M. Longobardi

Application of TLC and HPTLC in the analysis of semipermanent hair dyes

Semipermanent or direct colouring includes any product capable of affecting to some extent a change in the natural hair colour that will last through at least five shampoo washings. Semipermanent dyes are simple and easy to use, as opposed to oxidation dyes, and are normally formulated for application on nonbleached hair. Following increases in supply of such formulations, we have started an analysis for quality control purposes of 21 commonly marketed dyestuffs (nitroaminobenzenes, anthraquinone and Arianor dyes) and 20 colouring products manufactured by four leading companies. By using TLC (silica gel and reversed phase) and HPTLC (silica gel) procedures we have determined relative retention values to 1,3‐diamino‐4‐nitrobenzene of standards and dyes found in the commercial products. All the values reported (standards and samples) are the average of five analytical results (+/‐SD).

Synthesis of quaternary ammonium bromides of 5‐[4‐(ω‐dialkylaminoalkoxy)phenyl‐methylene]‐1, 3, 3‐trimethyl‐2‐oxabicyclo [2.2.2]octan‐6‐ones as potential UV sunscreens

Materials and methods for the synthesis of eight quaternary ammonium bromides of 5‐[4‐(ω‐dialkylaminoalkoxy)phenylmethylene]‐1,3,‐trimethyl‐2‐oxabicyclo[2.2.2]octan‐6‐ones are illustrated. They were routinely prepared starting from cineole aminoethers by reaction with primary alkyl bromides and their physico‐chemical data are reported. These substances have been tested for UV filtering and/or microbiological activity. The substances have their UV absorption maxima at 315–322 nm. Tests on antimicrobial activity were performed using benzalkonium chloride as reference standard. All quaternary ammonium bromides were totally inactive against Escherichia coli (Gram —) and partially active on Staphylococcus aureus (Gram +). These preliminary findings seem to indicate that these new quaternary ammonium bromides could be considered as potential UV sunscreens.

Odour properties of some 5-alkoxy and 5-aryloxymethylene-1,3,3-trimethyl-2-oxabicyclo[2.2.2]octan-6-ones.

The synthesis of 5‐alkoxy and 5‐aryloxymethylene‐1,3,3‐trimethyl‐2‐oxabicyclo[2.2.2]octan‐6‐ones by reaction of (+)‐5‐hydroxymethylene‐1,3,3‐trimethyl‐2‐oxabicyclo[2.2.2]octan‐6‐one with a number of saturated or unsaturated alcohols and phenols in order to check how substituents affected the fragrance, is described. Materials and methods for the synthesis of fifteen terpenyl ethers are illustrated. The terpenyl ethers have been tested for their olfactive character and the preliminary findings seem to indicate that some aliphatic ethers showed interesting notes such as floral aroma, honey like aroma, green floral note.

5-[4-(omega-dialkylaminoalkoxy)phenylmethylene] -1,3,3-trimethyl-2-oxabicyclo[2.2.2]octan-6-ones with platelet antiaggregating and other activities.

The synthesis of 5-[4-(omega-dialkylaminoalkoxy)phenylmethylene]- 1,3,3-trimethyl-2-oxabicyclo[2.2.2]octan-6-ones 3 by reaction of some 4-(omega-dialkylaminoalkoxy)benzaldehydes with (+)-1,3,3-trimethyl-2-oxabicyclo [2.2.2]octan-6-one in the presence of sodium methoxide is described. Some aminoethers 3 showed platelet antiaggregating activity in vitro superior or comparable to that of acetylsalicylic acid, as well as weak antiarrhythmic activity in rats and moderate infiltration anesthesia in mice.

Reduction of 5-hydroxymethylene-cis-caran-4-one with complex hydrides

Reduction of 5-hydroxymethylene-cis-caran-4-one (I) with lithium aluminium hydride gave 5-methylene-cis-caran-cis-and -trans-4-ols [(III) and (IV)] as main products, and small quantities of cis-5-methyl-cis-caran-4-one (II) and 5-hydroxymethyl-cis-car-4-ene (V), whereas reduction with sodium borohydride gave mainly 5-hydroxymethylcaran-4-ol (VI) with a lesser quantity of compounds (II)–(V). The mechanisms of these reactions are discussed.

