Propyne-, sodium

A suspension of 0.35 mol of sodium amide in 400 ml of liquid ammonia was prepared in the usual way (e./. Chapter II, Exp. 11) (note 1). To this suspension was added with swirling 0.30 mol of 1-methylthio-l-propyne, in portions of about 10 g, waiting about 10 s after the addition of each portion. Swirling was continued for 1.5 min after the addition of the last portion. Immediately thereafter the... 

Isothiazole itself is best prepared by the reaction between propynal, ammonia and sodium thiosulfate (see Section 4.17.9.3). A wide range of substituted mononuclear isothiazoles can be obtained by oxidative cyclization of y-iminothiols and related compounds (see Section 4.17.9.1.1). Substituents at the 3-position need to be in place before cyclization, but 4-substituents are readily introduced by electrophilic reagents (see Section 4.17.6.3), and 5-substituents via lithiation (see Section 4.17.6.4). 

After the initial claim of the synthesis of an oxirene (by the oxidation of propyne Section 5.05.6.3.1) this system reappeared with the claim 31LA(490)20l) that 2-chloro-l,2-diphenyl-ethanone (110) reacted with sodium methoxide to give diphenyloxirene (111), but it was later shown (52JA2082) that the product was the prosaic methoxy ketone (112 Scheme 97) (the formation of 111 from 110 would be an a-elimination carbene-type reaction). Even with strong, nonnucleophilic bases, (110) failed to provide evidence of diphenyloxirene formation (64JA4866). 

Ethyleneimine reacts with (p-tolylsulfonyl)acetylene to give only the (Z)-product 115 via trans addition (equation 91), while primary and secondary aliphatic amines afford ( )-products76. With nonterminal acetylenes such as l-(ethylsulfonyl)-l-propyne, the reactions of ethyleneimine, n-propylamine and f-butylamine give mixtures of ( )- and (Z)-adducts. The double conjugate addition of sodium sulfide, selenide and telluride to bis(l-propynyl)sulfone (116) produces heterocycles (117) as illustrated in equation 9277. 

Propanol Propene Propyl acetate Propylbenzene Propyl formate Propyl nitrate Propyne Pyridine Quinoline Sodium Styrene... 

Potassium permanganate Potassium sodium alloy 2-Propyn-l-ol Organic or readily oxidizable materials Air, carbon dioxide, carbon disulfide, halocarbons, metal oxides Alkali metals, mercury(II) sulfate, oxidizing materials, phosphorus pentoxide, sulfuric acid... 

Pyrazine 168 underwent cross-coupling with propyne in the tri-o-tolylphosphine, and copper(l) iodide to provide 170. The isocyanate or methyl chloroformate and sodium hydride to give An isolated example of the synthesis of chiral pteridines from a (Scheme 33). 2-Isothiocyanatopyrazine-3-carboxylates have been isothiocyanatopyrazine-2-carboxylate 172 reacted with R)- —) provided the pteridine derivative 173 and uncyclized pyrazine with pyridine precursors afforded pyrido[2,3 Pytitnidines. 

Method B. To a pressure bottle is added a solution of 0.100 gm of 1 -(p-biphenyl)-3-phenyl-l-propyne in 50 ml of petroleum ether (b.p. 20°-40°C) with 1.0 gm of sodium hydroxide pellets. The solution is kept for 11 hr at room temperature. After this time the solution is filtered and concentrated as in Method A to afford 0.058 gm (58%) of 1 -(p-biphenyl)-3-phenylallene, m.p. 

The suspension 1s cooled to 20°C on 1ce and then 800 mL of 1.4 M aqueous sulfuric acid is cautiously added over 0.75 hr so that the temperature remains below 45°C. The resulting solution is stirred for 5 min and then 600 mL of ether is added. Both phases are transferred to a 4-L separatory funnel and the layers are separated. The aqueous phase is extracted twice with 400-mL portions of ether and all ether layers are individually washed in series with two 1-L portions of water and once with 800 mL of saturated sodium chloride solution. The combined organic extracts are dried over magnesium sulfate and concentrated by rotary evaporation. The yellow-brown residue is purified by short path distillation to afford 82-86 g (91-94 yield) of 3-trimethylsilyl-2-propyn-l-ol as a clear, colorless liquid (Note 7), bp 76°C (20 mm) (Note 8). 

A-5. Treatment of propyne in successive steps with sodium amide, 1 -bromobutane, and sodium in liquid ammonia yields as the final product. ... 

The incorporation of propyne and 1-hexyne into alkynyliodonium salts with HTIB and its mesyloxy analog has been accomplished with the aid of a silica bead desiccant (equation ll)5,6, but the yields of the products are low. A better method for the synthesis of alkynyliodonium tosylates in which R is a linear alkyl group entails the treatment of (trimethylsilyl)alkyne/iodosylbenzene mixtures in chloroform with boron trifluoride etherate. When aqueous sodium tosylate is added to the resulting solutions, alkynyliodonium tosylates are produced and can be isolated from the organic phase (equation 12)7. The... 

The addition of sodium benzenetellurolate to 3-hydroxy-l-propynes produces (Z)-2-hydroxyalkylethenyl phenyl telluriums. These compounds treated with carbon monoxide in dichloromethane in the presence of stoichiometric amounts of triethylamine and palladium(II) chloride are carbonylated and the resulting acids converted to lactones1. 

Dimcthyl-4-oxo-4-phenyl-/>v-4//-l,4-teUuraphosphorm This reaction must be performed under a nitrogen atmosphere. 17.4 g (100 mmol) of disodium telluride are prepared from 4.6 g (200 mmol) of sodium and 12.8 g (100 mmol) of tellurium in liquid ammonia. When the reaction between sodium and tellurium is complete, 175 ml of methanol are cautiously added to the sodium telluride suspension in liquid ammonia. The ammonia is allowed to evaporate, and the mixture is then heated on a water bath kept at 40". Methanol is added to bring the volume to 150 ml. 6.1 g (30 mmol) of bis[l-propyn-l-yl](phenyl)phosphine oxide are added, the mixture is stirred for 5 h, 500 ml of ice/water are added, and the resultant mixture is extracted several times with chloroform. The combined extracts are filtered, and the filtrate is washed with water, dried with anhydrous magnesium chloride, and filtered. The solvent is evaporated from the filtrate under aspirator vacuum and the residue is recrystallized several times from toluene yield 7.0 g (71%) m.p. 179-182". Similarly prepared were the following compounds1 ... 

In this sequence29,30 a (substituted or unsubstituted) benzophenone (15) is reacted witb sodium acetylide (16) in an etber solvent at room temperature to yield a 1,1-diaiyl-2- propyn-l-ol (17). This intermediate can be condensed with a P-naphthol in the presence of an acid catalyst at 30 to 50°C to yield the pyran. 

To a 500-ml reaction flask were added, l,l-diphenyl-2-propyn-l-ol (0.1 mol, 20.8 g, Farchan Laboratories), 2-naphthol (0.11 mol, 15 g) and 200 ml of toluene. The mixture was warmed to 55°C with stirring while dodecylbenzenesulfonic acid was added dropwise until a permanent dark red-black color was obtained. The temperature was maintained at 55°C until thin-layer chromatography (TLC) indicated the reaction was complete (approximately 1 h). Then the mixture was poured into an equal volume of 10% aqueous sodium hydroxide, shaken, and the organic fraction separated. The toluene solution was washed with water, phase separated, and the solvent removed on a rotary evaporator. The resulting light tan crystals were slurried with hexane, suction filtered, and dried to yield 18.4 g of product with a melting point range of 156-158°C. 

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