4-azido-2,3,5,6-tetrafluorobenzaldehyde

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

Procedure: To a stirred solution of 4-azido-2,3,5,6-tetrafluorobenzaldehyde (23), 0.140 g, 0.640 mmol) and 1-methylpiperidine-4-one (0.040 mL, 0.32 mmol) in MeOH (1.5 mL), 1N aq. NaOH (0.650 mL, 0.650 mmol) was added dropwise. Yellow suspension resulted within minutes which was stirred at rt for forty-five minutes and diluted with water (3 mL). Yellow solid was collected by vacuum filtration, washed with water until the filtrate was neutral to pH paper. The yellow solid was dried further in vacuo to give 0.139 g (83%) 3,5-bis(4'-azido-2',3',5',6'-tetrafluorophenylmethylene)-1-methyl piperidine-4-one (22) as bright yellow powder; mp 153° C. (violent decomposition). 1HNMR(CDCL3 δ 2.37 (s, 3H), 3.42 (s, 4H), 7.55 (s,2H). ##STR28## Yellow suspension resulted within minutes which Yellow solid was collected by vacuum filtration washed with water until the filtrate The yellow solid was dried further in vacuo

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

Procedure: To a stirred solution of 4-azido-2,3,5,6-tetrafluorobenzaldehyde (23), 0.140 g, 0.640 mmol) and 1-methylpiperidine-4-one (0.040 mL, 0.32 mmol) in MeOH (1.5 mL), 1N aq. NaOH (0.650 mL, 0.650 mmol) was added dropwise. Yellow suspension resulted within minutes which was stirred at rt for forty-five minutes and diluted with water (3 mL). Yellow solid was collected by vacuum filtration, washed with water until the filtrate was neutral to pH paper. The yellow solid was dried further in vacuo to give 0.139 g (83%) 3,5-bis(4'-azido-2',3',5',6'-tetrafluorophenylmethylene)-1-methyl piperidine-4-one (22) as bright yellow powder; mp 153° C. (violent decomposition). 1HNMR(CDCL3 δ 2.37 (s, 3H), 3.42 (s, 4H), 7.55 (s,2H). ##STR28## Yellow suspension resulted within minutes which Yellow solid was collected by vacuum filtration washed with water until the filtrate The yellow solid was dried further in vacuo

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

Procedure: To a stirred solution of 4-azido-2,3,5,6-tetrafluorobenzaldehyde (23), 0.140 g, 0.640 mmol) and 1-methylpiperidine-4-one (0.040 mL, 0.32 mmol) in MeOH (1.5 mL), 1N aq. NaOH (0.650 mL, 0.650 mmol) was added dropwise. Yellow suspension resulted within minutes which was stirred at rt for forty-five minutes and diluted with water (3 mL). Yellow solid was collected by vacuum filtration, washed with water until the filtrate was neutral to pH paper. The yellow solid was dried further in vacuo to give 0.139 g (83%) 3,5-bis(4'-azido-2',3',5',6'-tetrafluorophenylmethylene)-1-methyl piperidine-4-one (22) as bright yellow powder; mp 153° C. (violent decomposition). 1HNMR(CDCL3 δ 2.37 (s, 3H), 3.42 (s, 4H), 7.55 (s,2H). ##STR28## Yellow suspension resulted within minutes which Yellow solid was collected by vacuum filtration washed with water until the filtrate The yellow solid was dried further in vacuo