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Purification of Organic Chemicals

Furfuryl alcohol [98-00-01 M 98.1, b 68-69O/20mm, 170.0°/750mm, d 1.132, n 1.4873, n30 1.4801. Distd under reduced pressure to remove tarry material, shaken with aqueous NaHCO3, dried with Na2S04 and fractionally distd under reduced pressure from Na2C03. Further dried by shaking with Linde 5A molecular sieves. Furfuryl amine [617-89-01 M 97.1, b 142.5-143°/735mm, d 1.059, n 1.489. nitrogen from KOH through a column packed with glass helices.

Distd under

Furil [492-94-41 M 190.2, m 165-166O. Crystd from MeOH or benzene (charcoal). 2-Furoic acid see furan-2-carboxylic acid. Furoin [552-86-31 M 192.2, m 135-136O. Crystd from MeOH (charcoal). Furylacrylic acid see 2-furanacrylic acid.

Galactaric Acid

(mucic acid) [526-99-61 M 210.1, m 212-213O(dec). Dissolved in the minimum volume of dil aq NaOH, and ppted by adding dil HCl. The temperature should be kept below 2 5 O . D-Galactonic acid

[576-36-31 M 196.2, m 148O. Crystd from EtOH.

D(-)-Galactono-1,4-lactone [2782-07-21 M 178.1, m 134-137O, [a];' from EtOH.

-78O (in H2O). Crystd

D(+)-Galactosamine hydrochloride [ I 772-03-81 M 215.6, m 181-18S0, [a]: +96.4O ( a f t e r 24h, c 3.2 in H20). Dissolved in a small volume of H20. Then added three volumes of EtOH, followed by acetone until faintly turbid and stood overnight in a refrigerator. [Roseman and Ludoweig JACS 76 301 19541. a-D-Galactose [59-23-41 M 180.2, m 167-168O, [a];' +80.4O (after 24h, c 4 in H 2 0 ) . Crystd twice from aqueous 80% EtOH at -100, then dried under vacuum over P205. Gallic acid (H20) Genistein Genistin

[149-91-71 M 188.1, m 253O(dec). Crystd from water.

[446-72-01 M 270.2, m 297-298O. Crystd from 60% aqueous EtOH or water. [529-59-91 M 432.4, m 256O. Crystd from 80% EtOWwater.

a-Gentiobiose

[Z6750-26-81 M 342.3, m 86O. Crystd from MeOH (retains solvent of crystn).

P-Gentiobiose

[554-91-61 M 342.3, m 190-195O. Crystd from EtOH.

Geraniol [106-24-11 M 154.3, b 230°, d 0.879, n 1.4766. Purified by ascending chromatography or by thin layer chromatography on plates of kieselguhr G with acetone/water/liquid paraffin (130:70:1) as solvent system. Hexane/ethyl acetate ( 1 :4) is also suitable. Also purified by GLC on a silicone-treated column of Carbowax 20M (10%) on Chromosorb W (60-80 mesh). [Porter PAC 20 499 19691. Stored in full, tightly sealed containers in the cool, protected from light. Geranylgeranyl pyrophosphate [6699-20-31 M 450.5. Purified by counter-current distribution between two phases of a butanol/isopropyl ethedammonia /water mixture ( 1 5 5 : 1:19) (v/v), or by chromatography on DEAE-cellulose (linear gradient of 0.02M KCl in 1mM Tris buffer, pH 8.9). Stored as a powderat 00.

228

Purification of Organic Chemicals

Geranyl pyrophosphate [763-10-01 M 314.2. Purified by paper chromatography on Whatman No 3 MM paper in a system of isopropyl alcohol/isobutyl alcohoVammonidwater (40:20: 1:39), RF 0.77-0.82. Stored in the dark as the ammonium salt at Oo. Gibberillic acid from ethyl acetate. Girard Reagent T Glucamine

[77-06-51 M 346.4, m 233-23S0(dec), [a]25046+92O (c 1, MeOH).

Crystd

[123-46-61 M 167.6, m 192O. Crystd from absolute EtOH.

[488-43-71 M 181.2, m 127O. Crystd from MeOH.

D-Gluconamide

[3118-85-2] M 197.2, m 144O, [a];3 +31° (c 2, HzO). Crystd from EtOH.

D-Glucono-6-lactone [90-80-21 M 178.1, m 152-153O, [a]::, +76O (c 4, H2O). Crystd from ethylene glycol monomethyl ether and dried for lh at 1 loo. Glucosamine

[3416-24-81 M 179.2, m llOO(dec). Crystd from MeOH.

D-Glucosamine hydrochloride [66-84-21 M 215.6, m >300°, [a];' +71.8O (after 20h, c 4, H20). Crystd from 3M HCI, water, and finally waterEtOWacetone as for galactosamine hydrochloride. a-D-Glucose [492-62-61 M 180.2, m 146O, [a]k0+52.S0 (after 24h, c 4, HzO). Recrysts slowly from aqueous 80% EtOH, then vacuum dried over P2O5. Alternatively, crystd from water at 5 5 O , then dried for 6h in a vacuum oven between 60-70° at 2mm. P-D-Glucose

[50-99-71 M 180.2, m 148-150°. Crystd from hot glacial acetic acid.

a-D-Glucose pentaacetate [604-68-21 M 390.4, m 110-11lo, [a]20+119O (c 5, CHCI3), 546 2 o P-D-Glucose pentaacetate [604-69-31 M 390.4, m 131-132O, [ a ] 5 4 +6S o (c 5, CHC13). Crystd from MeOH or EtOH. D-Glucose phenylhydrazone

[534-97-41 M 358.4, m 208O.

