3442
NOTES
VOl. 74
haved exactly like the cholestatriene analog' upon shorter reaction time had the advantage that it was possible work in more concentrated solution. Thus, when 0.8 g. reduction with sodium borohydride. Thus a t low to of the tetraene I1 was refluxed for two hours with 1.6 g. of temperature, the yield of pure A5~7-22-isospirosta- sodium borohydride in 30 cc. each of dioxane and ethanol dien-3P-01 was ca. 70%, while a t 80" the product containing 3 cc. of water, precipitation with water afforded with m.p. 173was contaminated with an impurity absorbing a t 0.71 g. (97%) of crude A6,7'8(11)-trien-38-ol ~ ~mfi, logs 4.11. One recrys242 m,u, most likely the A4r6-dien-3-ol. As shown 1i8', [ ~ I N D+113", x E L 324 by both Gallagher4 and Daubenj the initial reaction tallization from methanol led to 0.5 g. (68%) of the pure appears to be hydrolysis of the enol acetate to the trienol. LABORATORIES unconjugated ketone, which undergoes rapid re- RESEARCH S. A. duction by the reagent to yield the unconjugated SYNTEX, LAGUNA MAYRAN 413 alcohol. Apparently, a t higher temperature some MEXICO CITY17,D. .'1 isomerization of the unconjugated ketone to the A4W-oneoccurs prior to reduction thus accounting for the formation of some of the Ads6-dien-3-01. In Fatty Acid Amides. V.' Preparation of N-(2this connection, it is of interest to note that the soAcetoxyethy1)-amides of Aliphatic Acids dium borohydride reduction of 3 - a ~ e t o x y - A ~ ~ ~ ' ~BY ~ ~EDWARD ( ' ' ) - T. ROE,THOMAS D. MILESAND DANIEL SWERN 22-isospiro~tatetraene~~ (11) afforded A5,7,9(11)-2%RECEIVED FEBRUARY 22, 1952 isospirostatrien-3~-olin essentially the same yield whether the reaction was carried out a t 10' or a t In a continuation of our studies on amides of SO". Evidently because of the longer conjugated fatty acids, we became interested in N-(2-acetoxytriene system, the isomerization of the initially ethyl)-amides. The only compound in this class formed unconjugated ketone to the conjugated previously described is N-(2-acetoxyethyl)-acetform is sufficiently slower so that reduction of the amide, prepared by treating ethanolamine with ketone predominates. acetic anhydride2 or with ketene.3 When we attempted to prepare it by a sli h t modification of Experimental" Sodium Borohydride Reduction of 3-Acetoxy-A3Jp7-22- the former method we obtained &acetamide. N-(2-Hydroxyethyl)-amideswere acetylated (97isospirostatriene (I).-An ice-cold mixture of 1.0 g. of 3a~etoxy-A3~~~~-22-isospirostatriene (1)lO in 40 cc. of dioxane 99%) by heating with a 100% excess of acetic anand 60 cc. of methanol was added in one portion to a solution hydride for six hours. During the initial stages of 1.6 g. of sodium borohydride in 40 cc. of methanol and 3 cc. of water. After standing a t 10' for 16 hours, the mix- the temperature rose exothermically to 85-95' ture was warmed for 30 minutes on the steam-bath, diluted after which it was readily controlled a t 75". Carewith water and the solid was collected; yield 0.94 g., X E ": ful control to prevent temperatures above 75' 270, 282 and 292 mp, log E 4.07, 4.09, 3.86. Two recrys- resulted in incomplete acetylation. Reactions tallizations from ethyl acetate furnished 0.55 g. 660%) of carried out a t 100' for three hours gave lower yields 4617-22-isospirostadien-38-01 with m.p. 187-190 , [a]2 n ~ and undesirable side products.
