1-(3,4-dihydroxyphenyl)propan-1-one

Conditions: temp:170.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of 3,4-dihydroxypropiophenone (ICN Biomedicals, Inc., 3300 Hyland Ave., Costa Mesa, Calif., 92626, USA, 5.0 g, 30 mmol) and dichlorodiphenylmethane (10.0 mL, 52.1 mmol) was heated for 7 min at 170° C. The reaction was cooled and poured into 1 N sodium hydroxide. The mixture was extracted with ether (2×) and the combined extracts were washed with water and brine. The organic layer was dried over magnesium sulfate and concentrated. The residue was flash chromatographed on silica gel (2×5 inches packed in hexane) with elution proceeding as follows: 2% ether/hexane (500 mL), 0.84 g of a white solid tentatively identified as 2-chloro-1-(2,2-diphenyl-benzo(1,3)dioxol-5-yl)-propan-1-one; 5% ether/hexane (250 mL), 1.9 g of an unidentified orange oil; 5% ether/hexane (250 mL), 2.18 g of recovered dichlorodiphenylmethane; 10% ether/hexane (500 mL), 4.82 g (48%) of 1-(2,2-diphenyl-benzo(1,3)dioxol-5-yl)-propan-1-one as an orange oil which solidified on standing. The product had: mp 69-70.5° C. Analysis calculated for C22H17ClO3 : C, 79.98; H, 5.49. Found: C, 80.05; H, 5.34. The reaction was cooled The mixture was extracted with ether (2×) the combined extracts were washed with water and brine The organic layer was dried over magnesium sulfate concentrated chromatographed on silica gel (2×5 inches packed in hexane) with elution proceeding

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

Procedure: 3',4'-Bis(pivaloyloxy)propiophenone was first prepared as a mobile liquid (63.6 g.), in a similar manner to 3',4'-bis(pivaloyloxy)acetophenone in Example 1, starting from 3',4'-dihydroxypropiophenone (40 g.), pivaloylchloride (63.3 ml.) and triethylamine (73.2 ml.). This mobile liquid (40.1 g.) was then reacted with bromine (7.2 ml.) in a similar manner to that used in Example 1 to obtained 2-bromo-3',4'-bis(pivaloyloxy)acetophenone. The crude bromo compound thus obtained was purified by dry column chromatography on silica gel as described in Example 1 to give pure 2-bromo-3',4'-bis(pivaloyloxy)propiophenone as a solid (18.4 g.), m.p. 58°-60° C.

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

Procedure: 3',4'-Bis(pivaloyloxy)propiophenone was first prepared as a mobile liquid (63.6 g.), in a similar manner to 3',4'-bis(pivaloyloxy)acetophenone in Example 1, starting from 3',4'-dihydroxypropiophenone (40 g.), pivaloylchloride (63.3 ml.) and triethylamine (73.2 ml.). This mobile liquid (40.1 g.) was then reacted with bromine (7.2 ml.) in a similar manner to that used in Example 1 to obtained 2-bromo-3',4'-bis(pivaloyloxy)acetophenone. The crude bromo compound thus obtained was purified by dry column chromatography on silica gel as described in Example 1 to give pure 2-bromo-3',4'-bis(pivaloyloxy)propiophenone as a solid (18.4 g.), m.p. 58°-60° C.

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

Procedure: 3',4'-Bis(pivaloyloxy)propiophenone was first prepared as a mobile liquid (63.6 g.), in a similar manner to 3',4'-bis(pivaloyloxy)acetophenone in Example 1, starting from 3', 4'-dihydroxypropiophenone (40 g.), pivaloylchloride (63.3 ml.) and triethylamine (73.2 ml.). This mobile liquid (40.1 g.) was then reacted with bromine (7.2 ml.) in a similar manner to that used in Example 1 to obtained 2-bromo-3',4'-bis(pivaloyloxy)acetophenone. The crude bromo compound thus obtained was purified by dry column chromatography on silica gel as described in Example 1 to give pure 2-bromo-3',4'-bis(pivaloyloxy)propiophenone as a solid (18.4 g), m.p. 58°-60° C.

