Alan F. Clifford

New derivatives of trifluorothiazyne

Abstract Thiazyl trifluoride (trifluorothiazyne) reacts smoothly with various organolithium compounds at −78° producing S -substituted thiazynes. This method has been used not only to produce known compounds but, also to prepare several new mono and di- S -substituted thiazynes which contain carbon-sulfur bonds. Nuclear magnetic resonance studies on these compounds indicate that the difluorothiazyl group is more strongly electron-withdrawing than -NO2, both inductively and resonantly.

The pentafluorosulfanylimination of organic and inorganic compounds

Abstract Reactions of SF 5 NCO, SF 5 NH 2 , SF 5 NSF 2 , SF 5 NSCl 2 and SF 5 NCCI 2 , with appropriate substrates have produced SF 5 NS(CH 3 ) 2 , SF 5 NCHC 6 H 5 , SF 5 NCCl 2 , SF 5 N=SCl 2 , (SF 5 N=) 2 C, (SF 5 N) 2 S and SF 5 NPCI 3 , some of which are new compounds and some of which represent improved routes to compounds previously reported.The preparations and properties of these are described.

Preparation and characterization of n-pentafluorosulfanylimine derivatives

Abstract Reactions of SF 5 NCCl 2 with sodium methoxide and phenoxide have produced both the mono- and disubstituted derivatives SF 5 NC(Cl)OR and SF 5 NC(OR) 2 . The monosubstituted derivative SF 5 NC(Cl)N(C 2 H 5 ) 2 was the sole product produced in a 2:1 molar reaction of diethylamine with SF 5 NCCl 2 . Further reaction of this chloroimine with diethylamine gave the disubstituted derivative SF 5 NC[N(C 2 H 5 ) 2 ] 2 . Other mixed disubstituted compounds SF 5 NC(R)N(C 2 H 5 )2, where R=CH 3 , CF 3 , C 6 H 5 , and OCH 3 , were also prepared. Each of the new N-pentafluorosulfanyl derivatives was characterized by IR, 1 H, 19 F and 13 C NMR, mass spectrometry and elemental analysis where possible.

Reactions of pentafluorosulfanyliminodihalosulfanes, SF5NSX2, with nucleophiles. Preparation and characterization of pentafluorosulfanylsulfinylamine, SF5NSO.

Abstract Reactions of SF 5 NSF 2 with sodium alkoxides and aryloxides have produced both the mono- and disubstituted derivatives SF 5 NS(F)OR and SF 5 NS(OR) 2 , where RCH 3 , CH 2 CHCH 2 , C 6 H 5 , p -C 6 H 4 NO 2 , p -C 6 H 4 Br, p -C 6 H 4 CN. The reaction of SF 5 NSCl 2 with AgNCO produced SF 5 NS(NCO) 2 . This diisocyanate can also be prepared from the reaction of SF 5 NSCl 2 with KOCN in liquid SO 2 . The proposed intermediate, SF 5 NSO, in the hydrolysis of SF 5 NSF 2 was prepared from the low temperature reaction of SF 5 NSCl 2 and Ag 2 O in C 6 H 5 NO 2 . The new pentafluorosulfanyl derivatives were characterized by IR, 1 H and 19 F NMR, mass spectrometry and where possible 13 C NMR and elemental analysis.

Acylations of pentafluorosulfanylamine, SF5NH2. Part II. Reactions of N-pentafluorosulfanylcarbamylfluoride, SF5NHC(O)F, and N-pentafluorosulfanylperfluorosuccinimide, SF5NC(O)CF2CF2C(O) [1]

Abstract The carbamyl fluoride SF5NHC(O)F reacts with both H2O and H2S to give the urea (SF5NH)2CO. Evidence supports that this reaction proceeds through a mechanism involving dehydrofluorination; whereas, the reagents PhLi and PCl5 serve only to dehydrofluorinate SF5NHC(O)F. The ring of the cyclic imide SF5 NC(O)CF 2 CF 2 C (O) can be readily opened by nucleophiles to give products such as SF5NHC(O)CF2CF2C(O)OH, SF5NHC(O)CF2CF2C(O)NH2, and SF5NHC(O)CF2CF2C(O)OCH3 Attempts to prepare analogous six- and seven-membered cyclic imides failed; however, mono- (SF5NHC(O)(CF2)3,4C(O)F) and disubstituted products (SF5NHC(O)(CF2)3,4C(O)NHSF5) were formed. The amide-acid fluorides are easily hydrolyzed by atmospheric moisture to the amide-acids SF5NHC(O)(CF2)3,4C(O)OH.