Crystd from aqueous EtOH.

Glucose-l-phosphate [59-56-31 M 260.1. Two litres of 5% aq soln was brought to pH 3.5 with glacial acetic acid (+ 3g of charcoal, and filtered). An equal volume of EtOH was added, the pH was adjusted to 8.0 (glass electrode) and the soln was stored at 3O overnight. The ppte was filtered off, dissolved in 1.2L of distd water, filtered and an equal volume of EtOH was added. After standing at Oo overnight, the crystals were collected at the centrifuge, and washed with 95% EtOH, then absolute EtOH, ethanovethyl ether (1:l), and ethyl ether. [Sutherland and Wosilait, JBC 218 459 19561. Its barium salt can be crystd from water and EtOH. Heavy metal impurities can be removed by passage of an aqueous soln (ca 1%) through an Amberlite IR-120 column (in the appropriate H+, Na+ or K+ forms). Glucose-6-phosphate [sodium salt 54010-71-81 M 260.1. Can be freed from metal impurities as described for glucose-l-phosphate. Its barium salt can be purified by solution in dilute HCl and pptn by neutralising the soln. The ppte is washed with small volumes of cold water and dried in air. D-Glucuronic acid or ethyl acetate.

[6556-12-31 M 194.1, m 16S0, [(XI?

+36O (c 3, H20). Crystd from EtOH

D-Glucuronolactone [32449-92-61 M 176.1, m 175-177O, [a]25046+22O (after 24h, c 10, HzO). Crystd from water. L-Glutamic acid [56-86-01 M 147.1, m 224-22S0(dec), [a];5 +31.4O (c 5, 5M HCI). Crystd from H20 acidified to pH 3.2 by adding 4 volumes of EtOH, and dried at 1 loo. Likely impurities are aspartic acid and cysteine.

229

Purification of Organic Chemicals

L-Glutamic acid-5-benzyl ester [1676-73-91 M 237.3, m 179-181O [a]?&, 19.3O (c 1, HOAc. Recrystd from H20 and stored at Oo. [Estrin Biochem Preps 13 25 19711. L-Glutamine [56-85-91 M 146.2, m 184-185O, [a];’ +31.8O (M HCI). Likely impurities are glutamic acid, ammonium pyroglutamate, tyrosine, asparagine, isoglutamine, arginine. Crystd from water. Glutaraldehyde [ I l l - 3 0 - 8 1 M 100.1, b 71°/10mm, as 50% aq soln. Likely impurities are oxidation products - acids, semialdehydes and polymers. It can be purified by repeated washing with activated charcoal (Norit XX) followed by vacuum filtration, using 15-20g charcoaVlOOm1 of glutaraldehyde soln. Vacuum distn at 60-65O/15mm, discarding the first 5-lo%, was followed by dilution with an equal volume of freshly distilled water at 70-75O, using magnetic stirring under nitrogen. The soln is stored at low temp (3-4O), i n a tightly stoppered container, and protected from light. Standardised by titration with hydroxylamine. [Anderson J Histochem Cytochem 15 652 1967. Glutaric acid [IIO-94-11 M 132.1, m 97.5-98O. Crystd from benzene, CHC13, distilled water or benzene containing 10%(w/w) of ethyl ether. Dried under vacuum. [70-18-81 M 307.3, m 195O(dec), [a]:

Glutathione EtOH.

dl-Glyceraldehyde

-21.3O (c 2, H20). Crystd from 50% aq

[56-82-61 M 90.1, m 145O. Crystd from EtOH/ethyl ether

Glycerol [56-81-51 M 92.1, m 18.2O, b 182°/20mm, 290°/760mm, d 1.261, n2’ 1.47352. Glycerol was dissolved in an equal volume of n-butanol (or n-propanol, amyl alcohol or liquid ammonia) in a water-tight container, cooled and seeded while slowly revolving in an ice-water slurry. The crystals were collected by centrifugation, then washed with cold acetone or isopropyl ether. [Hass and Patterson IEC 33 615 19411. Coloured impurities can be removed from substantially dry glycerol by extraction with 2,2,4trimethylpentane. Alternatively, glycerol can be decolorized and dried by treatment with activated charcoal and alumina, followed by filtering. Glycerol can be distd at 15mm in a stream of dry nitrogen, and stored in a desiccator over P2O5. Crude glycerol can be purified by digestion with conc H2SO4 and saponification with a lime paste, then re-acidified with H2SO4, filtered, treated with an anion exchange resin and fractionally distd under vacuum. Glycinamide hydrochloride Glycine see

[ I 668-10-61 M 110.5, m 186-189O (207-208O). Crystd from EtOH.

aminoacetic acid.

Glycine ethyl ester hydrochloride [623-33-61 M 136.9, m 145-146O, Glycine hydrochloride [6000-43-71 M 111.5, m 176-178O. Crystd from absolute EtOH. Glycine methyl ester hydrochloride

[5680-79-51

M 125.6, m 174O(dec). Crystd from MeOH.

Glycine p-nitrophenyl ester hydrobromide. [7413-60-71 M 277.1, m 214O (dec). Recryst from MeOH by adding ethyl ether. [Alners et al. Biochem Preps 13 22 19711. Glycocholic acid [475-31-01 M 465.6, m 154-15S0, [a];& +37O (c 1, EtOH). Crystd from hot water. Dried at looo. Glycol dimethyl ether see 1,2-Dimethoxyethane. Glycollic acid N-Glycylaniline

[79-14-11 M 76.1, m 81O. Crystd from ethyl ether [555-48-61 M 150.2. Crystd from water.

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