Chloro phosphonation

This difficulty was overcome by describing (I) as diethyl chloro phosphonate, and the use of this term was later endors by the... 

Compounds (71)- 73) are the potential products from the oxidative chloro-phosphonation of the alkenes (70) in practice, compounds (70a) and (70b) with PCI3/O2 yield mainly (71a) and (71b), respectively. The main difference between these examples and (70c) is that in this case the oxidative chlorophosphonation process is accompanied by the breakdown of the hydrocarbon chain. Although the main reaction pathway leads to... 

Triticale is a mnch lower input crop than winter wheat and some varieties of triticale can be qnite weak-strawed, particularly on less droughty soil. The growth regulators such as chlormequat, 2-chloro-phosphonic acid and trinexapac-ethyl will reduce lodging. 

A) The preparation of [H-chloroethoxyjchloromethyl]phosphonic acid Acetaldehyde (1.1 mol) and hydroxymethylphosphonlc acid (1 mol) in 500 ml of benzene are saturated with hydrogen chloride gas at 10°C to 15°C. The mixture is aged at 25°C for 24 hr, the solvent distilled out in vacuo and the residue flushed three times with benzene to remove all traces of hydrogen chloride. The residue is taken up in benzene (500 ml), treated with tert-butyl hypochlorite (0.8 mol) and azobisisobutyronitrile (0.8 mm) at 40°C until titration shows the absence of hypochlorite and the solution is then evaporated to yield [(1-chloro-ethoxy)chloromethyll phosphonic acid in the form of an oil. 

B) The preparation of (cis-1,2-epoxypropyi)phosphonic acid [ (1 -chloroethoxy )chloro-methyl] phosphonic acid (1.0 g) is added with stirring to tetrahydrofuran (50 ml) to which has been added a crystal of iodine and a zinc-copper couple (15.0 g). The mixture is then heated under reflux for 24 hr and the resulting solution filtered to yield (cis-1,2-epoxy propyl )-phosphonic acid. 

An aza-Darzens reaction, involving the addition of chloromethylphosphonate anions to enantiopure N-sulfinimines, has also been developed by Davis and others for the asymmetric synthesis of aziridine-2-phosphonates [81-84], As an example, treatment of the lithium anion generated from dimethyl chloromethylphos-phonate (93 Scheme 3.30) with N-sulfmimine (Ss)-92 gave the a-chloro-P-amino phosphonate 94, which could be isolated in 51% yield. Cyclization of 94 with n-BuLi gave cis-N-sulfmylaziridine-2-phosphonate 95 in 82% yield [81],... 

Photosensitive functions are in many cases also heat sensitive, so the preparation of photosensitive polyimides needs smooth conditions for the condensations and imidization reactions. Some chemical reactants, which can be used for polyamide preparation, have been patented for the synthesis of polyimides and polyimide precursors. For example, chemical imidization takes place at room temperature by using phosphonic derivative of a thiabenzothiazoline.102 A mixture of N -hydroxybenzotriazole and dicyclohexylcarbodiimide allows the room temperature condensation of diacid di(photosensitive) ester with a diamine.103 Dimethyl-2-chloro-imidazolinium chloride (Fig. 5.25) has been patented for the cyclization of a maleamic acid in toluene at 90°C.104 The chemistry of imidazolide has been recently investigated for the synthesis of polyimide precursor.105 As shown in Fig. 5.26, a secondary amine reacts with a dianhydride giving meta- and para-diamide diacid. The carbonyldiimidazole... 

Previous syntheses of terminal alkynes from aldehydes employed Wittig methodology with phosphonium ylides and phosphonates. 6 7 The DuPont procedure circumvents the use of phosphorus compounds by using lithiated dichloromethane as the source of the terminal carbon. The intermediate lithioalkyne 4 can be quenched with water to provide the terminal alkyne or with various electrophiles, as in the present case, to yield propargylic alcohols, alkynylsilanes, or internal alkynes. Enantioenriched terminal alkynylcarbinols can also be prepared from allylic alcohols by Sharpless epoxidation and subsequent basic elimination of the derived chloro- or bromomethyl epoxide (eq 5). A related method entails Sharpless asymmetric dihydroxylation of an allylic chloride and base treatment of the acetonide derivative.8 In these approaches the product and starting material contain the same number of carbons. 

A. Nucleophilic Reactions.—(/) Attack on Saturated Carbon. The Arbusov reaction has been used to prepare organosilicon-substituted phosphonates (1) and phosphorylated ethers (2a) and sulphides (2b). Bromo- and chloro-derivatives of the cyclic phosphite (3) do not react with ethyl halides... 