-177', 270,280 and 292 mp, log e 4.17, 4.19, 3.99, Experimental infrared spectrum ideiitical with that of an authentic speciAcetylmenlZ(reported: m.p. 188.5-190', [aI2O~-174'). Starting Materials .-The N-( 2-hydroxyethy 1)-amides ation of the crystalline mother liquors afforded an addi- were prepared from pure fatty acids by refluxing 1 mole of tional 10-13% of 45.7-22-isospirostadien-3p o l acetate with the acid with 1.5 moles of ethanolamine for two to six h o ~ r s . ~ m.p. 201-203', [a]20D -122", the identity of which was X-( 2-Hydroxyethyl)-acetamide, b .p. 145-146.7 (2.5 mm .) confirmed by comparison of its infrared spectrum with that and n2% 1.4709, was distilled through a 3-foot Vigreux of an authentic (reported: m.p. 202--205", [a]2 n ~ column. N-(2-Hydroxyethyl)-caproamidewas freed of ex-127'). cess ethanolamine by vacuum distillation and then crystalOn carrying out the reaction as above but refluxing for 2 lized from ethyl ether, 4 ml./g., a t 0' until pure. N-(% hours, the crude product (85% yield) exhibited m.p. 160Hydroxyethy1)-lauramide, m.p. 88.0-88.5', -palmitamide, 170", [ a l z 0-99", ~ 242, 270, 280 and 292 mp, log e m.p. 98', and -stearamide, m.p. 102', were crystallized directly from the crude reaction mixtures using 95% ethanol, 3.52,3.87, 3.89, 3.67. Sodium Borohydride Reduction of 3 - A ~ e t o x y - A ~ , ~ *4~ml./g., ~ ~ ( ~ ~a)t -O", 10 ml./g. a t O " , and 8 ml./g. a t 25', respectively. N-(2-Hydroxyethyl)-oleamide has already been 22-isospirostatetraene (II).-Obe gram of the tetraene 1 1 ' 0 upon treatment with sodium borohydride as described described .4 Preparation of N-(2-Acetoxyethy1)-amides.-These above (10") produced 0.635 g. (69'%) of A5,7,9(11)-22-isoamides were prepared by heating one mole of the N-(2spirostatrien3@-ol with m.p. 187-190°, [ a ]2 0 ~ 121', hydroxyethy1)-amide with two moles of acetic anhydride 324 mp, log E 4.14 and inflections a t 312 mp (log e for six hours in a nitrogen atmosphere. During the initial 4.10) and 338 mp (log e 4.00); lit.,13 n1.p. 187-190', [a]"D stages the ternpel ature rose exothermically to 85-95' after -1- 119", same ultraviolet absorption spectrum. The acewhich it was readily controlled at 7 5 " . tate showed m.p. 178-179", [ a ] " ~+173" (reported'3: After the acetylation of N-(2-hydroxyethyl)-acetamide, the reaction mixture was distilled a t 100 mm. to remove ex1n.p. 178-179", [ C Y ] ~ D+170°). The infrared spectra of both compounds were identical with those of authentic13 cess acetic anhydride and acetic acid formed. The pressure was then lowered to 5 mm. and the N-(2-acetoxyethyl)derivatives. In this instance, the reduction could be carried out a t 80" acetamide was distilled. The acetic anhydride and acetic without any diminution in yield, which in addition t o a acid were removed similarly from the N-(2-acetoxyethyl)caproamide reaction mixture, but in this case the crude ( 1 1 ) Melting points are uncorrected arid were determined in a sulamide remaining was crystallized five times from a mixture furic acid bath. Rotations and infrared spectra were measured in of equak portions of ether and petroleum naphtha, 3 ml./g. chloroform and ultraviolet absorption spectra in 95% ethanol solution. a t -20 .
XE";
+
We are grateful to Srta. Paquita Revaque and staff for these measurements. Thanks are due to Srtn. MarKarita Espinosa for technical assistance. (12j G. Rosenkranz, J. Komo arid J. Berlin, J. Or#. Chcm., 16, 290 ( 1% 1j .
(13) G. liosetikran~,1. H o m o , IC. 13atres and C Ujerassi, tbtd , 16, 2:lS ~.19j1).
11) For Paper IV, see J. A m . Oil Chemists' Soc., 49, 18 (1962). ( 2 ) 9.Frankel and M . Cornelius, Bcr., 81, 1654 (1918). (3) A. A. Ponomarev and Yu. B. Isaev. Zkur. Obshckci K h i m . , 40, 1079 (1950) [C. A , , 44, 9349d (1950)l. ( 4 ) 12, 't', K o e , J . T. Scanlan and 11. Swer,n, THIS. J O U R N A I , 71, 221; I!r,m).
July 5 , 1952
NOTES
3443
TABLE I r\'-(2-ACETOXYETHYL)-AMIDES OF ALIPHATIC ACIDS N-(2-
Acetoxyethyl).
Reaction product Yield, M.P.. % =C.
Y.P.,
Yield,
%
C.
Crystallized product Carbon, % Hydrogen, % Calcd. Found Calcd. Found
Saponification Nitrogen, % N0.O Calcd. Found Calcd. Found
Acetamideh .. ..... 71" ..... 49.6 49.8 7.64 7.35 9.65 9.33 386.5 393.8 Caproamide 99
