problematic, competitive decarboxylation reaction to yield benzyl thiocyanate .…”