Parts by volume

The real atmosphere is more than a dry mixture of permanent gases. It has other constituents—vapor of both water and organic liquids, and particulate matter held in suspension. Above their temperature of condensation, vapor molecules act just like permanent gas molecules in the air. The predominant vapor in the air is water vapor. Below its condensation temperature, if the air is saturated, water changes from vapor to liquid. We are all familiar with this phenomenon because it appears as fog or mist in the air and as condensed liquid water on windows and other cold surfaces exposed to air. The quantity of water vapor in the air varies greatly from almost complete dryness to supersaturation, i.e., between 0% and 4% by weight. If Table 2-1 is compiled on a wet air basis at a time when the water vapor concentration is 31,200 parts by volume per million parts by volume of wet air (Table 2-2), the concentration of condensable organic vapors is seen to be so low compared to that of water vapor that for all practical purposes the difference between wet air and dry air is its water vapor content. 

All details in the reagent monographs concerning mobile phases are given in parts by volume unless it is specifically stated otherwise... 

Boron trifluoride diglymate is prepared (2) by mixing one part (by volume) of distilled boron trifluoride etherate with two parts (by volume) of diglyme. The ether is pumped otf under vacuum... 

V0I.T., abbrev. (VolumenteU) part by volume, voltaisch, a. voltaic. 

To a solution of 180 parts of -benzyl N-benzyloxycarbonyl-L-aspartvI-L-phenylalanine methyl ester in 3,000 parts by volume of 75% acetic acid is added 18 parts of palladium black metal catalyst, and the resulting mixture is shaken with hydrogen at atmospheric pressure and room temperature for about 12 hours. The catalyst is removed by filtration, and the solvent is distilled under reduced pressure to afford a solid residue, which is purified by re-crystallization from aqueous ethanol to yield L-aspartyl-L-phenylalanine methyl ester. It displays a double melting point at about 190°C and 245°-247°C. 

After the addition of 75 parts by volume of methanol and 150 parts by volume of acetic acid of 15% strength with adequate mixing, the solution is extracted with 2 portions each of 100 parts by volume of hexane. The combined hexane extracts are extracted with 15 parts by volume of acetic acid of 15% strength. The latter extract is added to the above acetic acid phase which is then extracted with 3 portions each of 75 parts by volume and 1 portion of 50 parts by volume of ethylene chloride. 

The first three extracts are combined and washed with 60 parts by volume of 2 N sodium carbonate solution and then with 60 parts by volume of distilled water. These washing solutions are saved and used for the yvashing of the 4th and final ethylene chloride extract. The combined ethylene chloride extracts are dried over sodium sulfate, filtered and evaporated in vacuo to a constant weight of a tan, frothy solid. One part by weight of this residue is dissolved in 1.5 parts by volume of warm methanol and the solution cooled to 5°C for 18 hours, whereby crystallization of a mixture containing principally reserpine sets in. After filtering this mixture and yvashing it with cool methanol, the filtrate is freed of Solvent in vacuo. 

The soon crystallizing dihydrochloride is separated by filtration, dried and recrystallized from 120 parts by volume of ethanol. Thus, after drying for 3 days over 8265, 40-50 grams (66-70% of the theoretical) of N,N -bis-[(3,4,5-trimethoxy benzoloxy)propyl] homopiperazine dihydrochloride containing 1 mol of water of crystallization is obtained. This product has a melting point at 194°-19B°C. 

To a solution of 13 parts of compound A and 12 parts by volume of absolute pyridine in 80 parts by volume of absolute dioxane there are added dropwise and under constant stirring 35 parts of 3,4.5-trimethoxybenzoyl chloride dissolved in 70 parts by volume of absolute dioxane in the course of 30 minutes. The mixture is stirred for a further 3 hours at a temperature of 100°C and the excess solvent is then evaporated in vacuo. The residue of the evaporation is treated with ethyl acetate and saturated sodium carbonate solution, whereafter the organic phase is separated, treated with water, dried with sodium sulfate and the solvent is removed in vacuo. The residue thus obtained is taken up In ether and separated from 4 parts of insoluble trimethoxybenzoic acid anhydride by filtration. After evaporation of the ether there are obtained 32.5 parts of N,N -dimethyl-N,N -bis-[3-(3,4,5-trlmethoxybenzoxy)-propyl] -athylene diamine, corresponding to a yield of 86% of the theoretical. MP 75°C to 77°C. 

A suspension of 4 parts NaNH in 50 parts by volume of absolute benzene are then added dropwise at 50° to 60°C after which the mixture is boiled for an hour under reflux. 13 parts of 3-dimethylamino n-propyl chloride are then added dropwise at 40° to 50°C and the mixture is boiled for 10 hours under reflux. After cooling, the benzene solution is thoroughly washed with water, whereupon the basic constituents are extracted with dilute hydrochloric acid. 

A suspension of 6 parts by weight of 5-acetylimino-4-methyl-2-benzylmercapto-A -1,3,4-thiadiazoline in 180 parts by volume of 33% aqueous acetic acid was chlorinated at 5°C for 30 minutes. The solid was filtered off, dried, and added portion-wise to 100 parts by volume of liquid ammonia. The ammonia was removed under a stream of dry nitrogen. 

The residual solid was partially dissolved in 10 parts by volume of water, filtered, and acidified to give 5-acetylimino-4-methyl-A -1,3,4-thiadiazoline-2-sulfonamide. The product was purified by two recrystallizations from hot water. 

The carbonyl chloride reactant was prepared by reacting 2-imidazolidone with methane sulfonyl chloride then that product with phosgene. The mixture was stirred for 10 minutes at 0°C and subsequently further stirred at room temperature until no further addition of triethylamine was necessary to maintain a pH value of 7 to B. 150 parts by volume of water were added and the tetrahydrofuran was largely removed in a rotary evaporator at room temperature. 

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