4-Methyl-3- phenyl isothiocyanate

Ethoxy-6-methylpyrimidine 1-oxide (499) reacts with phenyl isocyanate to eliminate carbon dioxide and give a mixture of 4-ethoxy-6-methyl-N-phenylpyrimidin-2-amine (SOO) and (the derived) 7V-(4-ethoxy-6-methylpyrimidin-2-yl)-7V,7V -diphenylurea (SOI) phenyl isothiocyanate reacts quite differently (79CPB2642). 

A phenyl guanidine analogue is readily prepared by first I i acting 2-imino-]i-methylpyrrolidine with phenyl isothiocyanate III give synthon 21, This is next -methylated with methyl io-illcle to give 16 which itself, on reaction with pyrrolidine, is... 

As in the case of silanone 9, the reaction of the silylene bis[2-(dimethylamino-methyl) phenyl]silanediyl (8) with phenyl isothiocyanate was examined.29 In this reaction the expected silanethione 36 was obtained as a single product even in the presence of (Me2SiO)3, no insertion product of 36 into a Si-O bond of (Me2SiO)3 was observed (Scheme 10). 

In the reaction of 1 with methyl or phenyl isothiocyanate, the dithiasiletanes 76 or 77 were formed, following a pathway comparable to that observed for the reaction of 1 with carbon dioxide (see Scheme 28). In the case of the reaction with phenyl isothiocyanate, more drastic conditions... 

Substituted derivatives of l-(tetrahydrobenzo[b]thiophen-2-yl-3-carboxylate)-5-phenyl-6-thio-l,2,4-triazin-4-one have been synthesized by heterocyclization reactions of different hydrazones obtained from 2-amino-tetrahydrobenzo[b]thiophene-3-carboxylate with phenyl isothiocyanate <00PS275>. Reaction of 5-methyl isothiosemicarbazide with a-amino acid vicinal tricarbonyl reactive substrates 1 and 2 yields 1,2,4-triazine substituted a-amino acids, as an equimolar mixture of regioisomers 3a/3b and 4a /4b, respectively <00JCS(P1)299>. 

Dimethyl malonate was first treated dropwise with phenyl isothiocyanate in the presence of sodium hydride in N,7V-dimethylacetamide at 0°C. The reaction mixture was stirred at ambient temperature for 1.5 hr and then cooled to 0°C, and methyl iodide was added dropwise. After stirring for 4 hr at room temperature, (methylthio)(phenylamino)methy-lenemalonate (341) was obtained in 79% yields (69T4649). 

Further routes of cyclizations have been studied in parallel in the case of cis- and rra/J5-2-hydroxymethyl-l-cyclohexylamine (106) (880PP73). The preparation of thiourea or urea adducts 107 and 108 with phenyl isothiocyanate or phenyl isocyanate proceeds smoothly. The reaction of 107 with methyl iodide and subsequent alkali treatment, by elimination of methyl mercaptan, resulted in the iminooxazine 109 in high yields. The ring closures of both cis and trans thiourea adducts to 1,3-oxazines proceed with retention. Cyclodesulfuration of the adduct 107 by mercury(II) oxide or N,N -dicyclohexylcarbodiimide resulted in the iminooxazine 109, but the yield was low and the purification of the product was cumbersome. The ring closure of 108 with thionyl chloride led to the iminooxazine 109 in only moderate yield. 

Methyl-5-phenylimino-l,2,3,4-thiatriazoline (70) reacts with phenyl isothiocyanate at RT under nitrogen evolution to give compound (71) (R = Ph) as the main product (Equation (7)) <77JOCi 159>. 

A successful method for preparing 1,3-thiazetidines is the cycloaddition of carbodiimides with isocyanates. The cycloadduct 151 was derived by the interaction of carbodiimide 152 and tosyl isothiocyanate . Reaction of 152 with methyl or phenyl isothiocyanate preferentially leads to iminotriazine-thiones. Cycloaddition between aryl isothiocyanates and dicyclohexylcar-bodiimide produced 153. ... 

Phenyl isothiocyanate reacts less readily with alkynyllithium than methyl isothiocyanate. The thioamide from the reaction of CHjC=CLi with PhN=C=S is not easy to obtain in a crystalline state. 

Bismethylthio)methylene]- and 6-[(methylthio)(phenylamino)meth-ylene]- derivatives of 6,7,8,9-Tetrahydro-117/-pyrido[2,l-6]quinazolin-ll-ones (125 and 126) were obtained from 6,7,8,9-tetrahydro-l 1 //-pyrido[2,l-b]quinazolin-ll-one (7) with carbon disulfide and phenyl isothiocyanate, respectively, in dimethylsulfoxide in the presence of sodium hydride, and then methylation with methyl iodide (86ZC251). 

In a uniform reaction, 45f undergoes cycloreversion to phenyl isothiocyanate and methyl azide (path B). The products corresponding to path A... 

Most probably sulfur is not cleaved from the products after cycloreversion, because methyl, ethyl, and phenyl isothiocyanate are stable under the pyrolysis conditions. 

