THE REACTION OF THE POTASSIUM SALT OF

WITH ACETYL CHLORIDE AND ACETONE

B. G. Sankov, V. I. Erashko, S. A~ S h e v e l e v , a n d A. A. F a i n z i l ' b e r g

T R I N I T R O M E T H A N E

UDC 542.91 + 547.414.2 + 547.297

Prev ious ly we showed that sa l t s of t r i n i t rome thane r e a c t with aeyl hal ides in var ious solvents (aeetoui t r i le and the dimethyl e ther of ethyleneglycol) giving the cor responding O-acy l der iva t ives of t r i - n i t romethane [1]. Continuing the invest igat ion of the acylat ion of the t r in i t romethane anion in the presen t work we have invest igated the r eac t ion of the po tass ium sal t of t r in i t romethane with aeety l chloride in abs acetone in which the po tass ium sal t d i s so lves well. It was shown that in this soIvent the t r a n s f o r m a - t ion of the r eagen t s occurs r a t h e r rapid ly , however acylat ion of the t r in i t romethane anion does not take place but comple te ly different p r o c e s s e s occur .

The r eac t ion was ca r r i ed out at ~ 20~ for a day. Under these conditions the potass ium sal t of t r i - n i t romethane r eac t ed comple te ly and a quanti tat ive yield of po tass ium chloride separa ted out f rom the r eac t ion mix tu re . 1 ,1 ,1 -Tr in i t ro -2 ,2 -d ime thy lpen t an -4 -one (I) was shown to be the main reac t ion product (yield 70%), this was identified by e l e m e n t a r y ana lys i s , IR spec t rum, the p repa ra t ion of its 2 ,4 -d in i t ro - phenylhydrazone, and a lso compar i son with an authentic sample . F rom the reac t ion mix ture were a lso isolated t r in i t romethane and the ace ta te of diacetone alcohol (II) s l ightly contaminated with diacetone alcohol (III). F u r t h e r m o r e the p r e s ence of ace t ic acid and mes i ty l oxide (IV) among the reac t ion products was es tab l i shed chromatograph ica l ly .

Natura l ly it was a s sumed that ketone (I) is fo rmed as a r e su l t of the addition of t r in i t romethane to mes i ty l oxide,* while both of these compounds a r i s e in the r eac t ion mix tu re as a r e s u l t of t r ans fo rma t ions of the or ig ina l subs tances . Actually, as a s e p a r a t e expe r imen t conf i rmed, mes i ty l oxide is rap id ly formed f r o m acetone under mild conditions (~ 20 ~ by the act ion of ace ty l chloride. The water which s e p a r a t e s during the condensation of the acetone hydro lyzes the acetyl chloride to acet ic acid and hydrogen chloride which l ibera tes f r ee t r in i t romethane f r o m the po ta s s ium salt; the lat ter adds to mes i ty I oxide (IV) giving the ketone (I). As r e g a r d s the fo rmat ion of diacetone alcohol (III) it is evidently obtained as a r e su l t of the aldol condensation of acetone under the influence of t r a c e s of alkal i which may be contained in the po tas - s ium sal t of t r in i t romethane , p r epa red by the act ion of KOH on te t ran i t romethane~ [2]. The fo rmat ion of the aceta te of diacetone alcohol (II) can be explained by the subsequent aeylat ion of diacetone alcohol by acetyl chloride in the course of the r eac t ion .

All of the t r an s fo rm a t i ons occur r ing in acetone can be r e p r e s e n t e d by the following scheme

[-~ (CHs)~C=CHCOCHa --~ CHaCOOH ~ HC1 (IV) ~ [(N02)~C]- K+

CH~COC1

CH~COCH8

HC(NO~.)s I

(O~.N)aCC(CHs)eCH2COCHs (i)

CH~COC1 1-_. CHaCOCtI~.C(CHa)~.OH - ~ CHaCOCH2C(CHa)20COCHa

(III) (II)

* As was shown by us t r in i t romethane r ead i ly adds to mes i ty l oxide in the absence of ca ta lys ts . On dissolving the po tass ium sa l t of t r in i t romethane in acetone (~ 20 ~ (III) is fo rmed at once (in ~ 8% yield

calculated on the acetone) whereas in the p r e s e n c e of spec ia l ly purif ied po tass ium sal t of t r in i t romethane

the fo rmat ion of (III) is not observed .