P. F. Tsytsymushkin, S. R. Khajmllin, A. P. Tamavskij, Z. N. Kudryashova, V. N. Levshin, B. V. Mikhajlov, Y. D. Morozov, and T. B. Kryukova. Plugging solution for oil and gas wells—contains plugging cement, nitrilo-trimethyl-phosphonic acid, product of reacting hexamethylene tetramine with chloro-derivatives unsaturated hydro-carbon(s) and water. Patent SU 1740629-A, 1992. 

In a similar way, numerous P-chloroalkylphosphonic acids undergo fast and quantitative hydrolysis at pH > 5 94). A typical example is the fragmentation of 2-chloro-decyl-l-phosphonic acid in the presence of cyclohexylamine with formation of 1-decene (in contrast, other bases such as pyridine, triethylamine, and dimethylaniline effect only HC1 elimination to form 1-decene-l-phosphonic acid). Added alcohols, such as ethanol, allyl alcohol, cyclohexanol, tert-butanol, and phenol are phosphorylat-ed. 

The O-alkyl O-silylphosphonates demonstrate the typical reactivity of phosphonates with a P-H bond. In silylation reactions with chloro silanes in presence of basis O-alkyl 0,0-disilylphosphonates can be synthesized. 

The 2,5-dihydro-l,2-oxaphosphole-2-oxide derivatives 196 were also obtained from the reaction of esters of 3-chloro-4-methyl-l,3-pentadiene-2-phosphonic acid with halogens (Scheme 78) [155, 156],... 

A novel chiral phosphonic amide-SiCl4 complex has also been found to serve as a catalyst for additions of allenyltributyltin to aldehydes (Table 9.45) [78], The reaction is limited to aromatic aldehydes because of competing formation of silylated chloro-hydrins from aliphatic aldehydes and the SiCI4 reagent. 

Nucleophilic Reactions.—Attack on Saturated Carbon. Selected examples of the Arbusov reaction include phosphorylation of the chloroacetophenones (1) to give phosphonates, which cyclized to (2) in the presence of acid chlorides,1 formation of the azodiphosphonate (3) from 2,2 -dichloro-2,2 -azopropane,2 3 and the reaction of 2-chloro-3,4-dihydro-3-oxo-2//-l,4-benzothiazine (4) with triethyl phosphite to give the 2-phosphonate (5), which is used as an olefin synthon.8 Bis(trimethylsilyl) trimethylsiloxymethylphosphonite (6) has been synthesized by silylation of hydroxy-methylphosphonous acid, and, as expected, undergoes a normal Arbusov reaction with alkyl halides to give the phosphonates (7).4 This series of reactions, followed by... 

Example 57 the synthesis of 2-chloro-iV -methyladenine-9-(2-methyl-propyl)bis phosphonate, analogous to the corresponding bisphosphate, has been performed by Jacobson and associates [93]. The key step in this synthesis is the Arbuzov-Michaelis reaction. 

Diethyl 2-chloro-2-cyclopropylethene-l,1-dicarboxylate, 66, 173, 174 Diethyl cyclopropylcarbonylmalonate (7394-16-3), 66, 175, 179 Diethyl cyclopropylmalonate, 66, 173 Diethyl dioxosuccinate (59743-08-7), 66, 144, 149 Diethyl isocyanomethylphosphonate Phosphonic acid, (isocyanomethyl)-, diethyl ester (41003-94-5), 65, 119 Diethyl malonate (105-53-3), 66, 175, 179... 

The light-induced addition elimination reaction of diethyl phosphite to both 1,3,3,4,4-penta-fluorocyclobutene and l-chloro-3,3,4,4-tetrafluorocyclobutene afforded a mixture of diethyl 3,3,4,4-letrafluorocyclobutene-l-phosphonate (11) and tetraethyl 3,3,4,4-tetrafluorocyclobutane-1,2-diphosphonate (12). The postulated mechanism of addition involves phosphonyl radical attack at the cyclobutene moiety.17... 

AMIDES Bis(o-nitrophenyl)phenyl-phosphonate. N,N-Bis(2-oxo-3-oxazoli-dinyl)phosphordiainidic chloride. 2-Chloro-2-oxo-l,3,2-bcnzodioxa-ph05-phole. Iodine azide. N-Methyl-N-phenyl-benzohydrazonyl bromide. Phase-transfer catalysts. N-Phenylseleno-phthalimidc. (SEProlinol. 

Phosphonate. Diethyl 2-Chloro-l-fluoro-eihene EI0b2. 153 (-CI, - En)... 

Phosphonate Diethyl 2-Chloro-2,2-difluoro-1 -hydroxy-1 -methyl-ethane ElOb. 681 [F2CIO-CO-R + H-PO(RO)2]... 

Phosphonate Diethyl 2-Chloro-l-cyclohcxyl-2.2-difluoro-l -hydroxy-ethane ElOb,. 681 [C1F,C — CO — R +... 

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