2-methylsulfanyl-5,6-dihydro-4H-1,3-thiazine

Conditions: temp:0.00; pressure:0.00; stir:

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

Procedure: To a mixture of 235 g of 5,6-dihydro-2-(methylthio)-4H-1,3-thiazine (A. F. McKay et al., J. Am. Chem. Soc., 80, 3339 (1950)) and 2 g of zinc chloride at approximately 115° in a nitrogen atmosphere, 263 g of ethyl nitroacetate (S. Zen et al., Kogyo Kagaku Zosshi, 74, 70 (1971)) was added dropwise over a 1.5 hour period. The mixture was held at 110°-120°. When evolution of methyl mercaptan ceased after 45 minutes further stirring of the heated mixture, 1 g of zinc chloride was added and the mixture was stirred at about 115° for 1.25 hours. An additional 1 g of zinc chloride then was added and stirring of the mixture at about 115° was continued for 1.5 hours. The mixture then was poured into a cooled 2/1 ether/isopropyl alcohol mixture. The crystallized product was collected, washed with ether and dried under reduced pressure to leave a tan solid, m.p. 100° -102°, which on recrystallization from methanol gave ethyl nitro(tetrahydro-2H-1,3-thiazin-2-ylidene)acetate (5A), as a pale yellow solid, m.p. 105°-106°. was held at 110°-120° was added stirring of the mixture at about 115° was continued for 1.5 hours The mixture then was poured into The crystallized product was collected washed with ether dried under reduced pressure to leave a tan solid, m.p. 100° -102°, which on recrystallization from methanol

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

Procedure: To a mixture of 235 g of 5,6-dihydro-2-(methylthio)-4H-1,3-thiazine and 2 g of zinc chloride at approximately 115° in a nitrogen atmosphere, 263 g of ethyl nitroacetate was added dropwise over a 1.5 hour period. The mixture was held at 110°-120°. When evolution of methyl mercaptan ceased after 45 minutes further stirring of the heated mixture, 1 g of zinc chloride was added and the mixture was stirred at about 115° for 1.25 hours. An additional 1 g of zinc chloride then was added and stirring of the mixture at about 115° was continued for 1.5 hours. The mixture then was poured into a cooled solution of 2/1 ether/isopropyl alcohol mixture. The crystallized product was collected, washed with ether and dried under reduced pressure to leave a tan solid, m.p. 100°-102°, which on recrystallization from methanol gave ethyl nitro(tetrahydro-2H-1,3-thiazin-2-ylidene)acetate (1A) as a pale yellow solid, m.p. 105°-106°. was added dropwise over a 1.5 hour period was held at 110°-120° was added stirring of the mixture at about 115° was continued for 1.5 hours The crystallized product was collected washed with ether dried under reduced pressure to leave a tan solid, m.p. 100°-102°, which on recrystallization from methanol

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

Procedure: To a mixture of 235 g of 5,6-dihydro-2-(methylthio)-4H-1,3-thiazine and 2 g of zinc chloride at approximately 115° in a nitrogen atmosphere, 263 g of ethyl nitroacetate was added dropwise over a 1.5 hour period. The mixture was held at 110°-120°. When evolution of methyl mercaptan ceased after 45 minutes further stirring of the heated mixture, 1 g of zinc chloride was added and the mixture was stirred at about 115° for 1.25 hours. An additional 1 g of zinc chloride then was added and stirring of the mixture at about 115° was continued for 1.5 hours. The mixture then was poured into a cooled solution of 2/1 ether/isopropyl alcohol mixture. The crystallized product was collected, washed with ether and dried under reduced pressure to leave a tan solid, m.p. 100°-102°, which on recrystallization from methanol gave ethyl nitro(tetrahydro-2H-1,3-thiazin-2-ylidene)acetate (1A) as a pale yellow solid, m.p. 105°-106°. was added dropwise over a 1.5 hour period was held at 110°-120° was added stirring of the mixture at about 115° was continued for 1.5 hours The crystallized product was collected washed with ether dried under reduced pressure to leave a tan solid, m.p. 100°-102°, which on recrystallization from methanol