Reaction of Ketenes with N,N‐Disubstituted α‐Aminomethylene Ketones. Part 24. 2H‐Pyrano‐(3,2‐d)‐1‐benzoxepin Derivatives with Platelet Antiaggregating and Other Activities.

The synthesis of some N,N-disubstituted 4-amino-5,6-dihydro-3-phenyl-2H-pyrano[3,2-d]-1-benzoxepin-2 -ones by reaction of phenylchloroketene with a series of N,N-disubstituted (E)-4-aminomethylene-3,4-dihydro-1-benzoxepin-5(2H)-ones, followed by dehydrochlorination of the primary adducts with DBN, is described. Some of these compounds showed a platelet antiaggregating activity in vitro slightly superior to that of acetylsalicylic acid, as well as weak local anesthetic and antiinflammatory activities in mice and rats, respectively.

Synthesis of new N, N-disubstituted 4-amino-5,6-dihydro-3-phenyl-2H-thieno[2,3-H]-1-benzopyran-2-ones

The synthesis of some N,N-disubstituted 4-amino-5,6-dihydro-3-phenyl-2H-thieno[2,3-h]-1-benzopyran-2-ones (4a-f), by reaction of phenylchloroketene with a series of N,N-disubstituted (E)-5-aminomethylene-6,7-dihydrobenzo[b]thiophen-4(5)-ones, followed by dehydrochlorination in situ of the primary adducts with DBN, is described. A moderate local anaesthetic activity was observed in the title compounds, particularly in 4e.

Reaction of Ketenes with N,N-Disubstituted α-Aminomethylene Ketones. Part 22. 2H,5H-(1)Benzothiopyrano(4,3-b)pyran Derivatives with Platelet Antiaggregating Activity.

The synthesis of some N,N-disubstituted 4-amino-3-phenyl-2H,5H-[1]benzothiopyrano [4,3-b]pyran-2-ones by reaction of phenylchloroketene with a series of N,N-disubstituted 3-aminomethylene-2,3-dihydro-4H-1-benzothiopyran-4-ones, followed by dehydrochlorination of the primary adducts with DBN, is described. Some of these compounds showed a strong platelet antiaggregating activity in vitro, superior to that of acetylsalicylic acid.

Amides of N-phenyl benzonorbornen-2-endo-amine with hypotensive and other activities.

The synthesis of two series of amides and glycinamides starting from N-phenyl benzonorbornen-2-endo-amine, prepared from benzonorbornen-2-one via sodium borohydride reduction of its N-phenyl imine, is described. Some amides showed a remarkable hypotensive activity in rats, whereas amides and glycinamides usually exhibited a moderate infiltration anesthesia in mice. Effects on heart rate in rats and antiarrhythmic activity in mice are also reported.

2- And 5-substituted 5-amino-2,6,6-trimethyltetrahydropyrans

Reaction of N,N-disubstituted 2-carboxyamido-2,6,6-trimethyltetrahydropyran-5-carboxylic acids with diphenyl phosphorazide in the presence of triethylamine and benzyl alcohol gave N,N-disubstituted 5-benzyloxycarbonylamino-2-carboxyamido-2,6,6-trimethyltetrahydr-pyrans, which in turn yielded N,-disubstituted 2-aminomethyl-5-methylamino-2,6,6-trimethyltetrahydropyrans by LiA1H4 reduction. 5-Benzyloxycarbonylamino-2-carboxypyrrolidino-2,6,6-trimethyltetrahydropyran gave 5-amino-2,6,6-trimethyl-2--pyrrolidinomethyltetrahydropyran by hydrogenolysis followed by LiA1H4 reduction. Among the amides prepared from the latter, the diphenylacetic acid amide showed antiarrhythmic and local-anesthetic activity.