摘要:

AbstractStepwise oxidation ofp‐tolylp‐methoxydithiobenzoate (1) gives the sulfines (thione oxides) AnC(=S=O)STol (2), AnC(=S=O)SOTol (3) and AnC(=S=O)SO2Tol (4) (An =p‐CH3OC6H4and Tol =p‐CH3C6H4). Reaction of2withp‐toluenethiol (TolSH) in the presence of Et3N furnishes AnCH(STol)SSTol (5). The sulfine4yields with TolSH/Et3N5and AnCH2SO2Tol (6), with EtSH/Et3N AnCH(SEt)SSEt (7) and witht‐BuSH/Et3N the sulfone6. The sulfine3gives with TolSH/Et3N 5 and witht‐BuSH/Et3N6. In the presence of ZnCl2all three sulfines give rise to deoxygenated products,viz. dithioesters like1and AnCSSEt (8). In the absence of a catalyst, sulfine2, with TolSH and EtSH, undergoes deoxygenation to dithioesters.Sulfine4gave with EtSH the dithioester8as the principal product, whereas with TolSH besides1and5the compound AnCH(SO2Tol)SSTol (9) was obtained. From sulfine3products were obtained that point to a disproportionation into2and4prior to the reaction of thiol with the sulfine function. In the discussion, a rationale is presented for the reactions observed. It is shown that nucleophilic attack of thiol or thiolate anion may occur at the sulfine sulfur as well as the sulfine carbon atom. In the presence of Et3N both reaction modes take place, whereas in the presence of ZnCl2attack at the sulfur seem

ISSN:0165-0513    

DOI:10.1002/recl.19760950902

出版商:WILEY‐VCH Verlag    

年代:1976

数据来源: WILEY

摘要:

AbstractOxidation of methyl (phenylsulfonyl)dithioacetate (1) withm‐chloroperbenzoic acid gave the sulfine C6H5SO2CH2C(SO)SCH3(2).Deprotonation of2with TlOEt and subsequentS‐alkylation of the thallium(I) salt with methyl iodide gave (phenylsulfonyl)ketene dimethyl dithioacetal moxonide (5). When other bases were used in the deprotonation step deoxygenated products,viz. C6H5SO2CHC(SCH3)2were obtained. Evidence is presented that oxygen is lost by an intramolecular redox reaction of an initially formed vinylsulfenic ester.The new ketene dithioacetal monoxide5reacts with malonate anions in an additon‐elimination reaction in which the phenylsulfonyl group serves as the le

ISSN:0165-0513    

DOI:10.1002/recl.19760950903

出版商:WILEY‐VCH Verlag    

年代:1976

数据来源: WILEY

摘要:

AbstractReaction ofcis‐NPCl2(NSOCl)2withn‐butylamine (molar ratio 1:2) in acetonitrile leads to a mono(amino) derivative, NPCl(NHBu) (NSOCl)2. Under the same experimental conditionssec‐butylamine gives a mixture of about equal amounts of NPCl(NH‐s‐Bu) (NSOCl)2and NPCl2NSOClNSO(NH‐s‐Bu), whiletert‐butylamine yields mainly NPCl2NSOClNSO(NH‐t‐Bu). The increasing tendency towards substitution at a sulfur atom can be ascribed to an increasing steric hindrance towards the formation of an 5N1 transition state with five coordinated phosphorus. The reaction of NPCl(NHBu) (NSOCl)2withn‐butylamine (molar ratio 1:2) gives a geminal bis(n‐butylamino) derivative, which on fluorination yields NP(NHBu)2(NSOF)2. The31P‐ and19F NMR spectra of the compoun

ISSN:0165-0513    

DOI:10.1002/recl.19760950904

出版商:WILEY‐VCH Verlag    

年代:1976

数据来源: WILEY

摘要:

