VOL. 29148". The hydrochloride melted at 149-151", lit.B m.p. 148-151 O . N,N-Bis( 2-hydroxy-1-naphthylmethy1)isopropylamine (IIe).-The yield was 837,, m.p. 125-126", after recrystallization from methanol-I-dimethylformamide (6 : 1).Anal. Calcd. for C26H26NOZ: C, 80.83; H, 6.75. Found: C, 80.53; H, 6.95.The hydrochloride melted a t 163-164", after recrystallization from methanol.Anal. Calcd. for Cz,Hz6C1NOz: C1-, 8.69. Found: C1-, 8.73.Treatment of 1-t-Octylaminomethyl-&naphthol (IIIg) with Hot Ethanol.-l-t-Octylaminomethyl-2-naphthol ( 2 . 5 g.) was warmed to 50 -.%' in 30 ml. of 95y0 ethanol for 5 min. and then kept a t room temperature for 2 days. Removal of the solvents under reduced pressure gave an oil which was dissolved in 100 ml. of ether. The resulting solution was extracted with 100 ml. of water containing 2 g. of sodium hydroxide. The ether extract was washed with water and dried over sodium sulfate. Evaporation of the ether gave a solid, m.p. i8-80". It was recrystallized from 9,io/c ethanol to yield 0.45 g. (347@), m.p. 82-83'; mixture melting point with an authentic sample of 2-t-octyl-IH-2,3-dihydronaphth[l,2-e] [1,3]oxazine, m.p. 83-84', gave no depression. Upon adding 37% hydrochloric acid to pH 1, a white solid separated. It readily dissolved in ether. Removal of the ether gave 0.95 g. (73% yield) of bis(2-hydroxy-1-naphthy1)methane; melting The aqueous extracts were washed with ether. (12) 0. Manasse, Ber., 87, 2409 (1894). point and mixture melting point with authentic specimen was 200-202", lit.12 m.p. 200". The aqueous extracts were neutralized with potassium bicarbonate and extracted with ether. Removal of the ether gave only a trace of oil. N-Cyclohexyl-N-(2-acetoxy-l-naphthylmethyl)acetamide .-Acetic anhydride (10 g., 0.12 mole) was added to a solution of 4 g. of I-cyclohexylaminomethyl-2-naphthol (0.016 mole) in 20 ml. of pyridine cooled on an ice bath. After 24 hr. a t room temperature, 70 ml. of water was added. Upon cooling 4.8 g.(887@ yield) of solid, m.p. 107-108", separated. The product was recrystallized twice from methanol containing a trace of water, m.p. 108-109".Anal. Calcd. for CzlHesN03: C, 74.32; H , 7.42. Found: C, 74.43; H, 7.37. N-a-Methylbenzyl-N-(2-acetoxy-1-naphthylmethy1)acetamide was prepared from Mannich base by above procedure, 61% yield, m.p. 119-121", from methanol.Anal. Calcd. for CaH23NOa: C, 76.43; H , 6.41. Found: C, 76.30; H , 7.00. N-~Methylbenzyl-N-(2-hydroxy-1-naphthylmethy1)acetamide.-Hydrolysis of the above ester in 2% potassium hydroxide in 95% ethanol a t 25" for 3 hr. gave a product, m.p. 160-160.5", after two recrystallizations from 957@ ethanol.An exchange reaction occurs readilg between tertiary Mannich bases ( I ) and primary and secondary arylamines, making accessible the monosubstituted arylamine Mannich bases (I1 and IV) in good yield. The arylamines used include polycyclic and heterocvclic bases as well aa diamines. Experiments suggest that the overall amine-exchange reaction may proceed both by a substitution as well as by an eliminat...
Esters and amides derived from a@-acetylenic acids which do not possess a y-hydrogen atom undergo smooth cleavage with sodamide in liquid ammonia to give the terminal acetylenes in high yield. The free acids resist attack by sodamide. However, with ap-acetylenic acids having two yhydrogen atoms, there is rapid rearrangement to the a&-allenic acids. But-2-ynoic acid gives only buta-2,3-dienoic acid, but the C,-C, acids are substantially further transformed into their py-acetylenic isomers, and equilibrium mixtures containing 80-95% of the latter acids result. With ap-acetylenic amides having a y-methylene group, both fission to the terminal acetylene and rearrangement to the acetylenic amide occur.AN earlier communication2 reported the preparation of acetylenes ( 11) by reaction of a series of diethyl vinyl phosphates (I) with sodamide in liquid ammonia. For instance, diethyl trans-2-ethoxycarbonyl-l-phenylvinyl phosphate (Ia) gave phenylpropiolamide (72%) at -70". However, the same reactants at -33" afforded only phenylacetylene (75y0), isolated as the mercury salt; and phenylpropiolamide (formed by the action of anhydrous ammonia on ethyl propiolate) on treatment with sodamide in liquid ammonia at -33" was similarly completely transformed into phenylacetylene and urea (identified as dixanthhydrylurea 5). No phenylpropiolic acid was formed.
