4312-87-2

Usage

Preparation

(a) Preparation of hydroxylamine solution. Thirty grams (0.43 mole) of hydroxylamine hydrochloride is dissolved in 150 ml of boiling methanol. The solution is cooled somewhat and a solution of 9.9 gm (0.43 gm-atom) of sodium in 150 ml of methanol is added cautiously. The mixture is cooled and then placed in an ice-salt bath until the sodium chloride formed has been precipitated as completely as possible. After the sodium chloride has been filtered off, approximately 200 ml of the methanol is distilled off under reduced pressure. The still residue is again filtered and then used directly in the next step. (b) Preparation of formohydroxamic acid. The hydroxylamine solu-tion, prepared as above, is cooled at 0°C. Then 31 gm (0.42 mole) of ethyl formate is added. During this addition an increase in temperature is observed. This is moderated by cooling in a stream of running water. After the addition has been completed, the reaction mixture is allowed to stand at room temperature for several hours. The excess methanol is evaporated from the reaction mixture under reduced pressure. The crystalline residue is contaminated with a small amount of an oily substance and some sodium chloride. The oily material is removed by pressing the crude product on an unglazed clay plate. The yield is 17.9 gm (70%). The product is crystallized from ethyl acetate. During this process, the remaining sodium chloride is separated by filtra-tion of the hot solution. The final product melts at 81-82°C.

InChI:InChI=1/CH3NO2/c3-1-2-4/h1,4H,(H,2,3)

Upstream product

• 203861-67-0 N-methyl-4-tolylnitrone 
• 93-61-8 N-methyl-N-phenylformamide 
• 7707-64-4 3-phenyl-furazan 5-oxide 
• 7732-18-5 water 
• 188686-50-2 metafulminuric acid 
• 74-89-5 methylamine 
• 79-02-7 2,2-dichloroacetaldehyde 
• 7803-49-8 hydroxylamine 
• 97925-87-6 2,2,2-trichloro-1-hydroxyamino-ethanol 
• 7647-01-0 hydrogenchloride 
• 75-52-5 nitromethane 
• 27064-04-6 S-(4-nitrophenyl) thioformate 

Downstream Products

• 64-18-6 formic acid 
• 93-61-8 N-methyl-N-phenylformamide 
• 10544-72-6 dinitrogen tetraoxide 
• 15719-64-9 methylammonium carbonate 
• 611-15-4 1-methyl-2-vinyl-benzene 
• 255705-14-7 O-trimethylsilylformohydroxamic acid 
• 7803-49-8 hydroxylamine 

Relevant academic research and scientific papers

Dissection of Nucleophilic and General Base Roles for the Reaction of Phosphate with p-Nitrophenyl Thiolacetate, p-Nitrophenyl Thiolformate, and Phenyl Thiolacetate

Phosphate buffers are well-known to catalyze the decomposition of various active acyl compounds. This study was undertaken to determine the extent to which it acts as a nucleophile and general base toward some activated esters and thiolesters. Thus, the hydrolyses of p-nitrophenyl acetate (3a), p-nitrophenyl thiolacetate (3b), phenyl acetate (4a), phenyl thiolacetate (4b), and p-nitrophenyl thiolformate (5) have been studied in aqueous phosphate, μ = 1.0 (K2SO4). Both phosphate monoanion and dianion are reactive toward the thiolesters 3b, 4b, and 5. For 3b, reaction of the dianion exhibits a solvent kinetic isotope effect (SKIE) of 1.00 ± 0.11 while that for the monoanion is 2.13 plusmn; 1.1. For the reaction of phosphate dianion with 5, the SKIE is 0.8 ± 0.2 and that for the monoanion at pH 3.05 is roughly 1.5. Phosphate dianion reacts with each thiolacetate and its oxygen analogue at comparable rates: the reactivity ratio of the formyl to acetyl thiolesters, 5:3b, toward phosphate dianion is 685. 1H NMR analysis of the 3b hydrolysis mixtures in H2O and D2O containing phosphate shows the transient formation, and subsequent hydrolysis, of acetyl phosphate. Analysis of the kinetics of these processes indicates that in H2O at pH = 8.5, phosphate dianion functions as both a nucleophile and general base toward 3b, the nucleophilic role comprising 80-93% of the reaction. In D2O, the process is entirely nucleophilic. For the reaction of phosphate dianion with 4b, the 1H NMR analysis indicates that the nucleophilic role comprises 40-50% of the reaction, the general base role being 50-60%. The reaction of phosphate dianion with 5 is entirely nucleophilic, while the monoanion reacts as a general base. The data are interpreted in terms of standard carbonyl addition/elimination mechanisms in which the ability of the attacking phosphate di- or monoanion to displace a given leaving group is tied to the pKa of the conjugate acids of the nucleophile and leaving groups.

The tetrahedral intermediate from the hydration of N-methylformanilide

Heats of hydrolysis of N-methylformanilide dimethyl acetal have been measured in basic solution.The heat of formation of N-methylformanilide was obtained by determining the equilibrium constant in aqueous solution for its formation from formic acid and N-methylaniline as a function of temperature: ΔH0f(l) = -33.78 +/- 1.85 kcal/mol.These data permit the calculation of the heat of formation of N-methylformanilide dimethyl acetal, ΔH0f(l) = -72.95 +/- 1.85 kcal/mol.The free energy of formation of the tetrahedral intermediate in the hydrolysis of N-methylformanilide was calculated by methods we have previously reported.Consideration of the energetics of the intermediates and the known rates of reaction leads to the conclusion that the rate-determining step for alkaline hydrolysis is cleavage of the C-N bond.