2,3,4,5,6-pentachlorobenzenethiol

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Detection and Quantification of Methamphetamine using a Reactive Coating on Silver Foil: Silver foil was roughened and etched (Example 1d) followed by dip-coating in an methanol solution of MNA/methamphetamine containing 2 ppm of a CH2Cl2 solution of pentachlorothiolphenol (PCTP). The PCTP was used as an internal standard for quantification purposes. The coated foil surfaces were rinsed with ethanol to remove unbound MNA/methamphetamine and PCTP. The MNA/methamphetamine was synthesized by dissolving 186 mg methamphetamine hydrochloride in 15 mL of saturated aqueous K2CO3 to neutralize the hydrochloride. The freebase was then extracted from the aqueous solution using diethyl ether (Et2O). The ether was removed under reduced pressure and the methamphetamine re-dissolved in 8 mL of ethanol to which was added 169 mg 2-mercaptonicotinic acid (MNA) and 228 mg dicyclohexylcarbodiimide (DCC) in 2mL H2O. The reaction was gently refluxed under a nitrogen atmosphere for 2 hr. The MNA/methamphetamine reaction product was transferred to a separatory funnel using Et2O and extracted with additional Et2O followed by washes with saturated aqueous NaHCO3, H2O, and 10% HCI. Solvent was removed under reduced pressure. The product N-methyl-N-(1-methyl-2-phenylethyl)-2-mercaptopyridine-3-carboxamide (MNA/methamphetamine) was re-dissolved in methanol to form standard solutions in the concentration range of 0 ppm to 2500 ppm. SERS spectra were obtained from the MNA/methamphetamine/PCTP coated silver foil surfaces. The coated foil surfaces were rinsed with ethanol to remove unbound MNA/methamphetamine and PCTP The freebase was then extracted from the aqueous solution The ether was removed under reduced pressure the methamphetamine re-dissolved in 8 mL of ethanol to which was added 169 mg 2-mercaptonicotinic acid (MNA) and 228 mg dicyclohexylcarbodiimide (DCC) in 2mL H2O The reaction was gently refluxed under a nitrogen atmosphere for 2 hr The MNA/methamphetamine reaction product was transferred to a separatory funnel extracted with additional Et2O Solvent was removed under reduced pressure The product N-methyl-N-(1-methyl-2-phenylethyl)-2-mercaptopyridine-3-carboxamide (MNA/methamphetamine) was re-dissolved in methanol to form standard solutions in the concentration range of 0 ppm to 2500 ppm

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Detection and Quantification of Amphetamine using a Reactive Coating on Silver Foil: Silver foil was roughened and etched (Example 1d) followed by dip-coating in an CH2Cl2 solution of MNA/amphetamine containing 3 ppm of a CH2Cl2 solution of pentachlorothiolphenol (PCTP). The PCTP was used as an internal standard for quantification purposes. The coated foil surfaces were rinsed with ethanol to remove unbound MNA/amphetamine and PCTP. The MNA/amphetamine was synthesized by dissolving 363 mg amphetamine sulfate in 10 mL of an aqueous saturated solution of K2CO3 to neutralize the sulfate. The freebase drug was then extracted from the aqueous solution using CH2Cl2 followed by addition of 155 mg 2-mercaptonicotinic acid (MNA) and 206 mg dicyclohexylcarbodiimide (DCC). The reaction was gently refluxed overnight under a nitrogen atmosphere. The MNA/amphetamine reaction product was transferred to a separatory funnel with CH2Cl2 and washed with an aqueous saturated solution of NaHCO3 to neutralize unreacted MNA, followed by a wash with H2O and 10% HCI to neutralize unreacted freebase and DCC. Solvent was removed under reduced pressure. The product N-(1-methyl-2-phenylethyl)-2-mercaptopyridine-3-carboxamide (MNA/amphetamine) was re-dissolved in CH2Cl2 to form standard solutions in the concentration range of 0 ppm to 500 ppm. SERS spectra were obtained from the MNA/amphetamine/PCTP coated silver foil surfaces. The coated foil surfaces were rinsed with ethanol to remove unbound MNA/amphetamine and PCTP The freebase drug was then extracted from the aqueous solution followed by addition of 155 mg 2-mercaptonicotinic acid (MNA) and 206 mg dicyclohexylcarbodiimide (DCC) The MNA/amphetamine reaction product washed with an aqueous saturated solution of NaHCO3 a wash with H2O and 10% HCI Solvent was removed under reduced pressure The product N-(1-methyl-2-phenylethyl)-2-mercaptopyridine-3-carboxamide (MNA/amphetamine) was re-dissolved in CH2Cl2 to form standard solutions in the concentration range of 0 ppm to 500 ppm