AbstractOn treatment of the quaternary pyrimidinium saltsi.e.1‐methyl‐4‐phenylpyrimidinium iodide and 1‐methyl‐5‐phenylpyrimidinium iodide with cyanamide,O‐methylisouronium chloride or bis[S‐methylisothiouronium] sulfate in basic media, 2‐amino‐4‐phenylpyrimidine and 2‐amino‐5‐phenylpyrimidine are formed respectively. A ring transformation is involved in which the two‐atom fragment N(1)‐C(2) of the pyrimidine ring is replaced by an N‐C fragment of the reagent. On reacting 1‐methylpyrimidinium iodide with benzamidinium chloride or pivalamidinium chloride in a solution of sodium ethoxide in ethanol, 2‐phenylpyrimidine and 2‐tert‐butylpyrimidine are formed respectively.It is proved by15N‐labelling that this nucleophilic substitution occursviaa ring transformation in which the N(1)‐C(2)‐N(3) fragment of the pyrimidine is replaced by the N‐C‐N fragment of the amidine. These reactions are new examples of a nucleophilic substitu

ISSN:0165-0513    

DOI:10.1002/recl.19760950905

出版商:WILEY‐VCH Verlag    

年代:1976

数据来源: WILEY

ISSN:0165-0513    

DOI:10.1002/recl.19760950906

出版商:WILEY‐VCH Verlag    

年代:1976

数据来源: WILEY

摘要:

AbstractCompounds Mn(ur)n(anion)2[ur is urea (U),N,N′‐dimethylurea (DMU) andN,N′‐diethylurea (DEU),n= 2, 3, 4, 6, 10, and anion = Cl−, Br−, I−and ClO−4] have been studied by ESR, far‐IR and low‐temperature magnetic susceptibility. With U as the ligand, anion = Cl, Br andn= 2 halogen‐bridged linear‐chain compounds are formed, with oxygen‐bonded U in the axial positions. The Mn atoms in the chain are antiferromagnetically coupled withJ/Kvalues of −0.6 K (Br) and −1.0 K (Cl).Compounds Mn(U)4X2appear to be tetragonally coordinated with the anions in the axial positions. The zero‐field splittings of the ground state have been determined as 0.11 and 0.18 cm−1for X = Cl and Br, respectively. The octahedral cations Mn(ur)2+6have been studied by ESR and far‐IR spectra, and were found to be barely distorted. Mn‐O vibrations occur in the 200‐235 cm−1region. Compounds withn= 3 found for ur = DEU should be described as Mn(DEU)6MnX4(X = Cl, Br). A new type of compound (n= 3; ur = DMU; X = Cl, Br, I) all of which are nearly isomorphous, is believed to be monome

ISSN:0165-0513    

DOI:10.1002/recl.19760950907

出版商:WILEY‐VCH Verlag    

年代:1976

数据来源: WILEY

摘要:

AbstractOxygen nucleophiles such as water, alcohols and phenols, have been reacted with alkyldicyanamides (1). Selective addition to one of the cyano groups only was effected by a careful control of the reaction conditions. The reactions have been employed for the synthesis of a number of novel 1‐alkyl‐1‐cyanoureas (2), 1,2‐dialkyl‐1‐cyanoisoureas (5) and 1‐alkyl‐2‐aryl‐1‐cyanoisoureas (7). The reactivity of the cyano group in1has been explained in terms of a relatively “soft” electrophilic carbon atom. Proof of structure for the novel compounds was obtained by chemical transformations and with the help o

ISSN:0165-0513    

DOI:10.1002/recl.19760950908

出版商:WILEY‐VCH Verlag    

年代:1976

数据来源: WILEY

摘要:

AbstractThe reaction of 3‐aminopyridine with β‐keto esters followed by thermal cyclization of the corresponding 3‐aminoacrylic esters constitutes a convenient general approach to the synthesis of 1,5‐ and 1,7‐naphthyridine d

ISSN:0165-0513    

DOI:10.1002/recl.19760950909

出版商:WILEY‐VCH Verlag    

年代:1976

数据来源: WILEY

摘要:

AbstractThe asymmetric synthesis of (‐)‐(13S, 17S)‐6‐methyl‐17β‐acetoxy‐13,14‐dehydroequilinin methyl et

ISSN:0165-0513    

DOI:10.1002/recl.19760950910

出版商:WILEY‐VCH Verlag    

年代:1976

数据来源: WILEY

ISSN:0165-0513    

DOI:10.1002/recl.19760950901

出版商:WILEY‐VCH Verlag    

年代:1976

数据来源: WILEY