Abstract: Novel water soluble dyes of the formula I are provided ##STR1## wherein R.sup.1 and R.sup.4 are alkyl of 1 to 4 carbon atoms or hydrogen; or R.sup.1 -R.sup.2 or R.sup.2 -R.sup.4 form part of aliphatic heterocyclic rings; R.sup.2 is hydrogen or joined with R.sup.1 or R.sup.4 as described above; R.sup.3 is --(CH.sub.2).sub.m --SO.sub.3.sup.-, where m is 1 to 6;X is N, CH or ##STR2## where Y is 2 --SO.sub.3.sup.- ; Z is 3, 4, 5 or 6 --SO.sub.3.sup.-. The novel dyes are particularly useful as the active media in water solution dye lasers.

Abstract: Methods for the efficient preparation of 7-hydroxy-1,2,3,4-tetrahydroquinoline include a first method in which the acylation of m-aminophenol obtains a lactam which is reduced to give the desired quinoline and a second method in which tetrahydroquinoline is nitrated and hydrogenated and then hydrolyzed to obtain the desire quinoline. 7-hydroxy-1,2,3,4-tetrahydroquinoline is used in the efficient synthesis of four lasing dyes of the rhodamine class.

Abstract: A novel method for the synthesis of 6-hydroxyindolines and new fluorescent dyes produced therefrom, which dyes are ring-constrained indoline-based rhodamine class dyes. These dyes have absorption and emission spectra which make them particularly useful in certain dye laser applications.

Abstract: New oxazine compounds useful as dye laser media in solution, are superiior to prior art materials. The oxazine dyes useful when pumped by the 578.

Abstract: A novel class of dye is disclosed which is particularly efficient and stable for dye laser applications, lasing between 540 and 570 nm.

Abstract: A novel class of dye is disclosed which is particularly efficient and stable for dye laser applications, lasing between 540 and 570 nm.

Abstract: A dye of the DCM family, [2-methyl-6-[2-(1,2,3,4-tetrahydro-1-methyl-6-quinolinyl)ethenyl]-4H-pyran -4-ylidene]-propanedinitrile, dissolved in 2-phenoxyethanol, is non-mutagenic, stable and efficient, particularly in a pumped continuous wave laser system.

Abstract: A novel class of dye is disclosed which is particularly efficient and stable for dye laser applications, lasing between 540 and 570 nm.

Abstract: A novel class of dye is disclosed which is particularly efficient and stable for dye layer applications, lasing between 540 and 570 nm.

Abstract: Methods are provided for making certain m-aminophenols using a sulfonation/alkali fusion procedure. The aminophenols are key intermediates in the synthesis of dyes, particularly efficient, stable dyes for laser application. Preparations of some rhodamine and phenoxazone dyes from the m-aminophenols are described.

Abstract: Compounds having the formula: ##STR1## wherein X is selected from the group consisting of NH and O, R is selected from the group consisting of H, CH.sub.3 and phenyl, R' is selected from the group consisting of OCH.sub.3, CF.sub.3 CH.sub.3 and H and R" is selected from the group consisting of H, CH.sub.3 and CH.sub.2 CO.sub.2 C.sub.2 H.sub.5. The compounds are stable, efficient laser dyes.

Abstract: 2-Keto-6,7,8,9-tetrahydro-2H-pyrano(3,2-g)-quinoline and 2-keto-9-methyl-,8,9-tetrahydro-2H-pyrano(3,2-g)-quinoline, compounds useful as laser dyes, are prepared from 7-hydroxy-1,2,3,4-tetrahydroquinoline.

Abstract: A dye laser comprising a laser dye solution of a compound having the general structure: ##STR1## wherein at least one of the 5, 6 and 8 ring positions is occupied by a nitrogen atom in lieu of the corresponding CR group and X is OH, alkoxy, or amino including amino substituted by at least one of the following: alkyl, aryl, acyl, aracyl, a group which taken together with the nitrogen atom of the amino group forms a heterocyclic ring, or part of one or two 5 or 6 membered aliphatic heterocyclic rings attached to ring A at positions 6 or 8 or both depending on where the N in ring A is located. R.sub.1, R.sub.3, R.sub.4, R.sub.5, R.sub.6 and R.sub.8 are hydrogen or other groups as defined below. The compounds lase in the blue to near ultraviolet region.

Abstract: A dye laser comprising a laser dye solution of a compound having the general structure: ##STR1## wherein at least one of the 5, 6 and 8 ring positions is occupied by a nitrogen atom in lieu of the corresponding CR group and X is OH, alkoxy, or amino including amino substituted by at least one of the following: alkyl, aryl, acyl, aracyl, a group which taken together with the nitrogen atom of the amino group forms a heterocyclic ring, or part of one or two 5 or 6 membered aliphatic heterocyclic rings attached to ring A at positions 6 or 8 or both depending on where the N in ring A is located. R.sub.3, R.sub.4, R.sub.5, R.sub.6 and R.sub.8 are hydrogen or other groups as defined below. The compounds lase in the blue-green to near ultraviolet region.

Abstract: Methods for preparing ##STR1## wherein n is 3 or 4 and R is H, CH.sub.3 or C.sub.2 H.sub.5. The methods involve forming ##STR2## by reacting p-terphenyl or quaterphenyl with acetic acid and fuming nitric acid, forming ##STR3## by refluxing the dinitro derivative with stannous chloride, hydorchloric acid and acetic acid and forming the dialkylamino derivative by refluxing the diamino derivatives with a suitable trialkyl phosphate. Also, ##STR4## derivatives may be prepared by refluxing the diamino derivatives with sodium nitrite and hydrochloric acid to form ##STR5## AND REACTING THIS INTERMEDIATE WITH A MIXTURE OF ACETIC ACID AND EITHER WATER OR ALCOHOL. The compounds are useful as lasing dyes.

Abstract: 7-Amino coumarin dyes with hydrocarbon substituents on the amino group, but otherwise unsubstituted are stable, efficient dyes which lase in the blue-green region in a flashlamp-pumped dye laser.

Abstract: 7-Oxo-1,2,3,3,8-pentamethyl-5-trifluoromethyl-2,3,7,8-tetrahydro-1-H-pyrrol 3,2-g] quinoline, a new compound, useful as a blue-green laser dye, is prepared from a substituted indole.

Abstract: Methods for preparing 2,6-bis(dimethylamino)pyridine and 2,6-bis(methylamino)pyridine are disclosed. The methods involve the reaction of 2,6-dichloropyridine with an aqueous solution of either dimethylamine or methylamine, in the presence of copper sulfate for 15 hours in a bomb at 160.degree.C. The compounds synthesized are useful as lasing dyes.

Abstract: 1,4-Bis(5-p-n-butoxyphenyloxazol-2-yl)-benzene is prepared. The compound is seful as a lasing dye.

Abstract: A dye laser having a high frequency rate of modulation wherein a Franz-Kesh filter is in the laser cavity to quench Q, and thereby provide modulation. The filter has an absorption edge that shifts in response to an applied electric field, thereby, modulating the laser beam.