Methoxymethyl chloride

Treatment of 8-azidomethylperhydropyrido[l,2-c]pyrimidin-l-one 157 with methyl triflate and catalytic hydrogenation of the azide group led to the formation of tricyclic guanidine derivative 158 (01JA8851). Hydroxy group of 149 was protected with methoxymethyl chloride, and the p-methoxybenzyl protecting group (PMB) was eliminated by treatment with DDQ. 

The methoxymethyl (MOM) and (3-methoxyethoxymethyl (MEM) groups are used to protect alcohols and phenols as formaldehyde acetals. These groups are normally introduced by reaction of an alkali metal salt of the alcohol with methoxymethyl chloride or (3-methoxyethoxymethyl chloride.157... 

The synthesis of the second Stille coupling partner 34 was efficiently achieved in three steps. First, 2-bromojuglone (36) [28] was protected as its methoxymethyl ether (46, Scheme 3.7). The quinone was reduced using sodium thiosulfate, and the resulting hydroquinone was protected with methoxymethyl chloride to afford the arene 47. Finally, stannylation using tetrakis-(triphenylphosphine)palladium and hexabutylditin [29] afforded the cross-coupling partner 34 in high yield. 

The procedure was proved to be general for the preparation of protected hydroxy acids from lactones (121). This apparently trivial process is often difficult to carry out, as the attempted derivatization of y or J-hydroxyacids frequently results in relactonization rather than hydroxyl protection. The method was applied to several aldonolactones to produce the corresponding intermediate hydroxyamides. Protection using [(2-trimethylsilyl)-ethoxy]methyl chloride, methoxymethyl chloride, ter/-butylchlorodimeth-ylsilane, or zm-butylchlorodiphenylsilane followed by ozonolysis gave the protected N-(y- or <5-hydroxyacyl)indole derivatives. Mild saponification gave indole and the acetal- or silyl-protected hydroxy acids. 

The potassium salt of (3,4-difluorophenylamino)mercaptometh-ylenemalonate (342, R = F, X = K) was reacted with methoxymethyl chloride in dioxane at room temperature for 3 hr to afford diethyl (3,4-difluorophenylamino)(methoxymethylthio)methylenemalonate (343) in good yield (87BRP2190376). 

Carbonylation 1,4-diazepines.1 A key step in the synthesis of the antitumor agents neothramycin A and B (3) is the Pd(0)-catalyzed carbonylation of 1, prepared by condensation of 2-bromo-4-methoxy-5-tosyloxyaniline with N,0-bistrifluoroac-etyl-4-hydroxyproline followed by deprotection and protection with methoxymethyl chloride. The reaction provides the 1,4-diazepine 2, which can be converted into a mixture of 3A and 3B. 

Ac, acetyl AIBN, azobis(isobutanonitrile) All, allyl AR, aryl Bn, benzyl f-BOC, ferf-butoxycarbonyl Bu, Butyl Bz, benzoyl CAN, ceric ammonium nitrate Cbz, benzyloxycarbonyl m-CPBA, m-chloroperoxybenzoic acid DAST, diethylaminosulfur trifluoride DBU, l,8-diazabicyclo[5.4.0]undec-7-ene DCC, /V. /V - d i eye I oh e x y I c ar bo -diimide DCM, dichloromethyl DCMME, dichloromethyl methyl ether DDQ, 2,3-dichloro-5,6-dicyano-l,4-benzoquinone DEAD, diethyl azodicarboxylate l-(+)-DET, L-(+)-diethyl tartrate l-DIPT, L-diisopropyl tartrate d-DIPT, D-diisopropyl tartrate DMAP, 4-dimethylaminopyridine DME, 1,2-dimethoxyethane DMF, /V./V-dimethylformamide DMP, 2,2-dimethoxypropane Et, ethyl Im, imidazole KHMDS, potassium hexamethyldisilazane Me, methyl Me2SO, dimethyl sulfoxide MOM, methoxymethyl MOMC1, methoxymethyl chloride Ms, methylsulfonyl MS, molecular sieves NBS, N-bromosuccinimide NIS, /V-iodosuccinimide NMO, /V-methylmorpho-line N-oxide PCC, pyridinium chlorochromate Ph, phenyl PMB, / -methoxvbenzyl PPTs, pyridiniump-toluenesulfonate i-Pr, isopropyl Py, pyridine rt, room temperature TBAF, tetrabutylammonium fluoride TBS, ferf-butyl dimethylsilyl TBDMSC1, f-butylchlorodimethylsilane Tf, trifhioromethylsulfonyl Tf20, trifluoromethylsulfonic anhydride TFA, trifluoroacetic acid THF, tetrahydrofuran TMS, trimethylsilyl TPAP, tetra-n-propylammonium perruthenate / -TsOH. / -toluenesulfonic acid... 

Hatakeyama [6] reduced the number of alcohol groups by approximately 50% in perfluoro terpmonomer resists to modify surface adhesion and transparency by postreacting with methoxymethyl chloride. 

The reaction with halides such as methyl iodide, allyl bromide, benzyl bromide, bromomethyl acetate, or methoxymethyl chloride, to give the C-alkylated product, can be carried out in HMPT or without solvent.114... 

The Sn-0 bond in the alkylperoxytin compounds will in all probability show the same substitution and addition reactions as it does in alkoxytin compounds, but few studies of these reactions have been reported. In the air, hydrolysis occurs, and the stannyl peroxides, ROOSnBu3, have been shown to react with electrophiles such as triphenylmethyl chloride, methoxymethyl chloride, t-butyldimethylsilyl triflate, and acyl halides or acid anhydrides to give the peroxides R00CPh3, ROOCH OMe, ROOSiMeaBu1, and ROOCOR, respectively. 137-146... 

Activated acidic alumina has been described in a procedure to protect alcohols with methoxymethyl chloride using ultrasound as a non-classical way of activation [Eq. (17)1 [33]. 

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