Improved Tensimeter-Still

Abstract

STUDIES of high-boiling derivatives of lactic acid, need arose for a device which would serve as a simple low-pressure still and also make possible accurate vapor pressure-i.e., boiling point-measurements in the low-pressure region-viz., 0.02 to 10 mm. of mercury.

MIXED ESTERS OF LACTIC AND CARBONIC ACIDS. n-ALKYL CARBONATES OF METHYL AND BUTYL LACTATES, AND BUTYL CARBONATES OF n-ALKYL LACTATES

“…The two sets of constants gave the same calculated values for the compounds of highest molecular weight, but differed by 0.4 for the compounds of lowest molecular weight, Eisenlohr's being the higher. 6 This compound has been reported by Ritchie, J. Chem. Soc., 1054 (1935).…”

“…Physical constants. Boiling points used in the construction of Figures 1 and 2 were determined by use of an improved tensimeter-still (6).…”

PREPARATION AND PROPERTIES OF N-n-ALKYLLACTAMIDES2

“…The boiling points (Fig. 1) of the first eight lactamides (Table I), with the exception of butyl, were determined in a tensimeter-still (15); an automanometer still ( 14) was used for the butyl derivative. For lactamide and for the dodecyl and higher lactamides (Fig.…”

“…Physical constants. The boiling points at low pressures (Figures 1 and 2) were carefully determined in equipment known to give accurate results (14,15). Lactamide and N-n-butyllactamide had almost identical boiling points in the 1) N-n-DODECYL 3)N-n-HEXADECYL 2) N-n-TETRADECYL 4) N-n-OCTADECYL range studied.…”

The Reaction of Selenium Dioxide with Levulinates

“…(3) hydroxyl analysis, (4) conversion of (II) to (I) by an equivalent of water, (5) analysis of the picrate of (II), ( 6) molecular refraction (the observed molecular refraction, 47.75, agreed more closely with that calculated3 for (Ila), 47.76, than with that for an N-alkene lactamide, 48.72), and (7) analogy with the work of Smith and Adkins,4 who attempted to distil N-(l,l-dimethyl-3-hydroxybutyl)-acetamide at 130-140°, and obtained instead 2,4,4,6-tetramethyl-5,6-dihydrol,3,4H-oxazine. The two methyl groups on the carbon adjacent to the amide nitrogen promote the dehydration of…”