An Alternative Route to 2-Bromo-Estradiols and 2-Iodo-Estradiols From Estradiol

1987 ◽  
Vol 40 (2) ◽  
pp. 303 ◽  
Author(s):  
DJ Pert ◽  
DD Ridley
Keyword(s):  
Methyl Ether ◽  
Alternative Route ◽  
Reaction Conditions ◽  
Careful Choice ◽  
Ether Derivative ◽  
Trimethylsilyl Derivatives

Through careful choice of reaction conditions, alkylation of estradiol with chloromethyl methyl ether may yield either the 3,17β-bis(methoxymethy1) ether or the 3-methoxymethyl ether derivative. Treatment of either of these protected estradiols with s- butyllithium, then with trimethylsilyl chloride affords, regioselectively, the 2-trimethylsilyl derivatives which can conveniently be converted into 2-bromo-or 2-iodo-estradiol.

C-Formylation of Some 2(3H)-Benzazolones and 2H-1,4-Benzoxazin-3(4H)-one

1997 ◽  
Vol 62 (3) ◽  
pp. 494-497 ◽  
Author(s):  
Ognyan I. Petrov ◽  
Veneta B. Kalcheva ◽  
Antonina Ts. Antonova
Keyword(s):  
Methyl Ether ◽  
Trifluoroacetic Acid ◽  
Reaction Conditions

The C-formylation of 1,3-dimethyl-2(3H)-benzimidazolone and 4-methyl-2H-1,4-benzoxazin-3(4H)-one was performed using 1,1-dichloromethyl methyl ether at the Friedel-Crafts reaction conditions. The formylation of 3-methyl-2(3H)-benzoxa- and -thiazolone at the 6-position was carried out by modified Duff's method with hexamethylenetetramine in trifluoroacetic acid.

Reduction of N2 to NH3 Catalyzed by A Keggin-Type Polyoxometalate-Supported Dual-Atom Catalyst

2021 ◽  
Author(s):  
Yu Wang ◽  
Rui-Cheng Qin ◽  
Dan Wang ◽  
Chun-Guang Liu
Keyword(s):  
Alternative Route ◽  
Reaction Conditions ◽  
Bosch Process ◽  
Keggin Type ◽  
Dual Atom

Because of the harsh reaction conditions and relatively low NH3 yield of Haber-Bosch process for synthesized ammonia industry, it is highly desirable to develop an alternative route for more efficient...

scholarly journals Phosgene-free synthesis of 1,3-diphenylurea via catalyzed reductive carbonylation of nitrobenzene

2012 ◽  
Vol 84 (3) ◽  
pp. 473-484 ◽  
Author(s):  
Andrea Vavasori ◽  
Lucio Ronchin
Keyword(s):  
Phenyl Isocyanate ◽  
High Yield ◽  
Diphosphine Ligands ◽  
Alternative Route ◽  
Reaction Conditions ◽  
Bite Angle ◽  
Reductive Carbonylation ◽  
One Step ◽  
Optimum Reaction ◽  
Synthetic Intermediate

1,3-Diphenylurea (DPU) has been proposed as a synthetic intermediate for phosgene-free synthesis of methyl N-phenylcarbamate and phenyl isocyanate, which are easily obtained from the urea by reaction with methanol. Such an alternative route to synthesis of carbamates and isocyanates necessitates an improved phosgene-free synthesis of the corresponding urea. In this work, it is reported that Pd(II)-diphosphine catalyzed reductive carbonylation of nitrobenzene in acetic acid (AcOH)-methanol proceeds in high yield and selectivity as a one-step synthesis of DPU. We have found that the catalytic activity and selectivity of this process depends on solvent composition and on the bite angle of the diphosphine ligands. Under optimum reaction conditions, yields in excess of 90 molar % and near-quantitative selectivity can be achieved.

Catalyst-free Synthesis of Aminomethylphenol Derivatives in Cyclopentyl Methyl Ether via Petasis Borono-Mannich Reaction

2020 ◽  
Vol 17 ◽  
Author(s):  
Jia-Qi Di ◽  
Hao-Jie Wang ◽  
Zhen-Shui Cui ◽  
Jin-Yong Hu ◽  
Zhan-Hui Zhang
Keyword(s):  
Secondary Amine ◽  
Methyl Ether ◽  
Mannich Reaction ◽  
Phenylboronic Acid ◽  
Functional Materials ◽  
Practical Method ◽  
Model Reaction ◽  
Arylboronic Acid ◽  
Reaction Conditions ◽  
Catalyst Free

