Ampoule

Liquid can be dispensed into plastic or metal trays for bulk freeze-drying. For single-dose applications, freeze-drying in ampoules or vials is more appropriate. 

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Figure Bl.27.5. A typical solution calorimeter with thennometer, heater and an ampoule on the base of the stirrer which is broken by depressing it against the ampoule breaker. (Reproduced with pennission from Suimer S and Wadso I 1959 Acta. Chem. Scand. 13 97.)...

Butyryi chloride (butanoyl chloride) [141-75-3] M 106.6, f -89°, b 101-102°/atm, 1.026, Hp 1.412. Check IR to see if there is a significant peak at 3000-3500 cm (br) for OH. If OH is present then reflux with less than one mol equiv of SOCI2 for Ih and distil directly. The fraction boiling between 85-100° is then refractionated at atm pressure. Keep all apparatus free from moisture and store the product in sealed glass ampoules under N2. LACHRYMATORY - handle in a good fume hood. [Org Synth Coll Vol I 147 794/.]... 

Crotonaldehyde (2-butenal) [123-73-9] M 70.1, b 104-105 , d 0.851, n 1.437. Fractionally distd under N2, through a short Vigreux column. Stored in sealed ampoules. Stabilised with 0.01% of 2,6-di-tert-butyl-p-cresol... 

Fractionally distd, then 35mL was sealed with about 7g KOH pellets in a borosilicate glass ampoule and heated at 135° for 48h. The ampoule was cooled and opened, and the liquid was resealed with fresh KOH in another ampoule and heated as before. This process was continued until no further decomposition was observed. The substance was then washed with distilled water, dried (CaS04) and distd. [Grafslein Anal Chem 26 523 1954.]... 

Pivaloyl chloride (trimethylacetyl chloride) [3282-30-2] M 120.6, b 57.6"/150mm, 70.5-71/250mm, 104"/754mm, 104-105"/atm, 105-108"/atm, d 1.003, n p 1.4142. First check the IR to see if OH hands are present. If absent, or present in small amounts, then redistil under moderate vac. If present in large amounts then treat with oxalyl chloride or thionyl chloride and reflux for 2-3h, evap and distil residue. Strongly LACHRYMATORY - work in a fumecupboard. Store in sealed ampoules under N2. [Traynham and Battiste J Org Chem 22 1551 1957, Grignard reactns Whitmore et al. J Am Chem Soc 63 647 1941.]... 

Thioglycollic acid [68-11-1] M 92.1, b 95-96 /8mm, d 1.326, n 1.505, pK 3.42, pK j 10.20. Mixed with an equal volume of benzene, the benzene is then distd to dehydrate the acid. After heating to 100° to remove most of the benzene, the residue was distd under vacuum and stored in sealed ampoules at 3°. [Eshelman et al. Anal Chem 22 844 I960.]... 

Thiothienoyltrifluoroacetone [4552-64-1] M 228.2, m 61-62". Easily oxidised and has to be purified before use. This may be by recrystd from benzene or by dissolution in pet ether, extraction into IM NaOH soln, acidification of the aqueous phase with 1-6M HCl soln, back extraction into pet ether and final evapn of the solvent. The purity can be checked by TLC. It was stored in ampoules under nitrogen at 0" in the dark. [Muller and Rother Anal Chim Acta 66 49 1973.]... 

VinyInaphthaIene [826-74-4] M 154.2, b 124-12S /lSnim. Fractionally distd under reduced pressure on a spinning-band column, dried with CaH2 and again distd under vacuum. Stored in sealed ampoules in a freezer. 

Aluminium bromide [7727-15-3] M 266.7, m 97°, b 114°/10mm. Refluxed and then distilled from pure aluminium chips in a stream of nitrogen into a flask containing more of the chips. It was then distd under vacuum into ampoules [Tipper and Walker 7 Chem Soc 1352 1959], Anhydrous conditions are essential, and the white to very light brown solid distillate can be broken into lumps in a dry-box (under nitrogen). Fumes in moist air. 