N. D. Zel inski i Inst i tute of Organic Chemis t ry , Academy of Sciences of the USSR. Trans la t ed f rom Izves t i ya Akademii Nauk SSSR, Ser iya Khimieheskaya , No. 12, pp. 2769-2771, December , 1967. Original a r t i c l e submit ted May 24, 1967.

2640

EXPERIMENTAL

The Reaction of the Potassium Salt of Trinitromethane with Acetyl Chlo- r i d e i n A c e t o n e . To a solution of 18.9 g of the potassium salt of t r ini t romethane [2] in t60 ml of abs acetone at 20-22 ~ 7.8 ml (8.64 g) of acetyl chloride was added dropwise with s t i r r ing and the mixture was left to stand at r o o m tempera tu re for 24 h. The precipitate of potassium chloride which separated was f i l tered off (weight 7.3 g or 98% of theory). The acetone was distilled off at reduced p re s su re and the res idue distil led in vacuum collecting the fract ions: I) bp 38-50 ~ (2.5 ram), 2.15 g and II) bp 100-102 ~

(1.5 mm), 17.55 g.

Fu r the rmore , in the t rap cooled to --70 ~ a smal l quantity of low boiling liquid was collected in which mesi ty l oxide and acetic acid were identified by G LC.

Frac t ion I, according to the UV spec t roscopic data, contained 44.7% of t r in i t romethane (determined by the molar absorpt ion coefficient of the t r in i t romethane anion in water at k = 350 m#), i.e., 0.96 g (or 6.3% calculated on the potassium salt taken).

On dissolving fract ion I in abs ether and passing in gaseous NH 3 (at 0 ~ 1.05 g of the ammonium salt of t r in i t romethane was obtained (identified by convers ion into the potassium salt); this also corresponded to a content of ~ 44% of t r iu i t romethane in this fraction. After separat ion of the ammonium salt the ether f i l t rate was evaporated and the residue distilled. 1.1 g of a substance was obtained with bp 38-40 ~ (3. mm); nD20 1.4223. According to GLC data it was a mixture of diacetone alcohol and its acetate* (in the ra t io of N I : 20).

Fract ion II was 1 ,1 ,1- t r in i t ro-2 ,2-d imethylpentan-4-one (yield 70% calculated on the potassium salt of t r ini t romethane); mp 22-23 ~ (from 70% ethanol). Found %: C 34.32, 34.35; H 5.03, 5.00; N 16.67, 16.73. C?HllOTN 3. Calculated %: C 33.73; H 4.42; N 16.87. IR spectrum: 802, 1302, 1585 and 1600 cm - 1 - t r i - n i t romethyl group; 1730 cm -1 -- C = O .

A mixture with an authentic sample obtained f rom tr ini t romethane and mesi ty l oxide melted without depress ion.

2 , 4 - D i n i t r o p h e n y l h y d r a z o n e (yield 84%) was orange c rys ta l s with mp 130 ~ (from ethanol-- ethyl acetate, 2: 1). Found %: C 36.49, 36.58; H 3.68, 3.52; N 22.61, 22.58. C13H15Ot0N 7. Calculated %: C 36.37; H 3.52; N 22.84.

C O N C L U S I O N S

On reac t ing the potassium salt of t r in i t romethane with acetyl chloride in abs acetone acylation of the t r in i t romethane anion does not occur and the main product of the reac t ion is 1 ,1 ,1 - t r in i t ro -2 ,2-d imethy l - pentan-4-one formed as a resu l t of the addition of t r ini t romethane to mesi ty l oxide which a r i ses f rom ace - tone in the p rocess of react ion.

1.

2. 3.

LITERATURE CITED

S. A. Shevelev, V. I. Erashko, B. G. Sankovi, and A. A. FainzilTberg, Izv. AN SSSR, Ser. I~irn., 1967, 1630. F. Borgardt, A. Seeler, and P. Noble, J. Organ. Chem., 31, 2806 (1966). H. Gault and C. Lumbroso, Compt. rend., 24_~3, 1330 (1956).

* The acetate ofdiacetone a lcohol requi red as standard for compar i sonwas obtained according to [3].

264i