Methanol And Koh Reaction Lab Report

To the solution of methanol (50 ml) and KOH (1.1eq), carbon disulphide (1.1eq) was added slowly at room temperature. To the reaction mass, 2-aminophenol (1.eq) was added with stirring. The reaction mass was refluxed for 6 hr on water bath. Completion of the reaction was monitored by TLC. The reaction mixture was poured to a beaker containing ice cold water and acidified with glacial acetic acid (pH 6). The obtained solid was filtered, dried and recrystallized using ethanol to get the compound 1,3-benzoxazole-2-thiol 1.
The different derivatives of 1,3-benzoxazole-2-thiol were synthesized by similar method by using various 2-amino phenols.
Colour: white; IR (KBr, cm-1): 3386 cm-1 (-SH); 1H NMR (DMSO-d6, δ ppm): 7.3(s, H Ar-H),6.9(dd, H Ar-H),

The cold reaction mixture was stirred for 10 min and slowly POCl3 was added drop by drop to the cold solution. The reaction temperature was maintained to 00C and refluxed for 5 hr. The completion of reaction was checked by TLC. The reaction mass was poured onto crushed ice to get solid product. The obtained solid was filtered, dried and recrystallize using ethyl acetate to get compound 2-chloroquinoline-3-carbaldehyde

(iii) Synthesis of 13H benz[4’,5’]oxazole[2’,3’,:2,3][1,3]thiazino[6,5-b]quinolin-13-one 4 The compound 124 (0.01mol) was treated with 2-chloroquinoline-3-carbaldehyde 2 (0.01mol) in presence of DMF used as a solvent and refluxed for 8 hr. Then the reaction mixture was poured onto crushed ice. The solid product thus obtained was filtered, dried and recrystallized from ethanol to get compound 4. The compounds 5-15 have been prepared by following same procedure.
Colour: white; IR (KBr, cm-1): 1670 cm-1 (C=O); 1H NMR (DMSO-d6, δ ppm): 8.24(m, 2H Ar-H), 8.07(d, 2H Ar-H), 8.33(s, H Ar-H), 7.52(d, 2H Ar-H), 7.78(m, 2H Ar-H), 6.52(s, H -H); 13CNMR (DMSO-d6, δ ppm): 112-155(17C, Ar-C); 172(1C, C=O); M+,306.
(iv) Synthesis of 10-chloro-6aH,13Hbenz[4’,5’]oxazole[2’,3’,:2,3][1,3]thiazino[6,5b]quinolin-13-one 5
Colour: cream; IR (KBr, cm-1): 1672 cm-1 (C=O); 1H NMR (DMSO-d6, δ ppm): 8.37(s, H Ar-H), 8.02(dd, H Ar-H), 8.25(dd, H Ar-H), 7.88(s, H Ar-H), 7.68(d, 2H Ar-H), 7.29(m, 2H Ar-H), 6.59(s, H -H); 13C NMR (DMSO-d6, δ ppm): 115-158(17C, Ar-C), 178(1C, C=O); M+,340,