Antimony trichloride [10025-91-9] M 228.1, m 73", b 283", pK 1.4, pK j ll.O (11.8), PKI 12.95 (for Sb " " aquo). Dried over P2O5 or by mixing with toluene or xylene and distilling (water is carried off with the organic solvent), then distd twice under dry nitrogen at 50mm, degassed and sublimed twice in a vacuum into ampoules. Can be crystd from CS2. Deliquescent. Fumes in moist air. 

Phosphorus pentoxide [1314-56-3] M 141.9, m 562 , b 605 . Sublimed at 250° under vacuum into glass ampoules. Fumes in moist air and reacts violently with water. HARMFUL VAPOURS and attacks skin. 

Silver difluoride [7783-95-1J M 145.9, m 690 , d 4.7. Highly TOXIC because it liberates HF and F2. Very hygroscopic and reacts violently with H2O. It is a powerful oxidising agent and liberates O3 from dilute acids, and I2 from I soln. Store in quartz or iron ampoules. White when pure, otherwise it is brown-tinged. Thermally stable up to 700°. [Handbook of Preparative Inorganic Chemistry (Ed. Brauer) Vol I 241 1963.]... 

N-(Thexyl dimethylsilyl)dimethylamine (N-[2,3-dimethyl-2-butyl]dimethylsilyl dimethyl-amine) [81484-86-8] M 187.4, b 156-160°/720mm. Dissolve in hexane, filter, evaporate and distil. Colourless oil extremely sensitive to humidity. It is best to store small quatities in sealed ampoules after distillation. For estimation of purity crush an ampoule in excess O.IN HCl and titrate the excess acid with O.IM NaOH using methyl red as indicator. [Helv Chim Acta 67 2128 1984.]... 

Dissolve in Et20, add quinol (500mg for 300mL), dry over Na2S04, filter, evaporate and distil under dry N2. It is a clear liquid if dry and decompose very slowly. In the presence of H2O traces of tributyl tin hydroxide are formed in a few days. Store in sealed glass ampoules in small aliquots. It is estimated by reaction with aq NaOH when H2 is liberated. CARE stored samples may be under pressure due to liberated H2. [J Appl Chem 7 366 1957.]... 

Trimethylsilyloxy-3-penten-2-one cis) (acetylacetone enol trimethylsilyl ether) [13257-81-3 M 172.3, b 66-68"/4mm, 61-63"/5mm, d4 0.917, Up 1.452. Fractionally distilled and stored in glass ampoules which are sealed under N2. It hydrolyses readily in contact with moisture giving, as likely impurities, hexamethyldisiloxane and 2,4-pentanedione. [J Am Chem Soc 80 3246 795S.]... 

Vanadyl trichloride (VOCI3) [7727-18-6] M 173.3, m-79.5°, b 124.5-125.5°/744mm, 127.16°/760mm, d 1.854, d 1.811. Should be lemon yellow in colour. If red it may contain VCI4 and CI2. Fractionally distil and then redistil over metallic Na but be careful to leave some residue because the residue can become EXPLOSIVE in the presence of the metal USE A SAFETY SHIELD and avoid contact with moisture. It readily hydrolyses to vanadic acid and HCl. Store in a tightly closed container or in sealed ampoules under N2. [Inorg Synth 1 106 1939, 4 80 1953.]... 

R-(+)-Pantothenic acid sodium salt (7V-[2,4-dihydroxy-3,3-dimethylbutyryl] P-alanine Na salt) [867-81-2] M 241.2, [aJ +27.1 (c 2, H2O), pK 4.4 (for free acid). Crystd from EtOH, very hygroscopic (kept in sealed ampoules). The free acid is a viscous hygroscopic oil with [a] +37.5 (c 5, H2O), easily destroyed by acids and bases. 

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