1.3- Indandiones

A-4-Thiazoline-2-ones and ring substituted derivatives are usually prepared by the general ring-closure methods described in Chapter II. Some special methods where the thiazole ring is already formed have been used, however. An original synthesis of 4- 2-carboxyphenyl)-A-4-thiazoline-2-one (18) starting from 2-thiocyanato-2-halophenyl-l-3-indandione (19) has been proposed (Scheme 8) (20, 21). Reaction of bicyclic quaternary salts (20) may provide 3-substituted A-4-thiazoline-2-one derivatives (21) (Scheme 9) (22). Sykes et al. (23) report the formation of A-4-thiazoline-2-ones (24) by treatment ef 2-bromo (22) or 2-dimethylaminothiazole (23) quaternary salts with base (Scheme 10). 

Quinoline Dyes. The reaction of 2-methylquinoline with phthahc anhydride produces a 2 1 mixture of 2-(2-quinolinyl)-l,3-indandione... 

Pivalyl-l, 3-indandione, see Pindone Plaster of Paris, see Calcium sulphate Platinum Metal 1... 

Anticoagulant therapy was developed with the adventitious discovery of dicoumarol (8). A fuller discussion of the rationale for the use of such compounds is found in the chapter on Five-Mem-bered Heterocycles Fused to One Benzene Ring. The reader s attention is directed, however, at the fact that dicoumarol is a polycarbonyl compound containing a very acidic hydrogen. A series of similarly acidic 1,3-indandiones have been found to constitute an additional class of anticoagulant agents. 

Condensation of an appropriately substituted phenylacetic acid with phthalic anhydride in the presence of sodium acetate leads to aldol-like reaction of the methylene group on the acid with the carbonyl on the anhydride. Dehydration followed by decarboxylation of the intermediate affords the methylenephthal-ides (12). Treatment of the phthalides with base affords directly the indandiones, probably via an intermediate formally derived from the keto-acid anion (13). The first agent of this class to be introduced was phenindandione (14) this was followed by anisindandione (1S) and chlorindandione (16). ... 

To a hot solution of 20.6 g of sodium in 400 ml of absolute ethanol, there is added a solution of 110 g of phthalide and 110 g of p-methoxybenzaldehyde. A vigorous reaction ensues and one-helf of the alcohol is distilled off over a two hour period. Ice and water are added to the red solution end the diluted solution is ecidified with hydrochloric acid. The resulting gum solidifies end the aqueous phase is removed by decantation. The crude solid is recrystallized twice from two liters of ethenol yielding 2-(p-methoxyphenyl)-1,3-indandione as pale yellow crystals, MP155°-156°C. 

Common Name 2-diphenvlacetvM,3-diketohydrindene 2-diphenylacetyl-1,3-indandione Structural Formula o... 

The light yellow solid which separated was collected by filtration the filtrate was reserved for treatment as described below. Suspension in water of the solid, which weighed 12 grams, and acidification of the mixture with dilute hydrochloric acid produced a gum which soon crystallized. Recrystallizatiori of this solid from ethanol gave 10.2 grams (30%) of 2-di-phenylacetyl-1,3-indandione as a light yellow crystalline solid, which melted at 146 -147°C. 

The filtrate mentioned above consisted of 3 layers. An oily layer which was present between the aqueous and benzene layers was separated, acidified and extracted with ether. The aqueous layer was likewise separated, acidified and extracted with ether. The extracts were combined, dried and evaporated to yield a heavy gum which was crystallized from ethanol to give an additional 2.5 grams of product which melted at 146°-147 C. The total yield of 2-diphenylacetyl-1,3-indandione was 12.7 grams (37%). 

Quinoline yellow (E 104, Cl Food Yellow 13) is a quinophthalone dye consisting of a mixture of disulfonates (minimum 80%), monosulfonates (maximum 15%), and trisulfonates (maximum 7%) as sodium salts, obtained by the sulfonation of 2-(2-quinolyl)-l,3-indandione. The calcium and potassium salts are also permitted. Quinoline yellow is a yellow powder or granules, soluble in water, sparingly soluble in ethanol. The absorption maximum is at 411 nm in aqueous acetic acid solution, pH 5, = 865. It is not permitted as food colorant in the US. "... 

Phenyl indandiones With an acidic hydrogen often interfere with clot formation. When electron withdrawing groups are present in the p-position, acidity is increased and activity goes up. The opposite effect is seen with electron-donating substituents. Synthesized in the usual way, the anticoagulant bromindione (15) results from sodium acetate-catalyzed condensation of phthalic anhydride and p-a-bromophenyl-acetic acid. ... 

Detection powders and fingerprint development kits commonly contain cream- or yellow-colored ninhydrin crystals or a solution of dissolved ninhydrin. Ninhydrin (also known as 1,2,3-indantrione, monohydrate 2,2-dihydroxy-1,3-indandione triketohydrindene, monohydrate and triketohydrinden hydrate) has the structure presented in Fig. 13.3.1. Ninhydrin will react with a free a-amino group, -NH2. This group is contained in all amino acids, and analysis with ninhydrin is often performed to verify the presence of amino acids. When a-amino acids (i.e., amino acids with the structure NH2-CHR-COOH) react with ninhydrin, a characteris-... 

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