0 0 0 0 0 a b c d e 2 3 Fig. 2. Thin-layer chromatogram of (a) chloranil, (b) tetrachlorohydroquinone, (c) l,Z-naphthoquinone, (d) 1,4-naphthoqumone, ( e ) mixture. Adsorbant and eluant as for Fig. 1. Color of thecomplexes: yellow-red.
Cellulose ester of' ( I ) :
Mercerized cellulose[41 (10.6 g) is made into a slurry with pyridine (22 ml) and djoxane (78 ml). The acid chloride (56 g) of ( I ) in dioxane (200 ml) is added and the whole is heated at 95 "C for 24 h, and the ester is then precipitated by pouring the mixture into methanol (500 ml). The ester is isolated, boiled with acetone, triturated with a little methanol for 3 h in a ball mill, filtered off, and dried (yield 39.6 g; insoluble in alcohols, sparingly soluble in chlorinated hydrocarbons; sap.
Val: found 75.0% of acyl; calc. for diester 71.7% and for triester 79.3 %).
C$litlose ester of (2) :
Cellulose (11.3 g) in pyridine (23 ml) and dioxane (150 ml) is heated with the acid chloride (68 g) of (2) in dioxane (220 ml) as above for 48 h. The viscous solution is poured into methanol(1 I)+ acetone(500ml). Theprecipitatedester is filtered off, ground twice with methanol/acetone, and triturated with a little acetone in a ball mill for 2 h. It is insoluble in most organic solvents (yield 50 g; sap. Val: found 75.3 % of acyl; calc. 74.4% for diester).
For thin-layer chromatography 5 g of the cellulose ester of ( I ) is homogenized on a shaker with 0.3 g of gypsum, 8 ml of methanol, and 5 ml of water. For the ester of (21, 4 g are similarly treated with 0.2g of gypsum, 20ml of methanol, and 5 ml of water. These materials are placed on plates, dried in the air, and heated at 90-100 O C shortly before use.