Glycine preparation

The derivative of glycine, prepared from benzophenone (cat. BF3 Et20, xylene, reflux, 82% yield), has found considerable use in the preparation of amino acids. It can also be prepared by an exchange reaction with benzophenoneimine (Ph2C=NH, CH2CI2, rt). ... 

Fig. 15. The configurational assignment of (S)-[2- H]glycine prepared from serine using SHMT.

Fig. 16. Configurational analysis of enantiomeric glycines prepared via an exchange reaction catalysed by SHMT.

Reaction with Aldehyde. Reaction of aldehydes (prim-, sec-, and ferf-) with the dlazoacetamlde of TV-substituted glycinate, prepared from the amino ester and (1), affords /3-keto amides in good to high yields in the presence of Zr(IV) chloride in CH2CI2. Further treatment with / -Bu4NF in THF leads to A(-protected 3-acyltetramlc acids (eq 13). ... 

One-step proeess. A soln. of benzyl p-nitrophenyl carbonate in dioxane added to aq. Na-glycinate (prepared from glycine and NaHGOg) heated 3 hrs. at 100°, 1 N HGl added in the cold followed by a soln. of dicyclohexylcarbodiimide in dioxane, kept 0.5 hr. in an ice-bath, and 2 hrs. at room temp. benzyloxy-carbonylglycine p-nitrophenyl ester. Y 78%. F. e. s. Y. Wolman, D. Ladkany, and M. Frankel, Soc. (G) 1967, 689 with ferf-butyl 2,4,5-trichlorophenyl carbonate, co-extraction of the intermediates, cf. W. Broadbent, J. S. Morley, and B. E. Stone, Soc. (G) 1967, 2632 with ferf-butyl pentachlorophenyl carbonate cf. M. Fujino and G. Hatanaka, Ghem. Pharm. Bull. 15, 2015 (1967). 

Glycine is the simplest member of a large and very important class of compounds, the a-amino-carboxylic acids. TTiere are many different methods available for the synthesis of amino-acids, but glycine can be readily prepared by the action of an excess of ammonia on chloroacetic acid ... 

Dinitrobenzoyl-glycine. Dissolve 0 4 g. of glycine in 10 ml. of TV.NaOH solution in a small stoppered bottle. And i-i g. of finely powdered 3 5-dinitrobenzoyl chloride (preparation, p. 242) and shake vigorously for about 1 minute. Filter if necessary and acidify with dil. 

Simple esters cannot be allylated with allyl acetates, but the Schiff base 109 derived from o -amino acid esters such as glycine or alanine is allylated with allyl acetate. In this way. the o-allyl-a-amino acid 110 can be prepared after hydrolysis[34]. The Q-allyl-o-aminophosphonate 112 is prepared by allylation of the Schiff base 111 of diethyl aminomethylphosphonates. [35,36]. Asymmetric synthesis in this reaction using the (+ )-A, jV-dicyclohex-ylsulfamoylisobornyl alcohol ester of glycine and DIOP as a chiral ligand achieved 99% ec[72]. 

Pharmaceuticals. -Hydroxybenzaldehyde is often a convenient intermediate in the manufacture of pharmaceuticals (qv). For example, 2-(p-hydroxyphenyl)glycine can be prepared in a two-step synthesis starting with -hydroxybenzaldehyde (86). This amino acid is an important commercial intermediate in the preparation of the semisynthetic penicillin, amoxicillin (see ANTIBIOTICS, P-LACTAMs). Many cephalosporin-type antibiotics can be made by this route as well (87). The antiemetic trimethobenzamide [138-56-7] is convenientiy prepared from -hydroxybenzaldehyde (88) (see Gastrointestinal agents). 

A Methylamino)phenol. This derivative, also named 4-hydroxy-/V-methy1ani1ine (19), forms needles from benzene which are slightly soluble in ethanol andinsoluble in diethyl ether. Industrial synthesis involves decarboxylation of A/-(4-hydroxyphenyl)glycine [122-87-2] at elevated temperature in such solvents as chlorobenzene—cyclohexanone (184,185). It also can be prepared by the methylation of 4-aminophenol, or from methylamiae [74-89-5] by heating with 4-chlorophenol [106-48-9] and copper sulfate at 135°C in aqueous solution, or with hydroquinone [123-31 -9] 2l. 200—250°C in alcohoHc solution (186). 

A/-(4-Hydroxyphenyl)glycine can be prepared from 4-aminophenol and chloracetic acid (199,200) or by alkaline hydrolysis of the corresponding nitrile with subsequent elimination of ammonia (201). 

Catalytic amounts of mercuric chloride are usually employed in this preparation. Aluminum isopropoxide is a useful Meerwein-Potmdorf-Verley reducing agent in certain ester-exchange reactions and is a precursor for aluminum glycinate, a buffering agent (see Alkoxides, metal). 

Alternatively, various 4-substituted derivatives have been prepared via synthesis of amino acid (68) by reaction of the anion formed from protected glycine and an appropriately substituted Schiff base. 

Most pteridines are degraded to pyrazines and when they do yield pyrimidines, these may well be the ones from which they were made. However, some useful preparations of pyrimidines from pteridines are known. Thus, reduction of pteridin-7(8//)-one (732) and subsequent hydrolysis yields N-(4-aminopyrimidin-5-yl)glycine (733) (52JCS1620) and hydrolysis of 5,8-dimethylpteridine-6,7(5Ff,8Ff)-dione (734) gives dimethyl-... 

Glycine ethyl ester hydrochloride has been prepared by the action of absolute alcohol and hydrogen chloride on glycine from glycyl chloride and alcohol by the action of ammonia or hexamethylenetetramine on chloroacetic acid, and subsequent hydrolysis with alcoholic hydrochloric acid and by the action of hydrogen chloride and alcohol on methyleneamino-acetonitrile. ... 

This chapter lists some representative examples of biochemicals and their origins, a brief indication of key techniques used in their purification, and literature references where further details may be found. Simpler low molecular weight compounds, particularly those that may have been prepared by chemical syntheses, e.g. acetic acid, glycine, will be found in Chapter 4. Only a small number of enzymes and proteins are included because of space limitations. The purification of some of the ones that have been included has been described only briefly. The reader is referred to comprehensive texts such as the Methods Enzymol (Academic Press) series which currently runs to more than 344 volumes and The Enzymes (3rd Edn, Academic Press) which runs to 22 volumes for methods of preparation and purification of proteins and enzymes. Leading referenees on proteins will be found in Advances in Protein Chemistry (59 volumes. Academic Press) and on enzymes will be found in Advances in Enzymology (72 volumes, then became Advances in Enzymology and Related Area of Molecular Biology, J Wiley Sons). The Annual Review of Biochemistry (Annual Review Inc. Patio Alto California) also is an excellent source of key references to the up-to-date information on known and new natural compounds, from small molecules, e.g. enzyme cofactors to proteins and nucleic acids. 

There are no reported examples of imsaturated 2,2 -bis-oxazolones (11), although it is likely that they could be prepared from aldehydes and W,W -diacylbis-glycines. 

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