Arylthioureas, when heated in chlorobenzene at 150" for 5-10 hr., undergo fission to give good yields of aryl isothiocyanates containing 1, 2, 3, and 4 aromatic rings. The mechanism of the reaction has been investigated. METHODS of preparation of aryl isothiocyanates 1 include (a) the use of thiocarbonyl chloride or its precursor thiocarbonyl tetrachloride (the latter reaction fails with naplithj*l compounds 3), (b) acid-induced fission of an NN'-diarylthiourea, iiivolving the loss of 1 mol. of amine, and (c) decomposition of an ammonium aryldithi~carbamate,~ the last method giving low yields for naphthyl and other compound^.^It has now been found that arylthioureas, when heated in a suitable solvent at 150°, undergo fission into ammonia and the aryl isothiocyanate. No isothiocyanate was obtained on attempted vacuum-distillation of 4-diphenylyl-or a-naphthyl-thiourea without a solvent.the methods of de Clermont 8 and Bertram failed for the latter substance. N-4-Diphenylylthiourea was obtainable by either method, or from N-4-diphenylylammoniuni thiocyanate. The related N-4-diphenylyl-S-methylisothiourea, ammonium N-4-diphenylyldithiocarbamate, and N-Pdiphenylylguanidine were prepared, the last by heating N-4-diphen ylyldiguanide.When N-4-diphenylylthiourea was heated in solvents of various b. p.s, chlorobenzene gave optimum yields of N-4-diphenylyl isothiocyanate ; 1 : 2-dichlorobenzene also aff ordecl the desired product, though in smaller yield, while nitrobenzene or 1 : 2 : 4trichlorobenzene gave no isothiocyanate. N-4-Diphenylyl isothiocyanate had m. p. 63.5--64-5", though Desai, Hunter, and Kureishy lo claim m. p. 119-120".Brewster and Horner 11 claim preparation of this isothiocyanate by 3 hours' boiling of the "'-diary1 thiourea with acetic anhydride. This procedure in our hands gave NN-diacetyl-4-aminodipheny1, m. p. 118.5-11 9", and NN'-diacetyl-NN'-bis-4-diphenylylurea, hydrolysed by alkali to 4-acetamidodiphenyl. Reaction of acetic anhydride with the isothiocyanate afforded the same products. Werner l2 reported the action of acetic anhydride on NN'-diphenylthiourea to give phenyl isothiocyanate in 96,37,7, and 0% yield after 5,30,45, and 60 minutes' boiling respectively, but did not identify the product of decomposition. This isothiocyanate is known l3 to give the N-acylaniline and diphenylurea when treated with acetic or formic acid, while benzoic anhydride gives NN-diben~oylaniline.1~ The mechanism of isothiocyanate formation was investigated by using a-naphthylthiourea. The rate of evolution of ammonia a t 150°, measured during 6 hr., gave the results shown in the Figure . A plot of log,, CAo/(Cao -CNH,) (where CAo = initial concentration of thiourea and CNH, = concentration of ammonia at time t ) was linear only for 1.5 hr., although the " half-time " of the reaction (65 min.) was independent of the magnitude of Cbo. The possibility of the reaction's occurring in three successive steps (a), (b), and (c), with the intermediate formation of a dithiobiuret, could be dismissed in view of the failure of ...
E X P E R I M E N T A L WORKThe experimental equipment for the measurement of detonation velocities consisted of six different detonation tubes, a mixing and charging system, an ignition system, and a timing system.The characteristics of the detonation tubes are given in Table 1. The five round, straight tubes (A, B, C, D, and E ) were used to determine the effect of tube diameter on detonation velocity. Tube F was a 10-in. coil for convenience in temperature control for the high-and low-temperature experiments. The effect of coiling was evaluated by comparison of the velocities measured in tubes F and B. Rectangular tube G was used only to obtain schlieren photographs. All seven tubes were closed at both ends.The velocity of the detonation wave was measured with ionization probes. The probes were made by drilling a no. 76 drill through a Teflon insert in a stainless steel sleeve. The probes were threaded into the detonation tubes and adjusted so that the tip was flush with the wall. Each probe was connected as a shorting switch in the grid of an 884-thyratron tube. The grid bias of the thyratron tube was adjusted almost to the firing point to obtain maximum sensitivity. When the ionized gases behind the detonation front reached a probe, the resistance between the probe electrode (the drill) and ground (the tube wall) fell, and the thyratron fired. One probe and thyratron started a timer, and another probe and thyratron stopped it. The time interval was indicated to the nearest microsecond. The distances between the probes and the distance from the ignitor to the first probe are given in Table 1. The probe locations on tube F were on the outside of the coil and were determined before coiling. The distance between the probes was corrected for thermal expansion and contraction of the tube in computing the detonation velocity at nonambient temperatures. This correction was about 0.1% at the extreme temperatures. The starting distance for all the tubes was greater than the distance A.1.Ch.E. Journal indicated by LafEtte (14) and Greene (9) as necessary to attain stable detonation in hydrogen-oxygen mixtures. The probes required replacement after 20 to 30 runs.The high-temperature runs were made with the coiled tube in an oven, and the low-temperature runs with the coiled tube immersed in 5 gal. of normal propanol in an insulated tank. Dry ice was added to the propanol to cool to 200°K. and liquid nitrogen to reach lower temperatures. As the result of vigorous stirring, the temperature variation within the bath was held within rrfr2"K.The detonation tube was evacuated and then filled with premixed oxygen and hydrogen through a mapifold and switch system that kept the ignition circuit open while the filling valve was open. In the low-temperature runs the tube was evacuated at room temperature before cooling to avoid condensation. In both the highand low-temperature runs the mixture was not ignited until the pressure indicated on a manometer had remained constant for at least 5 min. Analyses of the hydrogen and oxygen o...
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.