Reactions of N-pentafluorosulfanylurethanes and thiolurethanes with phosphorus pentachloride

Abstract Urethanes of the type SF 5 NHC(O)OR react with PCl 5 to give primarily SF 5 NCO. In only one case, where R = C 6 H 5 , was any evidence for an imine product observed. The corresponding reactions of SF 5 NHC(O)SR compounds give both SF 5 NCO and the imine product. The new compounds SF 5 N=C(Cl)SCH 3 and SF 5 N=C(Cl)SC 6 H 5 were identified by IR, NMR, and mass spectrometry.

Solvent effects in fluorine-19 NMR spectroscopy: Nonuniform shifting of the axial and equatorial fluorine resonances of the pentafluorosulfanyl group

Abstract The chemical shifts of the fluorine resonances of SF5NSF2 are given in fourteen different solvents. A change in solvent polarity was found to affect the axial fluorine of the SF5 group more substantially than the equatorial fluorines. This nonuniform shifting of the axial and equatorial fluorine resonances of the SF5 group is best explained as a trans effect and can sometimes be used to simplify complex spectra as shown in the examples SF5NHC(O)F and SF5NHC(O)CF3.

The preparation and reactions of pentafluorosulfanyl isocyanate and N,N1-bis (pentafluorosulfanyl)urea

Abstract Pentafluorosulfanyl isocyanate was prepared by the addition of carbonyl fluoride to thiazyl trifluoride in the presence of anhydrous HF or HCl. Increasing the ratio of anhydrous hydrogen flouride to the other reactants resulted in decreased yield of the isocyanate, although without the acid no isocyanate was formed. Pentafluorosulfanyl isocyanate in an excess of anhydrous hydrogen fluoride yielded the starting materials. Isolated from anhydrous hydrogen chloride-catalyzed reaction was pentafluorosulfanylcarbamyl chloride. N,N′-bis(pentafluorosulfanyl)urea was synthesized from pentafluorosulfanyl isocyanate and pentafluorosulfanylamine or from thiazyl trifluoride, anhydrous hydrogen fluoride and carbonyl fluoride. The reaction was reversed in excess anhydrous hydrogen fluoride or when the urea heated under vacuum to over 90°C. With triethylamine the urea decomposed.

Reactions of pentafluorosulfanyl isocyanate with NR3 and PR3 compounds; Preparation and characterization of novel compounds SF2NC(O)NHC(O)OCH3 and 1,4-SF5NHC(O)OC6H4OH

Abstract The reaction of Pentafluorosulfanyl Isocyanate, SF5NCO, with tertiary amines has led to 1:1 adducts which have been shown to be zwitterionic in nature by infrared and NMR spectroscopy. These adducts are far less thermally stable than the analogous fluorosulfonyl derivatives recently reported by Appel and Montenarch1. The reaction of SF5NCO with triphenyl- phosphine gave some evidence for the zwitterionic derivative, but the product could not be isolated even when SF5NCO was used in excess. Recently we have also isolated from the reaction of SFE2NC(O)NCO with methanol, and from the reaction of SF5NCO with hydroquinone. Both of these novel compounds were unexpected. The physical properties of , SF2NC(O)NHC(O)OCH3, and 1,4-SF5NHC(O)OC6H4OH, prepared during this study, will be discussed in detail.

Addition of carbonyl fluoride to aliphatic nitriles: Formation of α,α-difluoroalkyl isocyanates

Abstract Carbonyl fluoride will add to alkane- and perfluoroalkanenitriles and alkanedinitriles in anhydrous acids to form the corresponding α,α-difluoroalkyl isocyanate, perfluoroalkyl isocyanate, or α,α,ω,ω,-tetrafluoro-α,ω-diisocyantoalkane. With acetonitrile the reaction proceeded slowly in anhydrous hydrogen fluoride or in the presence of anhydrous hydrogen chloride in benzene to yield a clear colorless liquid identified as α,α-difluoroethyl isocyanate. Increasing yields based on the lesser reactant were achieved by making the ratio of acetonitrile to carbonyl fluoride greater or less than one, having the optimum amount of anhydrous acid, the presence of an alkali metal fluoride and/or an increase in reaction time. The α,α-difluoroethyl isocyanate reacted with anhydrous ethyl alcohol to form the corresponding carbamate which slowly decomposed by splitting out hydrogen fluoride. The addition reaction proceeded more rapidly with propionitrile and less rapidly with trifluoroacetonitrile than with acetonitrile. Cyanamide yielded trifluoromethyl isocyanate and cyanuric acid. Adiponitrile produced 1,6-diisocyanato-1,1,6,6-tetrafluorohexane and 1-isocyanato-5-cyano-1,1-difluoropentane.