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

Procedure: To a mixture of 235 g of 5,6-dihydro-2-(methylthio)-4H-1,3-thiazine (A. F. McKay et al., J. Am. Chem. Soc., 80, 3339 (1958)) and 2 g of zinc chloride at approximately 115° in a nitrogen atmosphere, 263 g of ethyl nitroacetate (S. Zen, et al., Kogyo Kagaku Zasshi, 74, 70 (1971)) was added dropwise over a 1.5 hour period. The mixture was held at 110°-120°. When evolution of methyl mercaptan ceased after 45 minutes further stirring of the heated mixture, 1 g of zinc chloride was added and the mixture was stirred at about 115° for 1.25 hours. An additional 1 g of zinc chloride then was added and stirring of the mixture at about 115° was continued for 1.5 hours. The mixture then was poured into a cooled solution of 2/1 (volume) ether/isopropyl alcohol mixture. The crystallized product was collected, washed with ether and dried under reduced pressure to leave a tan solid, m.p. 100° -102°, which on recrystallization from methanol gave ethyl nitro(tetrahydro-2H-1,3-thiazin-2-ylidene)acetate (1A) as a pale yellow solid, m.p. 105° -106°. was held at 110°-120° was added stirring of the mixture at about 115° was continued for 1.5 hours The crystallized product was collected washed with ether dried under reduced pressure to leave a tan solid, m.p. 100° -102°, which on recrystallization from methanol

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

Procedure: To a mixture of 235 g of 5,6-dihydro-2-(methylthio)-4H-1,3-thiazine (A. F. McKay et al., J. Am. Chem. Soc., 80, 3339 (1958)) and 2 g of zinc chloride at approximately 115° in a nitrogen atmosphere, 263 g of ethyl nitroacetate (S. Zen, et al., Kogyo Kagaku Zasshi, 74, 70 (1971)) was added dropwise over a 1.5 hour period. The mixture was held at 110°-120°. When evolution of methyl mercaptan ceased after 45 minutes further stirring of the heated mixture, 1 g of zinc chloride was added and the mixture was stirred at about 115° for 1.25 hours. An additional 1 g of zinc chloride then was added and stirring of the mixture at about 115° was continued for 1.5 hours. The mixture then was poured into a cooled solution of 2/1 (volume) ether/isopropyl alcohol mixture. The crystallized product was collected, washed with ether and dried under reduced pressure to leave a tan solid, m.p. 100° -102°, which on recrystallization from methanol gave ethyl nitro(tetrahydro-2H-1,3-thiazin-2-ylidene)acetate (1A) as a pale yellow solid, m.p. 105° -106°. was held at 110°-120° was added stirring of the mixture at about 115° was continued for 1.5 hours The crystallized product was collected washed with ether dried under reduced pressure to leave a tan solid, m.p. 100° -102°, which on recrystallization from methanol

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

Procedure: To a mixture of 235 g of 5,6-dihydro-2-(methylthio)-4H-1,3-thiazine (A. F. McKay et al., J. Am. Chem. Soc., 80, 3339 (1950)) and 2 g of zinc chloride at approximately 115° in a nitrogen atmosphere, 263 g of ethyl nitroacetate (S. Zen et al., Kogyo Kagaku Zosshi, 74, 70 (1971)) was added dropwise over a 1.5 hour period. The mixture was held at 110°-120°. When evolution of methyl mercaptan ceased after 45 minutes further stirring of the heated mixture, 1 g of zinc chloride was added and the mixture was stirred at about 115° for 1.25 hours. An additional 1 g of zinc chloride then was added and stirring of the mixture at about 115° was continued for 1.5 hours. The mixture then was poured into a cooled 2/1 ether/isopropyl alcohol mixture. The crystallized product was collected, washed with ether and dried under reduced pressure to leave a tan solid, m.p. 100°-102°, which on recrystallization from methanol gave ethyl nitro(tetrahydro-2H-1,3-thiazin-2-ylidene)acetate as a pale yellow solid, m.p. 105°-106°. was held at 110°-120° was added stirring of the mixture at about 115° was continued for 1.5 hours The mixture then was poured into The crystallized product was collected washed with ether dried under reduced pressure to leave a tan solid, m.p. 100°-102°, which on recrystallization from methanol

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

Procedure: To a mixture of 235 g of 5,6-dihydro-2-(methylthio)-4H-1,3-thiazine and 2 g of zinc chloride at approximately 115° in a nitrogen atmosphere, 263 g of ethyl nitroacetate was added dropwise over a 1.5 hour period. The mixture was held at 110°-120° and the nitrogen atmosphere was maintained during the addition. Evolution of methyl mercaptan ceased after 45 minutes of stirring of the heated mixture when 1 g of zinc chloride was added to the stirred mixture at ca. 115°. After 1.25 hours an additional 1 g of zinc chloride was added and stirring of the mixture at ca. 115° was continued for 1.5 hours. The mixture then was poured into a cooled solution of 2/1 ether/isopropyl alcohol mixture. The crystallized product was collected, washed with ether and dried under reduced pressure to leave a tan solid which on recrystallization from methanol gave 2a as a pale yellow solid, m.p.: 105°-106°. was added dropwise over a 1.5 hour period was held at 110°-120° the nitrogen atmosphere was maintained during the addition was added to the stirred mixture at ca. 115° The crystallized product was collected washed with ether dried under reduced pressure to leave a tan solid which on recrystallization from methanol

