Carboxymethylation, benzyl

Tetrahydro- lH-pyrazolo[ 1,2-fc]phthalazine-1,5-dione (327) underwent oxidative ring fission to give 2-[a-(carboxymethyl)benzyl]-l(2f0-phthalazi-none (328) (iV-bromosuccinimide, CCI4, °C, h 42% a mechanism was... 

The commercially available form of Aspartame is hemihydrate Form II, which transforms into hemihydrate Form I when milled, and a 2.5-hydrate species is also known [57,58]. XRPD has been used to study the desolvation and ultimate decomposition of the various hydrates. When heated to 150°C, both hemihydrate forms dehydrate into the same anhydrous phase, which then cyclizes into 3-(carboxymethyl)-6-benzyl-2, 5-dioxopiperazine if heated to 200°C. The 2.5-hydrate was shown to dehydrate into hemihydrate Form II when heated to 70°C, and this product was then shown to undergo the same decomposition sequence as directly crystallized hemihydrate Form II. 

Benzylation has been performed on wood in order to impart thermoplastic properties to the substrate (Hon and Ou, 1989). Wood is pre-treated with aqueous NaOH solution, then with benzyl chloride. Benzylation of the surfaces of wood blocks and chips for selfbonding of wood surfaces has also been reported (Kiguchi, 1990a,b Kiguchi and Yamamoto, 1992). A vapour-phase benzylation method has also been developed (Kiguchi, 1993). Carboxymethylation of NaOH-treated wood using various solvent systems has been studied (Shiraishi and Kishi, 1986 Honma and Nakano, 1991). Wood modified in this way has been used to make wood-phenolic adhesives (Kishi and Shiraishi, 1986). 

To further explore this phenomenon, we prepared a variety of base on alumina reagents. Their activity in the carboxymethylation of benzyl bromide is presented in Table IV. 

Table V. Carboxymethylation of Benzyl Bromide -Selectivity to Ester(a)...

At least three methods have been found to be applicable to the solubilization of chemically modified wood. The first experiment (4) (Direct method) employed severe dissolution conditions. For example, in 20-150 min at 200-250°C, wood samples esterified by a series of aliphatic acids could be dissolved in benzyl ether, styrene oxide, phenol, resorcinol, ben-zaldehyde, aqueous phenol solutions, etc. For carboxymethylated, ally-lated and hydroxyethylated woods, the conditions provided for dissolution in phenol, resorcinol or their aqueous solutions, formalin, etc., by standing or stirring at 170°C for 30 to 60 min (5). 

Scheme 2 Degradation pathways for aspartame APM = aspartame P-APM = P-aspartame PM = phenylalanine methyl ester DKP = 3-benzyl-6-carboxymethyl-2,5-diketopiperazine a-AP = a-L-aspartyl-Z,-phenylalanine PA = L-phenylalanyl-I-aspartic acid)...

R = CH2-C6H5 R2 = CH2-COOH Bis-[(benzyl-carboxymethyl-amino)-methyl]-phosphinsaure (als Hydro-... 

R1 = CH,-OH Rz = CH2-C6Hs R3 = CH r-COOH (100°) [(Benzyl-carboxymethyl-amino)-methyl]-hydro-... 

R = CCU R2 - CH,-C6Hs R3 = CH2-COOH (100°) l(Benzyl-carboxymethyl-amino)-methyl trichlorme-... 

Vollig analog werden aus Dichlor-methyl- und Dichlor-propyl-phosphan die entspre-chenden [(Benzyl-carboxymethyl-amino)-methyl]-methyl- (100%) bzw. -propyl-phos-phinsaure-Hydrochloride (83%) erhalten53. 

Butyloxy-propyl- XII/1, 257 Butyloxy-trimelhylsilyloxy- El, 339 tert.-Butyl-phenyl- El, 241, 244 tcrt.-Butyl-phcnyl-trifluoracetyl- E2, 8 (tti-Carboxy-alkyl)-diphenyl- E2, 52, 53 (a-Carboxy-bcnzyl)-diphenyl- E2, 34 (lO-Carboxy-decyl)-diphenyl- E2, 53 (2-Carboxy-ethyl)-diphenyl- Xll/1, 146 Carboxymethyl-diphcnyl- XII/1, 148 E2, 65, 66 (S-Carboxy-pentyl)-diphenyl- E2, 53 (3-Carboxy-phenyl)-diphenyl- XII/1, 143 El, 167 (4-Chlor-benzyl)-diphenyl- E2, 16, 18 (a-Chlor-benzyl)-diphenyl- E2, 11, 23 Chlorethinyl-diphenyl- E2, 23, 23 Chlor-ethoxy- El, 321 (2-Chlor-elhoxy)-ethyl- E2, 187 (2-Chlor-eihoxy)-hydroxy- XII/2, 11 Ammoniumsalz... 

Anilino-propyl)-methyl- E2, 143 (2-Arylaminocarbonyl-alkyl)-organo- E2, 140 (a-Bcnzylamino-benzyI)-ethyI- E2, 131 ( -Benzylamino-benzyl)-phenyl- E2, 131 (l-Benzylamino-eihyl)-phenyl- E2, 131 (l-Benzylamino-pentyl)-phenyl- E2, 131 Benzyl-butyl- -ethylester XII/1, 255 [(Bcnzyl-carboxymethyl-amino)-methyl]-ethyl- ... 

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