Objective: Aminomethylphenol molecules have wider applications in pharmaceuticals, agrochemicals, plant protection and promising functional materials. The development of an efficient and practical method to prepare this class of compound is highly desirable from both environmental and economical points of views. Materials and Methods: In order to establish an effective synthetic method for preparing aminomethylphenol derivatives, the Petasis borono-Mannich reaction of salicylaldehyde, phenylboronic acid and 1,2,3,4-tetrahydroisoquinoline was selected as a model reaction. A variety of reaction conditions are investigated including solvent and temperature. The generality and limitation of the established method were also evaluated. Results and Discussion: It was found that model reaction can be carried out in cyclopentyl methyl ether at 80 oC under catalyst-free condition. This protocol with a broad substrate applicability, the reaction of various arylboronic acid, secondary amine and salicylaldehyde proceeded smoothly under optimal reaction conditions to afforded various aminomethylphenol derivatives in high yields. A practical, scalable, and high-yielding synthesis of aminomethylphenol derivatives was successfully accomplished. Conclusion: A catalyst-free practical method for the synthesis of minomethylphenol derivatives based on Petasis borono– Mannich (PBM) reaction of various arylboronic acid, secondary amine and salicylaldehyde in cyclopentyl methyl ether has been developed. The salient features of this protocol are avoidance of any additive/catalyst and toxic organic solvents, use cyclopentyl methyl ether as the reaction medium, clean reaction profiles, easy operation, and high to excellent yield.

Verbindungen mit dem 1,3-Dimethyl-1,3-diaza-2-phosphetidin-4-on-Grundgerüst; Synthese von 1,3-Dimethyl-2-thia-1,3-diaza-2 λ4-phosphetidin-4-on-Derivaten / Compounds Involving the 1,3-Dimethyl-1,3-diaza-2-phosphetidine-4-one Structure; Synthesis of 1,3-Dimethyl-2-thia-1,3-diaza-2λ4-phosphetidine-4-one Derivatives

1990 ◽  
Vol 45 (10) ◽  
pp. 1398-1406 ◽  
Author(s):  
Johannes Breker ◽  
Ulrich Wermuth ◽  
Reinhard Schmutzler
Keyword(s):  
Elemental Sulphur ◽  
Alternative Route ◽  
Trimethylsilyl Derivative ◽  
Nmr Studies ◽  
Structure Synthesis ◽  
Elemental Analyses ◽  
Trimethylsilyl Derivatives ◽  
New Compounds

In the reaction with hexamethyldisilthiane the cyclic trichlorophosphorane O=C(NMe)2PCl3 (1) was converted to the new compound O=C(NMe)2P(=S)Cl (2). A range of derivatives, O=C(NMe)2P(=S)Y (Y=NR2, OMe, SMe, 3-7) was obtained in the reaction of 2 with the appropriate trimethylsilyl derivatives, Me3SiY. The compounds 8 and 9 (Y=NPh2 and N(C6H11)2) could not be synthesized by this route as the required trimethylsilyl derivative was not reactive enough (Me3SiNPh2) or was not available (Me3SiN(C6H11)2), presumably on account of the bulk of the NPh2 and N(C6H11)2 groups. 8 and 9 could be prepared by an alternative route, i. e. by addition of elemental sulphur to the λ3P-diazaphosphetidinones, O=C(NMe)2PNR2 (R=Ph, C6H11), 10 and 11. Identity and structure of the new compounds were established on the basis of their elemental analyses and 1H, 13C and 31P NMR studies

Medium-sized cyclophanes. Part 62:1 Formylation of anti-[n.2]metacyclophanes — Through-space electronic interactions between two benzene rings

2003 ◽  
Vol 81 (3) ◽  
pp. 244-252 ◽  
Author(s):  
Takehiko Yamato ◽  
Tsuyoshi Furukawa ◽  
Kan Tanaka ◽  
Tsutomu Ishi-i ◽  
Masashi Tashiro
Keyword(s):  
Methyl Ether ◽  
Electrophilic Aromatic Substitution ◽  
Similar Reaction ◽  
Reaction Conditions ◽  
Ring Inversion ◽  
Electronic Interactions ◽  
Strained Molecules ◽  
Tert Butyl ◽  
Butyl Group ◽  
Tert Butyl Group