However, the reaction of the binuclear rj2-thioaldehyde titanocene complexes 112 (see Scheme 26) with valeronitrile, benzonitrile, and methyl thiocyanate proceeded in a similar fashion (Scheme 39).69 Related metalla-cyclic compounds were also obtained from the reactions of 112 with benzo-phenone (Scheme 39), various imines, phenyl isothiocyanate, or dicyclohexyl carbodiimide via insertion of the C = 0 and C = N bond, respectively, into the Ti-C bond.69,70... 

Remark. The procedure described in Section 2.8.3 for the synthesis of -V-phenyl imidothioesters gave poor results in the case of methylmagnesium iodide, mainly because of low stability of its addition product to phenyl isothiocyanate. A good yield could be secured by running the reaction at a lower temperature in ether as the solvent and addition of HMPA in the methylation step. Filtration on a very short column of silica (eluent petroleum ether/ethyl acetate 97.5 2.5) afforded a quite pure product in a 79% yield. 

Silanethione 80 was also postulated as an intermediate in the reaction of silicocene 41 with isothiocyanates (room temperature/toluene/16 h for methyl isothiocyanate and 65 °C/toluene/5 h for phenyl isothiocyanate), which resulted in the formation of the corresponding intermolecular [2 + 2] cycloadducts (82 and 83) of 80 with the isothiocyanates (Scheme 30)41a b. Under even more drastic conditions (100°C/toluene/20 h), the reaction of 41 with phenyl isothiocyanate gave the five-membered heterocycles 84, which is most likely produced by a second attack of the silicocene 41 on the initially formed [2 + 2] cycloadduct 83 (Scheme 30). 

Method. 1.5 jzmoles of peptide or amino acid are dissolved in 1 ml of 60% aqueous pyridine containing 15 mg of methyl isothiocyanate (M1TC) or phenyl isothiocyanate... 

Phenoxyacetophenone was thiocarbamoylated by treatment with phenyl isothiocyanate in the presence of potassium /frt-butoxide and methyl iodide to afford 1,3-thiazetidine derivative 192 in 28% yield <1996SUL1> (Scheme 62). 

Recent results. Riddel et al.40 have reported the spectral parameters of some significant sulphur compounds, including some previously unobserved functional groups phenyl isothiocyanate (PhNCS), methyl thiocyanate (MeSCN), thiophenol (PhSH), methyl phenyl sulphide (PhSMe), 2-methylthiazole,... 

One of the earliest methods for synthesizing 1,2,3-thiadiazoles is that of Pechmann and Nold (B-61MI42400), who reacted diazomethane with phenyl isothiocyanate (equation 25). Of the four possible isomers only 1,2,3-thiadiazole (30) was formed. This method is somewhat restricted as methyl isothiocyanate does not react with diazomethane at room temperature. 

Carbanions derived from 5-alkyl-l,2-dithiole-3-thiones react with carbon oxysulfide or disulfide, or with phenyl isothiocyanate, to give dianions which can be methylated as shown in Scheme 8. 

In the sequential degradation according to the Edman procedure methyl or phenyl-isothiocyanate is used as the reagent and the reaction starts from the amine end of the... 

A new synthetic route to tetraaminoethene derivatives developed by Gorls and coworkers95 involves a reduction/substitution sequence the oxalic amidines, 123, were reduced with lithium under sonication affording 124, and the subsequent addition of phenyl isothiocyanate, 125, afforded the anionic bis(thiocarbamoyl) derivatives 126. Treatment of 126 with methyl iodide gave, in a nearly quantitative yield, the isothiourea derivative 127 (Scheme 40)96. 

It is a general rule that imidazoles and benzimidazoles are resistant to Friedel-Crafts reactions. This is not surprising since such basic compounds must be markedly deactivated in the presence of Lewis acids. Imidazolin-2-ones appear to be an exception and apparently possess sufficient activation to react. Reactions between imidazoles and Af-methylfor-manilide and phosphoryl chloride are also unproductive. With 4,5-diphenylimidazole, phenyl isocyanate at 80 °C gives products of both N- and C-substitution, but in boiling nitrobenzene only the latter (86) is formed. 2-Methyl-4-phenylimidazole gives (87) under the same conditions, and 1,3-diphenylimidazolium perchlorate is transformed by potassium t-butoxide into a ylide which reacts at C-2 with phenyl isothiocyanate. Sufficient activation is present in l-methyl-2-phenyl-4-phenylaminoimidazole for it to react by substitution at C-5 with acetic anhydride (71JOC3368). 

Cyclization of thioureidoimidazoles in the presence of sulfur-extracting agents such as mercury salts may favour 2-aminopurine formation. Thus 5-aminoimidazole-4-(iV-methyl)carboxamide (354) and some 2-substituted derivatives with phenyl isothiocyanate afforded the phenylthioureidoimidazole which when heated with mercury(II) salts produced 1,N-dimethylisoguanine and 8-substituted derivatives (355), respectively (Scheme 146) (50JCS1888). 

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