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

Procedure: 3',4'-Bis(pivaloyloxy)propiophenone was first prepared as a mobile liquid (63.6 g.), in a similar manner to 3',4'-bis(pivaloyloxy)acetophenone in Example 1, starting from 3', 4'-dihydroxypropiophenone (40 g.), pivaloylchloride (63.3 ml.) and triethylamine (73.2 ml.). This mobile liquid (40.1 g.) was then reacted with bromine (7.2 ml.) in a similar manner to that used in Example 1 to obtained 2-bromo-3',4'-bis(pivaloyloxy)acetophenone. The crude bromo compound thus obtained was purified by dry column chromatography on silica gel as described in Example 1 to give pure 2-bromo-3',4'-bis(pivaloyloxy)propiophenone as a solid (18.4 g), m.p. 58°-60° C.

Conditions: temp:170.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of 3,4-dihydroxypropiophenone (ICN Biomedicals, Inc., 3300 Hyland Ave., Costa Mesa, Calif., 92626, USA, 5.0 g, 30 mmol) and dichlorodiphenylmethane (10.0 mL, 52.1 mmol) was heated for 7 min at 170° C. The reaction was cooled and poured into 1 N sodium hydroxide. The mixture was extracted with ether (2×) and the combined extracts were washed with water and brine. The organic layer was dried over magnesium sulfate and concentrated. The residue was flash chromatographed on silica gel (2×5 inches packed in hexane) with elution proceeding as follows: 2% ether/hexane (500 mL), 0.84 g of a white solid tentatively identified as 2-chloro-1-(2,2-diphenyl-benzo(1,3)dioxol-5-yl)-propan-1-one; 5% ether/hexane (250 mL), 1.9 g of an unidentified orange oil; 5% ether/hexane (250 mL), 2.18 g of recovered dichlorodiphenylmethane; 10% ether/hexane (500 mL), 4.82 g (48%) of 1-(2,2-diphenyl-benzo(1,3)dioxol-5-yl)-propan-1-one as an orange oil which solidified on standing. The product had: mp 69-70.5° C. Analysis calculated for C22H17CIO3: C, 79.98; H, 5.49. Found: C, 80.05; H, 5.34. The reaction was cooled The mixture was extracted with ether (2×) the combined extracts were washed with water and brine The organic layer was dried over magnesium sulfate concentrated chromatographed on silica gel (2×5 inches packed in hexane) with elution proceeding

Conditions: temp:170.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of 3,4-dihydroxypropiophenone (ICN Biomedicals, Inc., 3300 Hyland Ave., Costa Mesa, Calif., 92626, USA, 5.0 g, 30 mmol) and dichlorodiphenylmethane (10.0 mL, 52.1 mmol) was heated for 7 min at 170° C. The reaction was cooled and poured into 1 N sodium hydroxide. The mixture was extracted with ether (2×) and the combined extracts were washed with water and brine. The organic layer was dried over magnesium sulfate and concentrated. The residue was flash chromatographed on silica gel (2×5 inches packed in hexane) with elution proceeding as follows: 2% ether/hexane (500 mL), 0.84 g of a white solid tentatively identified as 2-chloro-1-(2,2-diphenyl-benzo(1,3)dioxol-5-yl)-propan-1-one; 5% ether/hexane (250 mL), 1.9 g of an unidentified orange oil; 5% ether/hexane (250 mL), 2.18 g of recovered dichlorodiphenylmethane; 10% ether/hexane (500 mL), 4.82 g (48%) of 1-(2,2-diphenyl-benzo(1,3)dioxol-5-yl)-propan-1-one as an orange oil which solidified on standing. The product had: mp 69-70.5° C. Analysis calculated for C22H17ClO3 : C, 79.98; H, 5.49. Found: C, 80.05; H, 5.34. The reaction was cooled The mixture was extracted with ether (2×) the combined extracts were washed with water and brine The organic layer was dried over magnesium sulfate concentrated chromatographed on silica gel (2×5 inches packed in hexane) with elution proceeding

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

Procedure: 3',4'-Bis(pivaloyloxy)propiophenone was first prepared as a mobile liquid (63.6 g.), in a similar manner to 3',4'-bis(pivaloyloxy)acetophenone in Example 1, starting from 3',4'-dihydroxypropiophenone (40 g.), pivaloylchloride (63.3 ml.) and triethylamine (73.2 ml.). This mobile liquid (40.1 g.) was then reacted with bromine (7.2 ml.) in a similar manner to that used in Example 1 to obtained 2-bromo-3',4'-bis(pivaloyloxy)acetophenone. The crude bromo compound thus obtained was purified by dry column chromatography on silica gel as described in Example 1 to give pure 2-bromo-3',4'-bis(pivaloyloxy)propiophenone as a solid (18.4 g.), m.p. 58°-60° C.