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

Procedure: A mixture of 3.3 g of 2-nitroacetophenone and 2.94 g of 2-(methylthio)-5,6-dihydro-4H-1,3-thiazine was heated to 115° and 100 milligrams of zinc chloride was added. Heating and stirring was continued at 115°-120° for 2.5 hours. After cooling, the mixture was filtered (with the aid of ethyl acetate) through a short column of florosil to give an amber oil. The oil was chromatographed on silica gel using dry-column technique and a 1:1:2 mixture of tetrahydrofuran/ethyl acetate/hexane for development to give 1 as a salmon-colored solid, m.p.: 137°-140°. was heated to 115° Heating After cooling the mixture was filtered (with the aid of ethyl acetate) through a short column of florosil to give an amber oil The oil was chromatographed on silica gel using dry-column technique a 1:1:2 mixture of tetrahydrofuran/ethyl acetate/hexane for development

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

Procedure: A mixture of 3.3 g of 2-nitroacetophenone and 2.94 g of 2-(methylthio)-5,6-dihydro-4H-1,3-thiazine was heated to 115° and 100 milligrams of zinc chloride was added. Heating and stirring was continued at 115°-120° for 2.5 hours. After cooling, the mixture was filtered (with the aid of ethyl acetate) through a short column of florosil to give an amber oil. The oil was chromatographed on silica gel using dry-column technique and a 1:1:2 mixture of tetrahydrofuran/ethyl acetate/hexane for development to give 1 as a salmon-colored solid, m.p.: 137°-140°. was heated to 115° Heating After cooling the mixture was filtered (with the aid of ethyl acetate) through a short column of florosil to give an amber oil The oil was chromatographed on silica gel using dry-column technique a 1:1:2 mixture of tetrahydrofuran/ethyl acetate/hexane for development

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

Procedure: To a mixture of 235 g of 5,6-dihydro-2-(methylthio)-4H-1,3-thiazine and 2 g of zinc chloride at approximately 115° in a nitrogen atmosphere, 263 g of ethyl nitroacetate was added dropwise over a 1.5 hour period. The mixture was held at 110°-120°. When evolution of methyl mercaptan ceased after 45 minutes further stirring of the heated mixture, 1 g of zinc chloride was added and the mixture was stirred at about 115° for 1.25 hours. An additional 1 g of zinc chloride then was added and stirring of the mixture at about 115° was continued for 1.5 hours. The mixture then was poured into a cooled solution of 2/1 ether/isopropyl alcohol mixture. The crystallized product was collected, washed with ether and dried under reduced pressure to leave a tan solid, m.p. 100°-102°, which on recrystallization from methanol gave 2A as a pale yellow solid, m.p. 105°-106°. was added dropwise over a 1.5 hour period was held at 110°-120° was added stirring of the mixture at about 115° was continued for 1.5 hours The crystallized product was collected washed with ether dried under reduced pressure to leave a tan solid, m.p. 100°-102°, which on recrystallization from methanol

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

Procedure: To a mixture of 235 g of 5,6-dihydro-2-(methylthio)-4H-1,3-thiazine and 2 g of zinc chloride at approximately 115° in a nitrogen atmosphere, 263 g of ethyl nitroacetate was added dropwise over a 1.5 hour period. The mixture was held at 110°-120°. When evolution of methyl mercaptan ceased after 45 minutes further stirring of the heated mixture, 1 g of zinc chloride was added and the mixture was stirred at about 115° for 1.25 hours. An additional 1 g of zinc chloride then was added and stirring of the mixture at about 115° was continued for 1.5 hours. The mixture then was poured into a cooled solution of 2/1 ether/isopropyl alcohol mixture. The crystallized product was collected, washed with ether and dried under reduced pressure to leave a tan solid, m.p. 100°-102°, which on recrystallization from methanol gave 2A as a pale yellow solid, m.p. 105°-106°. was added dropwise over a 1.5 hour period was held at 110°-120° was added stirring of the mixture at about 115° was continued for 1.5 hours The crystallized product was collected washed with ether dried under reduced pressure to leave a tan solid, m.p. 100°-102°, which on recrystallization from methanol