Formylation of anti-[n.2]metacyclophanes (1) (n = 2, 3, 4) with dichloromethyl methyl ether in the presence of TiCl4 occurred selectively at para-position to the internal methyl substituents of anti-[n.2]metacyclophanes. Similar reaction of anti-5,13-di-tert-butyl-8,16-dimethyl[2.2]metacyclophane (6a) with dichloromethyl methyl ether in the presence of TiCl4 led to ipso-formylation at the tert-butyl group to give anti-5-tert-butyl-13-formyl-8,16-dimethyl[2.2]-meta cyclophane (7a) as well as the corresponding 2,7-di-tert-butyl-trans-10b,10c-dimethyl-10b,10c-dihydropyrene (10), anti-5-tert-butyl-8,16-dimethyl-13-(3-methyl-1-butene-2-yl)[2.2]metacyclophane (8), and anti-5,13-di-tert-butyl-exo-1-hydroxy-8,16-dimethyl[2.2]metacyclophane (9) depending on the reaction conditions. The higher yield of ipso-formylated product is obtained in the presence of AlCl3 MeNO2 in 80% yield along with anti-5-tert-butyl-8,16-dimethyl-13-(3-methyl-1-butene-2-yl)[2.2]metacyclophane (13). Thus, the yield of ipso-formylation at the tert-butyl group of 6a was strongly affected by the activity of the formylation catalyst. Interestingly, in the formylation of anti-6,14-di-tert-butyl-9,17-dimethyl[3.2]metacyclophane (6b) under the same reaction conditions, syn-6,14-di-tert-butyl-7-formyl-9,17-dimethyl[3.2]metacyclophane (14b) was obtained in 40% yield arising from the anti-syn-ring inversion of the formylation intermediate along with ipso-formylation product 7b in 42% yield. In the formylation of anti-[4.2] meta cyclophane (6c) only the mono-ipso-formylated product 7c was obtained in 92% yield. The formation of a two-fold ipso-formation product, i.e., anti-5,13-diformyl-8,16-dimethyl[2.2]metacyclophane (3a), was not observed under the reaction conditions used. The mechanism of the ipso-formation as well as the formation of the present novel reaction products 8 and 9 is also discussed. Key words: cyclophanes, strained molecules, electrophilic aromatic substitution, ipso-formylation, σ-complex intermediates, through-space electronic interactions.

A revision of the structures proposed for the melicope extractives, melicopol and methylmelicopol

1973 ◽  
Vol 26 (11) ◽  
pp. 2459 ◽  
Author(s):  
BS Balgir ◽  
LN Mander ◽  
STK Mander
Keyword(s):  
Methyl Ether ◽  
Partial Methylation ◽  
Ether Derivative

2,4,6-Trihydroxybenzoic acid was converted by partial methylation, formylation, and then reduction into methyl 2-hydroxy-3-hydroxymethyl- 4,6-dimethoxybenzoate (5) which proved different from dimethyldegeranylmelicopol. Methyl 6-geranyloxy-2-hydroxy-3- hydroxymethyl-4-methoxybenzoate (4), its neryl analogue (7), and methyl 4-geranyloxy-2-hydroxy-3-hydroxymethyl-6-methoxybenzoate (21) were prepared similarly but all were different from methylmelicopol. From a re-investigation of earlier work, melicopol and methylmelicopol were assigned new structures, 6?-geranyloxy-2,2?,4?-tri-hydroxy-3?- methoxyacetophenone (31) and its 4?-methyl ether derivative (24), respectively. Dimethyldegeranylmelicopol, 2,6?-dihydroxy-2?,3?,4?- trimethoxyacetophenone (25), was prepared from antiarol (28) and acetoxyacetonitrile.

The preparation and photolysis of (E)-1-Aryl-3-methyl-3-phenylbut-1-enes

1983 ◽  
Vol 36 (3) ◽  
pp. 565 ◽  
Author(s):  
JW Blunt ◽  
JM Coxon ◽  
WT Robinson ◽  
HA Schuyt
Keyword(s):  
Reaction Time ◽  
Benzyl Alcohol ◽  
Sulfonic Acid ◽  
Reaction Times ◽  
Grignard Reaction ◽  
Aryl Substituent ◽  
Reaction Conditions ◽  
Careful Choice ◽  
Short Reaction Time ◽  
Toluene Sulfonic Acid

Reaction of 2-methyl-2-phenylpropylmagnesium chloride with benzaldehyde in tetrahydrofuran gave 2,7-dimethyl-2,4,5,7-tetraphenyloctane-4,5-diol as a 1 : 2 mixture of clear transparent crystalline plates (meso) and needles (�), 3-methyl-1,3-diphenylbutan-1-one, benzyl alcohol, 2-methyl-2-phenylpropaneand a low yield of 3-methyl-1,3-diphenylbutan-1-ol. The distinction between the meso and the (+)- diols was unequivocal because the unique space group of the former requires thedimeric molecules to lie about a crystallographic centre of symmetry. The mechanism involved in the formation of the products of the Grignard reaction is examined. By careful choice of reaction conditions a series of I-aryl-3-methyl-3-phenylbutan-1-ols were prepared. Dehydration of the 1-aryl-3-methyl-3-phenylbutan-1-ols with p-toluene sulfonic acid and a short reaction time gives(E)-1-aryl-3-methyl-3-phenylbut-1-enes but longer reaction times afford 3-aryl-1,1-dimethylindanes.Photolysis of the (E)-1-aryl-3-methyl-3-phenylbut-1-enes affords (Z)-1-aryl-3-methyl-3-phenylbut-1-enes and trans-1-aryl-3,3-dimethyl-2-phenylcyclopropanes. Extended photolysis gives 4-aryl-2-methyl-3-phenylbut-1-enes via trans-1-aryl-3,3-dimethyl-2-phenylcyclopropane by rupture of the cyclopropyl bond adjacent to the aryl substituent.

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