Conditions: temp:55.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Pentachlorothiophenol (10.0 g, 0.035 mol) was added to 60.0 g of 99% nitric acid over 20 min at 45°-50° C. followed by heating at reflux (55° C.) for 1.5 hr. At this point 20 mL of 30% by weight oleum was added at such a rate that the temperature was kept at 75° to 80° C. After the addition was complete (approximately 30 min.), the reaction mixture was cooled to room temperature. The product was collected by filtration, and thoroughly washed with water to give after drying in vacuo, 8.6 g (85% yield) of 99.7% PCNB with 0.17% hexachlorobenzene (GC assay). Variations on this one-pot, two-step process were examined and are summarized in TABLE I. by heating was kept at 75° to 80° C After the addition (approximately 30 min.) the reaction mixture was cooled to room temperature The product was collected by filtration thoroughly washed with water to give

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Pentachlorothiophenol (10.0 g, 0.035 mol) was added to 60.0 g of 70% nitric acid at room temperature. The reaction mixture was heated at reflux 7 hr followed by stirring at room temperature 16 hr. At this point, 40 mL of 30% oleum (30% by weight sulfur trioxide in sulfuric acid) was added at such a rate that the temperature was maintained between 55° and 60° C. After the addition was complete (30 min), the reaction mixture was heated at 108° C. for 30 minutes. The reaction mixture was then cooled to room temperature, filtered, the product washed with water and dried in vacuo to give 7.6 g (74% yield) of 99.0% PCNB with 1.0% hexachlorobenzene (GC assay). The reaction mixture was heated at reflux 7 hr was maintained between 55° and 60° C After the addition (30 min) the reaction mixture was heated at 108° C. for 30 minutes The reaction mixture was then cooled to room temperature filtered the product washed with water dried in vacuo

Conditions: temp:85.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Hexachlorobenzene (25.0 g, 0.088 mol) was added to 50 mL of dimethylformamide followed by the addition of 7.4 g (0.096 mol) of 73% sodium hydrosulfide and 7.9 mL (0.079 mol) of 40% aqueous sodium hydroxide. The stirred reaction mixture was heated to 85° C. for 3.0 hr, cooled to room temperature, and poured into 200 mL of water. After 10 min of stirring, the insoluble material was removed by filtration, and the filtrate acidified with 15 mL (0.18 mol) of concentrated aqueous hydrochloric acid. The resulting precipitate was collected by filtration, washed with 100 mL of water, and dried in vacuo giving 22.8 g, 92% of theoretical, of pentachlorothiophenol. The stirred reaction mixture cooled to room temperature the insoluble material was removed by filtration The resulting precipitate was collected by filtration washed with 100 mL of water dried in vacuo

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: reacting this sodium salt of pentachlorothiophenol with a mixed nitration acid comprising nitric acid and sulfuric acid (and, preferably, sulfur trioxide to form oleum) at a temperature from about 35° C. to about 110° C. to form pentachloronitrobenzene, the nitric acid being in molar excess of the pentachlorothiophenol.

Conditions: temp:55.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Pentachlorothiophenol (10.0 g, 0.035 mol) was added to 60.0 g of 99% nitric acid over 20 min at 45°-50° C. followed by heating at reflux (55° C.) for 1.5 hr. At this point 20 mL of 30% by weight oleum was added at such a rate that the temperature was kept at 75° to 80° C. After the addition was complete (approximately 30 min.), the reaction mixture was cooled to room temperature. The product was collected by filtration, and thoroughly washed with water to give after drying in vacuo, 8.6 g (85% yield) of 99.7% PCNB with 0.17% hexachlorobenzene (GC assay). Variations on this one-pot, two-step process were examined and are summarized in TABLE I. by heating was kept at 75° to 80° C After the addition (approximately 30 min.) the reaction mixture was cooled to room temperature The product was collected by filtration thoroughly washed with water to give

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Pentachlorothiophenol (10.0 g, 0.035 mol) was added to 60.0 g of 70% nitric acid at room temperature. The reaction mixture was heated at reflux 7 hr followed by stirring at room temperature 16 hr. At this point, 40 mL of 30% oleum (30% by weight sulfur trioxide in sulfuric acid) was added at such a rate that the temperature was maintained between 55° and 60° C. After the addition was complete (30 min), the reaction mixture was heated at 108° C. for 30 minutes. The reaction mixture was then cooled to room temperature, filtered, the product washed with water and dried in vacuo to give 7.6 g (74% yield) of 99.0% PCNB with 1.0% hexachlorobenzene (GC assay). The reaction mixture was heated at reflux 7 hr was maintained between 55° and 60° C After the addition (30 min) the reaction mixture was heated at 108° C. for 30 minutes The reaction mixture was then cooled to room temperature filtered the product washed with water dried in vacuo

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: reacting pentachlorothiophenol (PCTP) with a mixed nitration acid comprising nitric acid and sulfuric acid (and, preferably, sulfur trioxide to form oleum) at a temperature from about 35° to about 110° C. to form pentchloronitrobenzene, the nitric acid being in molar excess of the pentachlorothiophenol.